DE102007038879A1 - Process for the preparation and stabilization of functional metal nanoparticles in ionic liquids - Google Patents

Abstract

The The present invention describes a process for reductive preparation and stabilization of functional metal nanoparticles in ionic Liquids using elemental hydrogen, which makes it possible, by suitable choice of the used ionic liquid particle size and adjust the size distribution.

Description

The The present invention describes a process for reductive preparation and stabilization of functional metal nanoparticles in ionic Liquids using elemental hydrogen, the it makes it possible, by suitable choice of the used ionic Liquid the particle size and the To adjust size distribution.

Nanomaterials, ie materials with a particle size in the nanometer range, represent a new class of materials, which is of increasing importance for more and more technical areas. In most cases, nanomaterials are inorganic in nature, eg. As metals, metal oxides, metal phosphates, metal alloys or non-metals, but there are also organic nanomaterials. Above all, nanoparticles are characterized by the fact that they have a huge surface area relative to their volume, which means that they have far more atoms on the surface compared to materials with larger particle sizes. This often explains the special properties of nanomaterials, which can be used to improve or completely new properties of well-known materials and thereby open up new areas of application [ G. Schmid, Nanoparticles: From Theory to Application, Wiley-VCH, Weinheim, 2003, pages 1-434 ].

Metal nanoparticles are already widely used in various fields of chemistry and materials science. As a component of hybrid materials they can give the material new properties or existing physical or mechanical properties, eg. B. increase the electrical conductivity, thermal conductivity or resistance to breakage, while reducing weight. Nanoscale metal powders can be sintered without pressure and at lower temperatures. The resulting materials are characterized by greater compactness and improved mechanical properties. Nanoscale silver gives workpieces antimicrobial properties when applied in the form of a coating or added as a dopant to the material. This property is used in particular in the field of sanitary facilities, in the food and hygiene sector, eg. As in dispensing covers for hospitals, housing of medical equipment or in refrigerators. Furthermore, nanomaterials can often be used as efficient catalysts for a wide variety of processes [ D. Astruc, Nanoparticles and Catalysis, Wiley-VCH, Weinheim, 2007, pp. 1-634 ]. An industrially very important oxidation process is, for example, the conversion of olefins into epoxides [ K. Weissermel, HJ Arpe, Industrial Organic Chemistry, 4th edition, Wiley-VCH, Weinheim, 2003, pp. 145-192 and 267-312 ; BK Hodnett, Heterogeneous Catalytic Oxidation, Wiley-VCH, Weinheim, 2000, pages 160-188 ]. Oxidatively produced petroleum products, eg. As acrylates, are important monomers or intermediates for the chemical and pharmaceutical industries. Catalytically active, stabilized metal nanoparticles, in particular silver nanoparticles, can also provide valuable services for their production and lead to more efficient processes.

Several processes are already available for the production of metal nanoparticles, which are briefly explained below [ CNR Rao, A. Muller, A. Cheetham, The Chemistry of Nanomaterials: Synthesis, Properties and Applications, Wiley-VCH, Weinheim, 2004, pages 1-741 ; B. Bhushan, Springer Handbook of Nanotechnology, 2nd edition, Springer, Berlin, 2007, pages 1-1916 ].

(1) Steam condensation method:

at Steam condensation process, eg. As CVD or PVD, the metals evaporated in vacuo and then quenched deposited in nanoscale powders. Is the quenching in a Inert gas atmosphere, metal nanoparticles are obtained. In the presence of oxygen, however, nanoscale metal oxides fall in the presence of nitrogen, metal nitride nanoparticles getting produced. In a special form of this procedure will be CVD precursors, ie metal compounds, in the gas phase with formation thermally decomposed by nanoparticles. These gas phase methods will be relatively rare for the production of metal nanoparticles used. To their biggest disadvantages count the very high investment requirements and the ongoing process costs, caused by the vacuum generation and metal evaporation. About that In addition, these are the resulting particle sizes and size distributions difficult by choice the process conditions controllable.

(2) milling method:

A Another production method for nanoparticles is the milling process. Here, the comminution of microscale materials in special nanomills. Because the grinding at the nanometer level is very energy consuming, this method has for the Large-scale industry proved uneconomic. In addition, can contamination of the nanopowders by the grinding materials used come.

(3) wet-chemical methods:

By chemical methods, eg. As the sol-gel method or the wet-chemical Reduction, the shape and size of the Control nanoparticles much better. The choice of a suitable surface-active Stoffes (surfactants) enables the production of many metal and metal oxide nanoparticles in precipitation reactions. The biggest Disadvantage of this procedure is that impurities from the Reaction solution, for. B. unreacted starting materials or reagents, can find in the nanopowders and these therefore consuming and dried under controlled conditions and dried Need to become. As substrates are cost reasons in most cases metal halides (preferably chlorides) used; the price of the much better suitable alkoxides leads at a much higher cost and would be in many Cases make the process uneconomical. About that In addition, reaction media are often toxic, combustible and volatile organic solvents used, which is difficult due to the entry of the reagents usually difficult or not at all reusable. Due to the unavoidable use of surfactants for stabilization also much of the surface the nanoparticles of stabilizer molecules prove what the usable surface of the particles for the further Use as a catalyst or for a subsequent Functionalization greatly reduced and produced in this way Metal nanoparticles often unusable for these purposes power.

(4) Electrochemical methods:

in the Comparison to the aforementioned methods of nanoparticle production For example, electrochemical processes are much more efficient and reliable. By way of electrochemical reduction can be both Metal as well as metal oxide nanoparticles - the latter by Oxidation of the metal nanoparticles formed by the reduction process by an added oxidizing agent or atmospheric oxygen in situ - from produce the respective metals or metal salts in high purity. The findings from the metal industry about electrical refining of metals are used here. Continue to stand out electrochemical processes especially in comparison to the steam condensation process through much higher efficiency. Indeed it is after the electrochemical production of nanoparticles As before, the resulting particle sizes are difficult and the size distributions by appropriate choice to control the process parameter. Another disadvantage of Electrochemical process is that so far they only manufacture allow smaller amounts of nanopowder. Furthermore, come too here often organic solvents and surface-blocking Stabilizers for use.

The aim of the present invention is therefore to provide a process for the preparation and stabilization of functional metal nanoparticles that avoids the disadvantages of the above-mentioned processes by the use of ionic liquids as the reaction medium and elemental hydrogen as the reducing agent. That the generation of nanocrystalline deposits on a substrate is advantageously possible by electrochemical reduction from ionic liquids has already been shown elsewhere [M. Bukowski, F. Endres, R. Hempelmann, H. Natter, Offenlegungsschrift DE10108893 , 2002]. The possibility of producing catalytically active iridium and rhodium nanoparticles by the reduction of corresponding metal salts with hydrogen in ionic liquids is known [ GS Fonseca, AP Umpierre, PFP Fichtner, SR Teixeira, J. Dupont, Chem. Eur. J. 2003, 9, 3263-3269 ]. The stabilization of transition-metal nanoparticles by ionic liquids based on the core-shell principle and the resulting possibility of producing functional, catalytically active metal nanoparticles has also already been described. M. Antonietti, D. Kuang, B. Smarly, Y. Zhou, Angew. Chem. 2004, 116, 5096-5100 ; D. Astruc, F. Lu, JR Aranzaes, Angew. Chem. 2005, 117, 8062-8083 ].

Ionic liquids are defined liquid compounds exclusively composed of ions, which differ from classic molten salts mainly due to the unusually low temperatures (preferably <100 ° C.), in which they are in the liquid state of aggregation [ T. Welton, Chem. Rev. 1999, 99, 2071-2083 ; P. Wasserscheid, W. Keim, Angew. Chem. 2000, 112, 3926-3945 ; P. Wasserscheid, T. Welton, Tonic Liquids in Synthesis, Wiley-VCH, Weinheim, 2003, pp. 1-364 ]. In addition, ionic liquids have negligible vapor pressure, high thermal, chemical and electrochemical stability, and have versatile miscibility with water and organic solvents, which can be used to advantage in productions or product recovery or catalyst recovery.

It has now been found that functional, stable metal nanoparticles with a narrow size distribution can advantageously be prepared by reduction of suitable metal salts with elemental hydrogen in ionic liquids, preferably in the presence of a nitrogen base serving as proton scavengers, and that the size of the metal nanoparticles formed in the reduction process can be controlled by suitable choice of the ionic liquid, ie by the use of anions and cations of a certain size. The reduction is carried out in a stainless steel autoclave at elevated temperature and under hydrogen pressure. Typically, a high purity metal salt is dissolved at room temperature in a suitable ionic liquid. A sufficient solubility of the metal salt in the ionic liquid used is a prerequisite for the applicability of the present method. Subsequently, the solution is transferred to the autoclave and dried under high vacuum. Thereafter, the autoclave is filled directly with hydrogen and the reaction mixture is heated. After cooling, the nanoparticles formed can be separated off from the ionic liquid by centrifuging, so that the ionic liquid, if appropriate after an intermediate purification step, can be reused for further reactions. Alternatively, the obtained nanoparticle dispersion can also be used directly. The process will be explained below using the example of the preparation of silver nanoparticles.

Some silver (I) salts, e.g. Example, silver (I) tetrafluoroborate (AgBF ₄ ), silver (I) hexafluorophosphate (AgPF ₆ ) or silver (I) trifluoromethanesulfonate (AgOTf), can be in ionic liquids, eg. B. 1-butyl-3-methyl-imidazolium tetrafluoroborate (BMIM-BF ₄ ), 1-butyl-3-methyl-imidazolium hexafluorophosphate (BMIM-PF ₆ ), 1-butyl-3-methyl-imidazolium trifluoromethanesulfonate ( BMIM-OTf) or butyltrimethylammonium bis (trifluoromethylsulfonyl) imide (N _1,1,1,4 -NTf ₂ ), and reduced by hydrogen to silver nanoparticles. Is the acid formed in the reduction of hydrogen and the anion of the salt used, z. B. tetrafluoroboric acid (HBF ₄ ), hexafluorophosphoric acid (HPF ₆ ), trifluoromethanesulfonic acid (TfOH) or bis (trifluoromethylsulfonyl) imide (HNTf ₂ ), not by an added proton scavenger - preferably the underlying ionic liquid used nitrogen base - bound, the uniform particle formation inhibited because the stabilizing core-shell structure of nanoparticles and ionic liquid is disturbed. There is an agglomeration of the formed nanoparticles, and a very broad size distribution results, s. 1 ,

On the other hand, if the reduction is carried out in the presence of a proton scavenger, the agglomeration of the nanoparticles formed is prevented. Dispersions of finely divided, almost monodisperse nanoparticles in the ionic liquid are obtained. 2 ,

It demonstrate:

1 : TEM image of Ag nanoparticles prepared in BMIM-OTf from AgOTf without addition of a proton scavenger

2 : TEM image of Ag nanoparticles prepared in BMIM-BF ₄ from AgBF ₄ with addition of 1-butylimidazole as proton scavenger

3 : Scheme for the synthesis of metal nanoparticles by reduction of metal salts with hydrogen in ionic liquids using the example of Ag nanoparticles prepared from AgOTf and BMIM-OTf with addition of 1-butylimidazole as proton scavenger.

4 : Plot of the anion size (molar volumes) of the ionic liquid used against the particle size of the resulting Ag nanoparticles.

Particularly suitable proton scavengers are those materials which form cations through the uptake of protons whose molar volume corresponds approximately to the size of the cations of the ionic liquid used. Particularly preferred here is the ionic liquid underlying nitrogen base used. This can after the reaction by neutralization, for. B. with sodium hydroxide, released again, be separated from the ionic liquid and reused, s. 3 ,

• (*) = in Abwesenheit eines Protonenfängers

According to the core-shell principle, the stabilization of nanoparticles in ionic liquids occurs by the formation of alternating layers of anions and cations around the core. The thickness of the shell is dependent on the molar volume of the ions of the ionic liquid used. It is generally believed that the first ionic layer directly surrounding the nanoparticles is composed of anions. It follows that the anions of the ionic liquid should have the greatest influence on the size and stability of the nanoparticles. Table 1: _{Ionic liquid} Used Ag salt Molar volume of the anion [nm ³ ] Mean particle size of the Ag nanoparticles [nm] BMIM-BF ₄ AgBF ₄ 0.073 ± 0.009 2.80 ± 0.78 BMIM-PF ₆ AgPF ₆ 0.109 ± 0.008 4.36 ± 1.25 BMIM OTf AgOTf 0.131 ± 0.015 7.65 ± 4.50 (*) N _1,1,1,4 -NTf ₂ AgOTf 0.232 ± 0.015 26.08 ± 6.39

• (*) = in the absence of a proton catcher

In fact, it has now been found that, according to the present method, different particle sizes can be set depending on the anions of the ionic liquids used, wherein there is a linear relationship between the molar volume of the anion and the average particle size of the nanoparticles obtained, as in Tables 1 and 4 shown.

table 1 shows the dependence of the particle size the obtained Ag nanoparticles of the anion sizes (molar volumes) of the ionic liquid used.

A Variation of the cation of the ionic liquid used has only a minor influence on the particle size, but can also be used as a fine adjustment option the particle size are used. With show metal nanoparticles prepared by the present process Size distributions ≤ 30%.

The significant advantages of the present invention are therefore that by the use of ionic liquids as the reaction medium Metal nanoparticles in a new economical, energy-efficient and environmentally friendly process without the use of toxic, flammable and volatile solvents can be. Furthermore, no separate surface active Substances needed to stabilize the nanoparticles, which prove the usable surface of the resulting nanoparticles and in particular to reduce their catalytic activity. Thus, solely by the presence of the ionic Liquid and the associated strong electrostatic Stabilization of "naked" metal nanoparticles on gentle Be made way. The use of hydrogen as a "residue-free" reducing agent also allows nanoparticles in high To produce purity. Furthermore, the method described here basically also for the production and insulation of metal nanoparticles on a larger scale geeingnet. The initial dispersions of nanoparticles in ionic liquids can also directly used in catalytic processes. Another essential Advantage of the present invention results from the controllability the particle size and size distribution by suitable choice of the ionic liquid used, which in turn gives the possibility of controllability of the catalytic Activity of metal nanoparticles results.

The The present process is suitable in principle for the production of Nanoparticles of all metals in ionic liquids soluble salts and their salts with hydrogen reduce to the appropriate metal. Without restriction The general public prefers nanoparticles of transition metals, d. H. Metals of Groups 3 to 12 of the Periodic Table, after Produce method described here. As particularly preferred Metals are silver (Ag), copper (Cu), gold (Au), nickel (Ni), Palladium (Pd), platinum (Pt), cobalt (Co), rhodium (Rh), iridium (Ir), iron (Fe), ruthenium (Ru), osmium (Os), zinc (Zn), cadmium (Cd), manganese (Mn), rhenium (Re), chromium (Cr), molybdenum (Mo), Tungsten (W), vanadium, niobium (Nb), tantalum (Ta), titanium (Ti), zirconium (Zr), hafnium (Hf), scandium (Sc) and yttrium (Y).

Ionic liquids in the sense of the present invention are preferably salts of the general formula which are composed of cations [Q ^{n +} ] and anions [Z ^m- ] [Q ^{n +} ] _m [Z ^m- ] _n with n = m or n ≠ m and 1 ≦ n ≦ 4 and 1 ≦ m ≦ 4 including mixtures of several such salts having a melting point <180 ° C, preferably <120 ° C and most preferably <100 ° C, wherein those ionic liquids are particularly preferred in which n = m = 1.

For example, without limitation of generality, suitable cations [Q ^{n +} ] are

(I) Imidazolium cations of the general structure:

(II) Ammonium cations of the general structure:

(III) pyrrolidinium cations of the general structure:

(IV) piperidinium cations of the general structure:

(V) pyridinium cations of the general structure:

(VI) Morpholinium cations of the general structure:

(VII) guanidinium cations of the general structure:

(VII) Benzotriazolium cations of the general structure:

(IX) Quinolinium cations of the general structure:

(X) isoquinolinium cations of the general structure:

(XI) pyrazolium cations of the general structure:

(XII) 1,4-diazabicyclo [2.2.2] octane-1-ium cations of the general structure:

(XIII) 1,2,4-triazolium cations of the general structure:

(XIV) pyridazinium cations of the general structure:

(XV) pyrimidinium cations of the general structure:

(XVI) pyrazinium cations of the general structure:

(XVII) 1,3,5-triazinium cations of the general structure:

(XVIII) 1,2,3-triazolium cations of the general structure:

(XIX) piperazinium cations of the general structure:

(XX) oxazolium cations of the general structure:

(XXI) oxazolidinium cations of the general structure:

(XXII) Thiazolium cations of the general structure:

(XXIII) Quinoxalinium cations of the general structure:

(XXIV) benzimidazolium cations of the general structure:

(XXV) imidazolidinium cations of the general structure:

(XXVI) indolinium cations of the general structure:

(XXVII) thiomorpholium cations of the general structure:

• • die Reste R1 bis R13 unabhängig voneinander für Wasserstoff oder einen einbindigen, Kohlenstoff enthaltenden organischen, gesättigten oder ungesättigten, linearen oder verzweigten, acyclischen oder cyclischen, aliphatischen, aromatischen oder araliphatischen, unsubstituierten, teilweise oder vollständig halogenierten oder durch 1 bis 5 Heteroatome oder funktionelle Gruppen unterbrochenen oder substituierten Rest mit 1 bis 30 Kohlenstoffatomen;
• • zwei benachbarte Reste aus der Reihe R1 bis R13 zusammen auch für einen zweibindigen, Kohlenstoff enthaltenden organischen, gesättigten oder ungesättigten, linearen oder verzweigten, acyclischen oder cyclischen, aliphatischen, aromatischen oder araliphatischen, unsubstituierten, teilweise oder vollständig halogenierten oder durch 1 bis 5 Heteroatome oder funktionelle Gruppen unterbrochenen oder substituierten Rest mit 1 bis 30 Kohlenstoffatomen.

In the above-mentioned general structures (I) to (XXVII):

• • the radicals R 1 to R 13 independently of one another represent hydrogen or a monovalent carbon ent containing organic, saturated or unsaturated, linear or branched, acyclic or cyclic, aliphatic, aromatic or araliphatic, unsubstituted, partially or completely halogenated or interrupted by 1 to 5 heteroatoms or functional groups or substituted radical having 1 to 30 carbon atoms;
• • two adjacent radicals from the series R1 to R13 together also represent a divalent carbon-containing organic, saturated or unsaturated, linear or branched, acyclic or cyclic, aliphatic, aromatic or araliphatic, unsubstituted, partially or completely halogenated or by 1 to 5 heteroatoms or functional groups are interrupted or substituted radicals having 1 to 30 carbon atoms.

When particularly preferred heteroatoms which occur in the radicals R1 to R13 may be oxygen, sulfur, selenium, tellurium, nitrogen, Called phosphorus and silicon. In principle, the radicals R1 to R13 either via a carbon atom or a heteroatom be bound.

preferred functional groups which can occur in the radicals R1 to R13, are in particular hydroxyl, carbonyl, carboxyl, carboxamido, Amino and cyano groups. As halogens its fluorine, chlorine, bromine and called iodine.

• • die unsymmetrisch 1,3-dialkylierten, nicht protischen Imidazolium-Kationen 1-Ethyl-3-methyl-imidazolium, 1-Methyl-3-propyl-imidazolium, 1-Isopropyl-3-methyl-imidazolium, 1-Butyl-3-methyl-imidazolium, 1-Methyl-3-pentyl- imidazolium, 1-Hexyl-3-methyl-imidazolium, 1-Heptyl-3-methyl-imidazolium, 1-Methyl-3-octyl-imidazolium, 1-Methyl-3-nonyl-imidazolium, 1-Decyl-3-methyl-imidazolium, 1-Methyl-3-undecyl-imidazolium, 1-Dodecyl-3-methyl-imidazolium, 1-Methyl-3-tridecyl-imidazolium, 1-Methyl-3-tetradecyl-imidazolium, 1-Methyl-3-pentadecyl-imidazolium, 1-Hexadecyl-3-methyl-imidazolium, 1-Methyl-3-octadecyl-imidazolium und 1-Eicosyl-3-methyl-imidazolium sowie 1-Butyl-3-ethyl-imidazolium, 1-Ethyl-3-hexyl-imidazolium, 1-Ethyl-3-octyl-imidazolium, 1-Decyl-3-ethyl-imidazolium, 1-Dodecyl-3-ethyl-imidazolium, 1-Ethyl-3-tetradecyl-imidazolium, 1-Ethyl-3-hexadecyl-imidazolium, 1-Ethyl-3-octadecyl-imidazolium, 1-Butyl-3-hexyl-imidazolium, 1-Butyl-3-octyl-imidazolium, 1-Butyl-3-decyl-imidazolium, 1-Butyl-3-dodecyl-imidazolium, 1-Butyl-3-tetradecyl-imidazolium, 1-Butyl-3-hexadecyl-imidazolium, 1-Butyl-3-octadecyl-imidazolium, 1-Hexyl-3-octyl-imidazolium, 1-Decyl-3-hexyl-imidazolium, 1-Dodecyl-3-hexyl-imidazolium, 1-Hexyl-3-tetradecyl-imidazolium, 1-Hexadecyl-3-hexyl-imidazolium, 1-Hexyl-3-octadecyl-imidazolium, 1-Decyl-3-octyl-imidazolium, 1-Dodecyl-3-octyl-imidazolium, 1-Octyl-3-tetradecyl-imidazolium, 1-Hexadecyl-3-octyl-imidazolium, 1-Octadecyl-3-octyl-imidazolium, 1-Decyl-3-dodecyl-imidazolium, 1-Decyl-3-tetradecyl-imidazolium, 1-Decyl-3-hexadecyl-imidazolium, 1-Decyl-3-octadecyl-imidazolium, 1-Dodecyl-3-tetradecyl-imidazolium, 1-Dodecyl-3-hexadecyl-imidazolium, 1-Dodecyl-3-octadecyl-imidazolium, 1-Hexadecyl-3-tetradecyl-imidazolium, 1-Octadecyl-3-tetradecyl-imidazolium und 1-Hexadecyl-3-octadecyl-imidazolium;
• • die symmetrisch 1,3-dialkylierten, nicht protischen Imidazolium-Kationen: 1,3-Dimethyl-imidazolium, 1,3-Diethyl-imidazolium, 1,3-Dipropyl-imidazolium, 1,3-Diisopropyl-imidazolium, 1,3-Dibutyl-imidazolium, 1,3-Dipentyl-imidazolium, 1,3-Dihexyl-imidazolium, 1,3-Diheptyl-imidazolium, 1,3-Dioctyl-imidazolium, 1,3-Dinonyl-imidazolium, 1,3-Didecyl-imidazolium, 1,3-Diundecyl-imidazolium, 1,3-Didodecyl-imidazolium, 1,3-Ditridecyl-imidazolium, 1,3-Ditetradecyl-imidazolium, 1,3-Dipentadecyl-imidazolium, 1,3-Dihexadecyl-imidazolium, 1,3-Dioctadecyl-imidazolium und 1,3-Dieicosyl-imidazolium;
• • die 1,2,3-trialkylierten, nicht protischen Imidazolium-Kationen: 1,2,3-Trimethyl-imidazolium, 1-Ethyl-2,3-dimethyl-imidazolium, 1,2-Dimethyl-3-propyl-imidazolium, 1-Isopropyl-2,3-dimethyl-imidazolium, 1-Butyl-2,3-dimethyl- imidazolium, 1,2-Dimethyl-3-pentyl-imidazolium, 1-Hexyl-2,3-dimethyl-imidazolium, 1-Heptyl-2,3-dimethyl-imidazolium, 1,2-Dimethyl-3-octyl-imidazolium, 1,2-Dimethyl-3-nonyl-imidazolium, 1-Decyl-2,3-dimethyl-imidazolium, 1,2-Dimethyl-3-undecyl-imidazolium, 1-Dodecyl-2,3-dimethyl-imidazolium, 1,2-Dimethyl-3-tridecyl-imidazolium, 1,2-Dimethyl-3-tetradecyl-imidazolium, 1,2-Dimethyl-3-pentadecyl-imidazolium, 1-Hexadecyl-2,3-dimethyl-imidazolium, 1,2-Dimethyl-3-octadecyl-imidazolium und 1-Eicosyl-2,3-dimethyl-imidazolium sowie 1,3-Diethyl-2-methyl-imidazolium, 1,3-Dibutyl-2-methyl-imidazolium, 1,3-Dihexyl-2-methyl-imidazolium, 2-Methyl-1,3-dioctyl-imidazolium, 1,3-Didecyl-2-methyl-imidazolium, 1,3-Didodecyl-2-methyl-imidazolium, 2-Methyl-1,3-ditetradecyl-imidazolium, 1,3-Dihexadecyl-2-methyl-imidazolium, 2-Methyl-1,3-dioctadecyl-imidazolium, 1,2-Diethyl-3-methyl-imidazolium und 1,2,3-Triethyl-imidazolium;
• • die 1,3,4,5-tetraalkylierten, nicht protischen Imidazolium-Kationen: 1,3,4,5-Tetramethyl-imidazolium, 1-Ethyl-3,4,5-trimethyl-imidazolium, 1-Butyl-3,4,5-trimethyl-imidazolium, 1-Hexyl-3,4,5-trimethyl-imidazolium, 1,4,5-Trimethyl-3-octyl-imidazolium, 1-Decyl-3,4,5-trimethyl-imidazolium, 1-Dodecyl-3,4,5-trimethyl-imidazolium, 1,4,5-Trimethyl-3-tetradecyl-imidazolium, 1-Hexadecyl-3,4,5-trimethyl-imidazolium und 1,4,5-Trimethyl-3-octadecyl-imidazolium;
• • die 1-alkylierten, protischen Imidazolium-Kationen: 1-Methyl-imidazolium, 1-Ethyl-imidazolium, 1-Propyl-imidazolium, 1-Isopropyl-imidazolium, 1-Butyl-imidazolium, 1-Pentyl-imidazolium, 1-Hexyl-imidazolium, 1-Heptyl-imidazolium, 1-Octyl-imidazolium, 1-Nonyl-imidazolium, 1-Decyl-imidazolium, 1-Undecyl-imidazolium, 1-Dodecyl-imidazolium, 1-Tridecyl-imidazolium, 1-Tetradecyl-imidazolium, 1-Pentadecyl-imidazolium, 1-Hexadecyl-imidazolium, 1-Octadecyl-imidazolium und 1-Eicosyl-imidazolium;
• • die 1,2-dialkylierten, protischen Imidazolium-Kationen: 1,2-Dimethyl-imidazolium, 1-Ethyl-2-methyl-imidazolium, 1-Methyl-2-propyl-imidazolium, 1-Isopropyl-2-methyl-imidazolium, 1-Butyl-2-methyl-imidazolium, 1-Methyl-2-pentyl-imidazolium, 1-Hexyl-2-methyl-imidazolium, 1-Heptyl-2-methyl-imidazolium, 1-Methyl-2-octyl-imidazolium, 1-Methyl-2-nonyl- imidazolium, 1-Decyl-2-methyl-imidazolium, 1-Methyl-2-undecyl-imidazolium, 1-Dodecyl-2-methyl-imidazolium, 1-Methyl-2-tridecyl-imidazolium, 1-Methyl-2-tetradecyl-imidazolium, 1-Methyl-2-pentadecyl-imidazolium, 1-Hexadecyl-2-methyl-imidazlium, 1-Methyl-2-octadecyl-imidazolium und 1-Eicosyl-2-methyl-imidazolium;
• • die 1,3- und 1,2,3-substituierten, nicht protischen Imidazolium-Kationen: 1-Methyl-3-vinyl-imidazolium, 1-Allyl-3-methyl-imidazolium, 1-Benzyl-3-methyl-imidazolium, 1-(2-Hydroxyethyl)-3-methyl-imidazolium, 1-(2-Hydroxyethyl)-2,3-dimethyl-imidazolium, 1-(2-Methoxyethyl)-3-methyl-imidazolium und 1-(2-Methoxyethyl)-2,3-dimethyl-imidazolium.

Particularly preferred cations of group (I) are

• The asymmetrically 1,3-dialkylated, nonprotic imidazolium cations 1-ethyl-3-methylimidazolium, 1-methyl-3-propylimidazolium, 1-isopropyl-3-methylimidazolium, 1-butyl-3-one methylimidazolium, 1-methyl-3-pentylimidazolium, 1-hexyl-3-methylimidazolium, 1-heptyl-3-methylimidazolium, 1-methyl-3-octylimidazolium, 1-methyl-3-yl nonylimidazolium, 1-decyl-3-methylimidazolium, 1-methyl-3-undecylimidazolium, 1-dodecyl-3-methylimidazolium, 1-methyl-3-tridecylimidazolium, 1-methyl-3- tetradecyl-imidazolium, 1-methyl-3-pentadecyl-imidazolium, 1-hexadecyl-3-methyl-imidazolium, 1-methyl-3-octadecyl-imidazolium and 1-eicosyl-3-methyl-imidazolium, and 1-butyl-3-ol ethyl imidazolium, 1-ethyl-3-hexylimidazolium, 1-ethyl-3-octylimidazolium, 1-decyl-3-ethylimidazolium, 1-dodecyl-3-ethylimidazolium, 1-ethyl-3-yl tetradecylimidazolium, 1-ethyl-3-hexadecylimidazolium, 1-ethyl-3-octadecylimidazolium, 1-butyl-3-hexylimidazolium, 1-butyl-3-octylimidazolium, 1-butyl-3-one decyl-imidazolium, 1-Bu tyl-3-dodecyl-imidazolium, 1-butyl-3-tetradecyl-imidazolium, 1-butyl-3-hexadecyl-imidazolium, 1-butyl-3-octadecyl-imidazolium, 1-hexyl-3-octyl-imidazolium, 1- Decyl-3-hexyl-imidazolium, 1-dodecyl-3-hexyl-imidazolium, 1-hexyl-3-tetradecyl-imidazolium, 1-hexadecyl-3-hexyl-imidazolium, 1-hexyl-3-octadecyl-imidazolium, 1- Decyl-3-octyl-imidazolium, 1-dodecyl-3-octyl-imidazolium, 1-octyl-3-tetradecyl-imidazolium, 1-hexadecyl-3-octyl-imidazolium, 1-octadecyl-3-octyl-imidazolium, 1 Decyl 3-dodecylimidazolium, 1-decyl-3-tetradecylimidazolium, 1-decyl-3-hexadecylimidazolium, 1-decyl-3-octadecylimidazolium, 1-dodecyl-3-tetradecylimidazolium, 1- Dodecyl-3-hexadecyl-imidazolium, 1-dodecyl-3-octadecyl-imidazolium, 1-hexadecyl-3-tetradecyl-imidazolium, 1-octadecyl-3-tetradecyl-imidazolium and 1-hexadecyl-3-octadecyl-imidazolium;
• • the symmetrically 1,3-dialkylated, non-protic imidazolium cations: 1,3-dimethylimidazolium, 1,3-diethylimidazolium, 1,3-dipropylimidazolium, 1,3-diisopropylimidazolium, 1,3 Dibutylimidazolium, 1,3-dipentylimidazolium, 1,3-dihexylimidazolium, 1,3-diheptylimidazolium, 1,3-dioctylimidazolium, 1,3-dinonylimidazolium, 1,3-didecyl imidazolium, 1,3-diundecylimidazolium, 1,3-didodecylimidazolium, 1,3-ditridecylimidazolium, 1,3-ditetradecylimidazolium, 1,3-dipentadecylimidazolium, 1,3-dihexadecylimidazolium , 1,3-dioctadecylimidazolium and 1,3-dicosylimidazolium;
• The 1,2,3-trialkylated non-protic imidazolium cations: 1,2,3-trimethylimidazolium, 1-ethyl-2,3-dimethylimidazolium, 1,2-dimethyl-3-propylimidazolium, 1-Isopropyl-2,3-dimethyl-imidazolium, 1-butyl-2,3-dimethyl-imidazolium, 1,2-dimethyl-3-pentyl-imidazolium, 1-hexyl-2,3-dimethyl-imidazolium, 1- Heptyl-2,3-dimethyl-imidazolium, 1,2-dimethyl-3-octyl-imidazolium, 1,2-dimethyl-3-nonyl-imidazolium, 1-decyl-2,3-dimethyl-imidazolium, 1,2- Dimethyl-3-undecyl-imidazolium, 1-dodecyl-2,3-dimethyl-imidazolium, 1,2-dimethyl-3-tridecyl-imidazolium, 1,2-dimethyl-3-tetradecyl-imidazolium, 1,2-dimethyl 3-pentadecylimidazolium, 1-hexadecyl-2,3-dimethylimidazolium, 1,2-dimethyl-3-octadecylimidazolium and 1-eicosyl-2,3-dimethylimidazolium, and also 1,3-diethyl-2- methylimidazolium, 1,3-dibutyl-2-methylimidazolium, 1,3-dihexyl-2-methylimidazolium, 2-methyl-1,3-dioctylimidazolium, 1,3-didecyl-2-methyl- imidazolium, 1,3-didodecyl-2-methyl-imidazolium, 2-methyl-1,3-ditetradecyl-imidazolium, 1, 3-dihexadecyl-2-methyl-imidazolium, 2-methyl-1,3-dioctadecyl-imidazolium, 1,2-diethyl-3-methyl-imidazolium and 1,2,3-triethyl-imidazolium;
• The 1,3,4,5-tetraalkylated non-protic imidazolium cations: 1,3,4,5-tetramethylimidazolium, 1-ethyl-3,4,5-trimethylimidazolium, 1-butyl-3, 4,5-trimethyl imidazolium, 1-hexyl-3,4,5-trimethyl-imidazolium, 1,4,5-trimethyl-3-octyl-imidazolium, 1-decyl-3,4,5-trimethyl-imidazolium, 1-dodecyl-3,4, 5-trimethylimidazolium, 1,4,5-trimethyl-3-tetradecylimidazolium, 1-hexadecyl-3,4,5-trimethylimidazolium and 1,4,5-trimethyl-3-octadecylimidazolium;
• • the 1-alkylated, protic imidazolium cations: 1-methylimidazolium, 1-ethylimidazolium, 1-propylimidazolium, 1-isopropylimidazolium, 1-butylimidazolium, 1-pentylimidazolium, 1-hexyl imidazolium, 1-heptylimidazolium, 1-octylimidazolium, 1-nonylimidazolium, 1-decylimidazolium, 1-undecylimidazolium, 1-dodecylimidazolium, 1-tridecylimidazolium, 1-tetradecylimidazolium , 1-pentadecyl-imidazolium, 1-hexadecyl-imidazolium, 1-octadecyl-imidazolium and 1-eicosyl-imidazolium;
• • the 1,2-dialkylated, protic imidazolium cations: 1,2-dimethylimidazolium, 1-ethyl-2-methylimidazolium, 1-methyl-2-propylimidazolium, 1-isopropyl-2-methylimidazolium , 1-butyl-2-methyl-imidazolium, 1-methyl-2-pentyl-imidazolium, 1-hexyl-2-methyl-imidazolium, 1-heptyl-2-methyl-imidazolium, 1-methyl-2-octyl-imidazolium , 1-methyl-2-nonylimidazolium, 1-decyl-2-methylimidazolium, 1-methyl-2-undecylimidazolium, 1-dodecyl-2-methylimidazolium, 1-methyl-2-tridecylimidazolium , 1-methyl-2-tetradecyl-imidazolium, 1-methyl-2-pentadecyl-imidazolium, 1-hexadecyl-2-methyl-imidazlium, 1-methyl-2-octadecyl-imidazolium and 1-eicosyl-2-methyl-imidazolium ;
• • the 1,3- and 1,2,3-substituted, non-protic imidazolium cations: 1-methyl-3-vinylimidazolium, 1-allyl-3-methylimidazolium, 1-benzyl-3-methylimidazolium , 1- (2-hydroxyethyl) -3-methylimidazolium, 1- (2-hydroxyethyl) -2,3-dimethylimidazolium, 1- (2-methoxyethyl) -3-methylimidazolium, and 1- (2-hydroxyethyl) -3-methylimidazolium; methoxyethyl) -2,3-dimethyl-imidazolium.

• • die quartären, nicht protischen Ammonium-Kationen: Tetramethyl-ammonium, Tetraethyl-ammonium, Tetrapropyl-ammonium, Tetraisopropyl-ammonium, Tetrabutyl-ammonium, Tetrapentyl-ammonium, Tetrahexyl-ammonium, Tetraheptyl-ammonium, Tetraoctyl-ammonium, Tetranonyl-ammonium, Tetradecyl-ammonium, Ethyl-trimethyl-ammonium, Trimethyl-propyl-ammonium, Isopropyl-trimethyl-ammonium, Butyl-trimethyl-ammonium, Trimethyl-pentyl-ammonium, Hexyl-trimethyl-ammonium, Heptyl-trimethyl-ammonium, Trimethyl-octyl-ammonium, Trimethyl-nonyl-ammonium, Decyl-trimethyl-ammonium, Dodecyl-trimethyl-ammonium, Trimethyl-tetradecyl-ammonium, Hexadecyl-trimethyl-ammonium, Trimethyl-octadecyl-ammonium, Triethyl-methyl-ammonium, Triethyl-propyl-ammonium, Triethyl-isopropyl-ammonium, Butyl-triethyl-ammonium, Triethyl-pentyl-ammonium, Triethyl-hexyl-ammonium, Triethyl-heptyl-ammonium, Triethyl-octyl-ammonium, Triethyl-nonyl-ammonium, Decyl-triethyl-ammonium, Dodecyl-triethyl-ammonium, Triethyl-tetradecyl-ammonium, Triethyl-hexadecyl-ammonium, Triethyl-octadecyl-ammonium, Tripropyl-undecyl-ammonium, Tributyl-methyl-ammonium, Tributyl-ethyl-ammonium, Tributyl-propyl-ammonium, Tributyl-isopropyl-ammonium, Tributyl-pentyl-ammonium, Tributyl-hexyl-ammonium, Tributyl-heptyl-ammonium, Tributyl-octyl-ammonium, Tributyl-nonyl-ammonium, Tributyl-decyl-ammonium, Tributyl-dodecyl-ammonium, Tributyl-tetradecyl-ammonium, Tributyl-hexadecyl-ammonium, Tributyl-octadecyl-ammonium, Trihexyl-methyl-ammonium, Ethyl-trihexyl-ammonium, Trihexyl-propyl- ammonium, Trihexyl-isopropyl-ammonium, Butyl-trihexyl-ammonium, Methyl-trioctyl-ammonium, Ethyl-trioctyl-ammonium, Trioctyl-propyl-ammonium, Isopropyl-trioctyl-ammonium, Butyl-trioctyl-ammonium, Diethyl-dimethyl-ammonium, Dimethyl-dipropyl-ammonium, Diisopropyl-dimethyl-ammonium, Dimethyl-dinonyl-ammonium, Didodecyl-dimethyl-ammonium, Diethyl-dipropyl-ammonium, Diethyl-diisopropyl-ammonium, Dibutyl-diethyl-ammonium, Diethyl-dihexyl-ammonium, Diethyl-diheptyl-ammonium, Diethyl-dioctyl-ammonium, Dibutyl-dihexyl-ammonium, Diheptyl-dipropyl-ammonium, 2-Hydroxyethyl-trimethyl-ammonium (Cholin) und Tris(2-hydroxyethyl)-methyl-ammonium;
• • die tertiären, protischen Ammonium-Kationen: Trimethyl-ammonium, Triethyl-ammonium, Tripropyl-ammonium, Triisopopyl-ammonium, Tributyl-ammonium, Tripentyl-ammonium, Trihexyl-ammonium, Triheptyl-ammonium, Trioctyl-ammonium, Diethyl-methyl-ammonium und Tris(2-hydroxyethyl)-ammonium;
• • die sekundären, protischen Ammonium-Kationen: Dimethyl-ammonium, Diethyl-ammonium, Dipropyl-ammonium, Diisopropyl-ammonium, Dibutyl-ammonium, Dipentyl-ammonium, Dihexyl-ammonium, Diheptyl-ammonium, Dioctyl-ammonium, Dinonyl-ammonium, Didecyl-ammonium, Didodecyl-ammonium und Bis(2-hydroxyethyl)-ammonium;
• • die primären, protischen Ammonium-Kationen: Methyl-ammonium, Ethyl-ammonium, Propyl-ammonium, Isopropyl-ammonium, Butyl-ammonium, Pentyl-ammonium, Hexyl-ammonium, Heptyl-ammonium, Octyl-ammonium, Nonyl-ammonium, Decyl-ammonium, Dodecyl-ammonium, Tetradecyl-ammonium, Hexadecyl-ammonium, Octadecyl-ammonium und 2-Hydroxyethyl-ammonium.

Particularly preferred cations of group (II) are

• The quaternary, non-protic ammonium cations: tetramethylammonium, tetraethylammonium, tetrapropylammonium, tetraisopropylammonium, tetrabutylammonium, tetrapentylammonium, tetrahexylammonium, tetraheptylammonium, tetraoctylammonium, tetranonylammonium, Tetradecyl-ammonium, ethyl-trimethyl-ammonium, trimethyl-propyl-ammonium, isopropyl-trimethyl-ammonium, butyl-trimethyl-ammonium, trimethyl-pentyl-ammonium, hexyl-trimethyl-ammonium, heptyl-trimethyl-ammonium, trimethyl-octyl- ammonium, trimethyl-nonyl-ammonium, decyl-trimethyl-ammonium, dodecyl-trimethyl-ammonium, trimethyl-tetradecyl-ammonium, hexadecyl-trimethyl-ammonium, trimethyl-octadecyl-ammonium, triethyl-methyl-ammonium, triethyl-propyl-ammonium, Triethyl-isopropyl-ammonium, butyl-triethyl-ammonium, triethyl-pentyl-ammonium, triethyl-hexyl-ammonium, triethyl-heptyl-ammonium, triethyl-octyl-ammonium, triethyl-nonyl-ammonium, decyl-triethyl-ammonium, dodecyl-ammonium triethylammonium, triethyltetradecylammonium, Trie thyl-hexadecyl-ammonium, triethyl-octadecyl-ammonium, tripropyl-undecyl-ammonium, tributyl-methyl-ammonium, tributyl-ethyl-ammonium, tributyl-propyl-ammonium, tributyl-isopropyl-ammonium, tributyl-pentyl-ammonium, tributyl hexyl-ammonium, tributyl-heptyl-ammonium, tributyl-octyl-ammonium, tributyl-nonyl-ammonium, tributyl-decyl-ammonium, tributyl-dodecyl-ammonium, tributyl-tetradecyl-ammonium, tributyl-hexadecyl-ammonium, tributyl-octadecyl ammonium, trihexylmethylammonium, ethyltrihexylammonium, trihexylpropylammonium, trihexylisopropylammonium, butyltrihexylammonium, methyltrioctylammonium, ethyltrioctylammonium, trioctylpropylammonium, Isopropyl-trioctyl-ammonium, butyl-trioctyl-ammonium, diethyl-dimethyl-ammonium, dimethyl-dipropyl-ammonium, diisopropyl-dimethyl-ammonium, dimethyl-dinonyl-ammonium, didodecyl-dimethyl-ammonium, diethyl-dipropyl-ammonium, diethyl- diisopropyl-ammonium, dibutyl-diethyl-ammonium, diethyl-dihexyl-ammonium, diethyl-diheptyl-ammonium, diet hyl dioctyl ammonium, dibutyl dihexyl ammonium, diheptyl dipropyl ammonium, 2-hydroxyethyl trimethyl ammonium (choline) and tris (2-hydroxyethyl) methyl ammonium;
• The tertiary, protic ammonium cations: trimethylammonium, triethylammonium, tripropylammonium, triisopopylammonium, tributylammonium, tripentylammonium, trihexylammonium, triheptylammonium, trioctylammonium, diethylmethylammonium and tris (2-hydroxyethyl) ammonium;
• The secondary, protic ammonium cations: dimethyl ammonium, diethyl ammonium, dipropyl ammonium, diisopropyl ammonium, dibutyl ammonium, dipentyl ammonium, dihexyl ammonium, diheptyl ammonium, dioctyl ammonium, dinonyl ammonium, didecyl ammonium, didodecylammonium and bis (2-hydroxyethyl) ammonium;
• The primary, protic ammonium cations: methyl ammonium, ethyl ammonium, propyl ammonium, isopropyl ammonium, butyl ammonium, pentyl ammonium, hexyl ammonium, heptyl ammonium, octyl ammonium, nonyl ammonium, decyl ammonium, dodecylammonium, tetradecylammonium, hexadecylammonium, octadecylammonium and 2-hydroxyethylammonium.

Particularly preferred cations of group (III) are:
1,1-Dimethyl-pyrrolidinium, 1-ethyl-1-methyl-pyrrolidinium, 1-methyl-1-propyl-pyrrolidinium, 1-butyl-1-methyl-pyrrolidinium, 1-hexyl-1-methyl-pyrrolidinium, 1 Methyl 1-octyl-pyrrolidinium, 1,1-diethyl-pyrrolidinium, 1-ethyl-1-propyl-pyrrolidinium, 1-ethyl-1-butyl-pyrrolidinium, 1-ethyl-1-hexyl-pyrrolidinium, 1-ethyl 1-octylpyrrolidinium, 1,1-dipropylpyrrolidinium, 1,1-dibutylpyrrolidinium, 1,1-dihexylpyrrolidinium and 1,1-dioctylpyrrolidinium.

Particularly preferred cations of group (IV) are:
1,1-Dimethyl-piperidinium, 1-ethyl-1-methyl-piperidinium, 1-methyl-1-propyl-piperidinium, 1-butyl-1-methyl-piperidinium, 1-hexyl-1-methyl-piperidinium, 1 Methyl 1-octyl-piperidinium, 1,1-diethyl-piperidinium, 1-ethyl-1-propyl-piperidinium, 1-ethyl-1-butyl-piperidinium, 1-ethyl-1-hexyl-piperidinium, 1-ethyl 1-octyl-piperidinium, 1,1-dipropyl-piperidinium, 1,1-dibutyl-piperidinium, 1,1-dihexyl-piperidinium and 1,1-dioctyl-piperidinium.

• • die 1-alkylierten Pyridinium-Kationen: 1-Methyl-pyridinium, 1-Ethyl-pyridinium, 1-Propyl-pyridinium, 1-Butyl-pyridinium, 1-Pentyl-pyridinium, 1-Hexyl-pyridinium, 1-Octyl-pyridinium, 1-Decyl-pyridinium, 1-Dodecyl-pyridinium, 1-Tetradecyl-pyridinium, 1-Hexadecyl-pyridinium und 1-Octadecyl-pyridinium;
• • die 1,2-dialkylierten Pyridinium-Kationen: 1,2-Dimethyl-pyridinium, 1-Ethyl-2-methyl-pyridinium, 2-Methyl-1-propyl-pyridinium, 1-Butyl-2-methyl-pyridinium, 2-Methyl-1-pentyl-pyridinium, 1-Hexyl-2-methyl-pyridinium, 2-Methyl-1-octyl-pyridinium, 1-Decyl-2-methyl-pyridinium, 1-Dodecyl-2-methyl-pyridinium, 2-Methyl-1-tetradecyl-pyridinium, 1-Hexadecyl-2-methyl-pyridinium und 2-Methyl-1-octadecyl-pyridinium sowie 1,2-Diethyl-pyridinium, 2-Ethyl-1-propyl-pyridinium, 1-Butyl-2-ethyl-pyridinium, 2-Ethyl-1-pentyl-pyridinium, 2-Ethyl-1-hexyl-pyridinium, 2-Ethyl-1-octyl-pyridinium, 1-Decyl-2-ethyl-pyridinium, 1-Dodecyl-2-ethyl-pyridinium, 2-Ethyl-1-tetradecyl-pyridinium, 2-Ethyl-1-hexadecyl-pyridinium und 2-Ethyl-1-octadecyl-pyridinium;
• • die 1,3-dialkylierten Pyridinium-Kationen: 1,3-Dimethyl-pyridinium, 1-Ethyl-3-methyl-pyridinium, 3-Methyl-1-propyl-pyridinium, 1-Butyl-3-methyl-pyridinium, 3-Methyl-1-pentyl-pyridinium, 1-Hexyl-3-methyl-pyridinium, 3-Methyl-1-octyl-pyridinium, 1-Decyl-3-methyl-pyridinium, 1-Dodecyl-3-methyl-pyridinium, 3-Methyl-1-tetradecyl-pyridinium, 1-Hexadecyl-3-methyl-pyridinium und 3-Methyl-1-octadecyl-pyridinium sowie 1,3-Diethyl-pyridinium, 3-Ethyl-1-propyl-pyridinium, 1-Butyl-3-ethyl-pyridinium, 3-Ethyl-1-pentyl-pyridinium, 3-Ethyl-1-hexyl-pyridinium, 3-Ethyl-1-octyl-pyridinium, 1-Decyl-3-ethyl-pyridinium, 1-Dodecyl-3-ethyl-pyridinium, 3-Ethyl-1-tetradecyl-pyridinium, 3-Ethyl-1-hexadecyl-pyridinium und 3-Ethyl-1-octadecyl-pyridinium;
• • die 1,4-dialkylierten Pyridinium-Kationen: 1,4-Dimethyl-pyridinium, 1-Ethyl-4-methyl-pyridinium, 4-Methyl-1-propyl-pyridinium, 1-Butyl-4-methyl-pyridinium, 4-Methyl-1-pentyl-pyridinium, 1-Hexyl-4-methyl-pyridinium, 4-Methyl-1-octyl-pyridinium, 1-Decyl-4-methyl-pyridinium, 1-Dodecyl-4-methyl-pyridinium, 4-Methyl-1-tetradecyl-pyridinium, 1-Hexadecyl-4-methyl-pyridinium und 4-Methyl-1-octadecyl-pyridinium;
• • die 1,3,5-trialkylierten Pyridinium-Kationen: 1,3,5-Trimethyl-pyridinium, 1-Ethyl-3,5-dimethyl-pyridinium, 3,5-Dimethyl-1-propyl-pyridinium, 1-Butyl-3,5-dimethyl-pyridinium, 3,5-Dimethyl-1-pentyl-pyridinium, 1-Hexyl-3,5-dimethyl-pyridinium, 3,5-Dimethyl-1-octyl-pyridinium, 1-Decyl-3,5-dimethyl-pyridinium, 1-Dodecyl-3,5-dimethyl-pyridinium, 3,5-Dimethyl-1-tetradecyl-pyridinium, 1-Hexadecyl-3,5-dimethyl-pyridinium und 3,5-Dimethyl-1-octadecyl-pyridinium.

Particularly preferred cations of group (V) are

• The 1-alkylated pyridinium cations: 1-methyl-pyridinium, 1-ethyl-pyridinium, 1-propyl-pyridinium, 1-butyl-pyridinium, 1-pentyl-pyridinium, 1-hexyl-pyridinium, 1-octyl-pyridinium , 1-decylpyridinium, 1-dodecylpyridinium, 1-tetradecylpyridinium, 1-hexadecylpyridinium and 1-octadecylpyridinium;
• The 1,2-dialkylated pyridinium cations: 1,2-dimethyl-pyridinium, 1-ethyl-2-methyl-pyridinium, 2-methyl-1-propyl-pyridinium, 1-butyl-2-methyl-pyridinium, 2 -Methyl-1-pentylpyridinium, 1-hexyl-2-methylpyridinium, 2-methyl-1-octylpyridinium, 1-decyl-2-methylpyridinium, 1-dodecyl-2-methylpyridinium, 2 -Methyl-1-tetradecylpyridinium, 1-hexadecyl-2-methylpyridinium and 2-methyl-1-octadecylpyridinium; and 1,2-diethylpyridinium, 2-ethyl-1-propylpyridinium, 1-butyl 2-ethyl-pyridinium, 2-ethyl-1-pentyl-pyridinium, 2-ethyl-1-hexyl-pyridinium, 2-ethyl-1-octyl-pyridinium, 1-decyl-2-ethyl-pyridinium, 1-dodecyl 2-ethylpyridinium, 2-ethyl-1-tetradecylpyridinium, 2-ethyl-1-hexadecylpyridinium and 2-ethyl-1-octadecylpyridinium;
• The 1,3-dialkylated pyridinium cations: 1,3-dimethyl-pyridinium, 1-ethyl-3-methyl-pyridinium, 3-methyl-1-propyl-pyridinium, 1-butyl-3-methyl-pyridinium, 3 -Methyl-1-pentylpyridinium, 1-hexyl-3-methylpyridinium, 3-methyl-1-octylpyridinium, 1-decyl-3-methylpyridinium, 1-dodecyl-3-methylpyridinium, 3 -Methyl-1-tetradecylpyridinium, 1-hexadecyl-3-methylpyridinium and 3-methyl-1-octadecylpyridinium; and 1,3-diethylpyridinium, 3-ethyl-1-propylpyridinium, 1-butyl 3-ethyl-pyridinium, 3-ethyl-1-pentyl-pyridinium, 3-ethyl-1-hexyl-pyridinium, 3-ethyl-1-octyl-pyridinium, 1-decyl-3-ethyl-pyridinium, 1-dodecyl 3-ethylpyridinium, 3-ethyl-1-tetradecylpyridinium, 3-ethyl-1-hexadecylpyridinium and 3-ethyl-1-octadecylpyridinium;
• The 1,4-dialkylated pyridinium cations: 1,4-dimethyl-pyridinium, 1-ethyl-4-methyl-pyridinium, 4-methyl-1-propyl-pyridinium, 1-butyl-4-methyl-pyridinium, 4 -Methyl 1-pentyl-pyridinium, 1-hexyl-4-methyl-pyridinium, 4-methyl-1-octyl-pyridinium, 1-decyl-4-methyl-pyridinium, 1-dodecyl-4-methyl-pyridinium, 4 Methyl 1-tetradecylpyridinium, 1-hexadecyl-4-methylpyridinium and 4-methyl-1-octadecylpyridinium;
• The 1,3,5-trialkylated pyridinium cations: 1,3,5-trimethyl-pyridinium, 1-ethyl-3,5-dimethyl-pyridinium, 3,5-dimethyl-1-propyl-pyridinium, 1-butyl 3,5-dimethyl-pyridinium, 3,5-dimethyl-1-pentyl-pyridinium, 1-hexyl-3,5-dimethyl-pyridinium, 3,5-dimethyl-1-octyl-pyridinium, 1-decyl-3 , 5-dimethyl-pyridinium, 1-dodecyl-3,5-dimethyl-pyridinium, 3,5-dimethyl-1-tetradecyl-pyridinium, 1-hexadecyl-3,5-dimethyl-pyridinium and 3,5-dimethyl-1 octadecyl-pyridinium.

Particularly preferred cations of group (VI) are:
4,4-dimethyl-morpholinium, 4-ethyl-4-methyl-morpholinium, 4-methyl-4-propyl-morpholinium, 4-butyl-4-methyl-morpholinium, 4-hexyl-4-methyl-morpholinium, 4- Methyl 4-octyl-morpholinium, 4,4-diethyl-morpholinium, 4-ethyl-4-propyl-morpholinium, 4-ethyl-4-butyl-morpholinium, 4-ethyl-4-hexyl-morpholinium, 4-ethyl 4-octyl-morpholinium, 4,4-dipropyl-morpholinium, 4,4-dibutyl-morpholinium, 4,4-dihexyl-morpholinium and 4,4-dioctyl-morpholinium.

• • die offenkettigen Guanidinium-Kationen: Guanidinium, 1,1,3,3-Tetramethyl-guanidinium, 1,1,3,3,4-Pentamethyl-guanidinium, 4-Ethyl-1,1,3,3-tetramethyl-guanidinium, 1,1,3,3-Tetramethyl-4-propyl-guanidinium, 4-Isopropyl-1,1,3,3-tetramethyl-guanidinium, 4-Butyl-1,1,3,3-tetramethyl-guanidinium, 1,1,3,3,4,4-Hexamethyl-guanidinium, 4-Ethyl-1,1‚3,3,4-pentamethyl-guanidinium, 1,1,3,3,4-Pentamethyl-4-propyl- guanidinium, 4-Isopropyl-1,1,3,3,4-pentamethyl-guanidinium, 4-Butyl-1,1,3,3,4-pentamethyl-guanidinium, 1,1,3,3-Tetraethyl-4,4-dimethyl-guanidinium, 1,1,3,3-Tetrabutyl-4,4-dimethyl-guanidinium, 1,1,3,3-Tetrahexyl-4,4-dimethyl-guanidinium, 4,4-Dimethyl-1,1,3,3-tetraoctyl-guanidinium und 1,3-Diethyl-1,3-dibutyl-4,4-dimethyl-guanidinium;
• • die cyclischen Guanidinium-Kationen: 1,3-Ethylen-1,3,4-trimethyl-guanidinium, 4-Ethyl-1,3-ethylen-1,3-dimethyl-guanidinium, 1,3-Ethylen-1,3-dimethyl-4-propyl-guanidinium, 4-Butyl-1,3-ethylen-1,3-dimethyl-guanidinium, 1,3-Ethylen-1,3,4,4-tetramethyl-guanidinium, 4-Ethyl-1,3-ethylen-1,3,4-trimethyl-guanidinium, 1,3-Ethylen-1,3,4-trimethyl-4-propyl-guanidinium und 4-Butyl-1,3-ethylen-1,3,4-trimethyl-guanidinium sowie 1,3,4-Trimethyl-1,3-propylen-guanidinium, 4-Ethyl-1,3-dimethyl-1,3-propylen-guanidinium, 1,3-Dimethyl-4-propyl-1,3-propylen-guanidinium, 4-Butyl-1,3-dimethyl-1,3-propylen-guanidinium, 1,3,4,4-Tetramethyl-1,3-propylen-guanidinium, 4-Ethyl-1,3,4-trimethyl-1,3-propylen-guanidinium, 1,3,4-Trimethyl-4-propyl-1,3-propylen-guanidinium und 4-Butyl-1,3,4-trimethyl-1,3-propylen-guanidinium.

Particularly preferred cations of group (VII) are

• The open-chain guanidinium cations: guanidinium, 1,1,3,3-tetramethyl-guanidinium, 1,1,3,3,4-pentamethyl-guanidinium, 4-ethyl-1,1,3,3-tetra methyl-guanidinium, 1,1,3,3-tetramethyl-4-propyl-guanidinium, 4-isopropyl-1,1,3,3-tetramethyl-guanidinium, 4-butyl-1,1,3,3-tetramethyl- guanidinium, 1,1,3,3,4,4-hexamethyl-guanidinium, 4-ethyl-1,1,3,3,4-pentamethyl-guanidinium, 1,1,3,3,4-pentamethyl-4- propylguanidinium, 4-isopropyl-1,1,3,3,4-pentamethyl-guanidinium, 4-butyl-1,1,3,3,4-pentamethyl-guanidinium, 1,1,3,3-tetraethyl- 4,4-dimethyl-guanidinium, 1,1,3,3-tetrabutyl-4,4-dimethyl-guanidinium, 1,1,3,3-tetrahexyl-4,4-dimethyl-guanidinium, 4,4-dimethyl 1,1,3,3-tetraoctyl-guanidinium and 1,3-diethyl-1,3-dibutyl-4,4-dimethyl-guanidinium;
• The cyclic guanidinium cations: 1,3-ethylene-1,3,4-trimethyl-guanidinium, 4-ethyl-1,3-ethylene-1,3-dimethyl-guanidinium, 1,3-ethylene-1,3 -dimethyl-4-propyl-guanidinium, 4-butyl-1,3-ethylene-1,3-dimethyl-guanidinium, 1,3-ethylene-1,3,4,4-tetramethyl-guanidinium, 4-ethyl-1 , 3-ethylene-1,3,4-trimethyl-guanidinium, 1,3-ethylene-1,3,4-trimethyl-4-propyl-guanidinium and 4-butyl-1,3-ethylene-1,3,4 trimethyl-guanidinium and 1,3,4-trimethyl-1,3-propylene-guanidinium, 4-ethyl-1,3-dimethyl-1,3-propylene-guanidinium, 1,3-dimethyl-4-propyl-1 , 3-propylene-guanidinium, 4-butyl-1,3-dimethyl-1,3-propylene-guanidinium, 1,3,4,4-tetramethyl-1,3-propylene-guanidinium, 4-ethyl-1,3 , 4-trimethyl-1,3-propylene-guanidinium, 1,3,4-trimethyl-4-propyl-1,3-propylene-guanidinium and 4-butyl-1,3,4-trimethyl-1,3-propylene guanidinium.

Particularly preferred cations of group (VII) are:
1-Butyl-3-methylbenzotriazolium, 1-butyl-3-ethylbenzotriazolium, 1-butyl-3-propylbenzotriazolium, 1,3-dibutylbenzotriazolium and 1-benzyl-3-methylbenzotriazolium.

Particularly preferred cations of the group (IX) are
1-methyl quinolinium, 1-ethyl quinolinium, 1-propyl quinolinium, 1-butyl quinolinium, 1-hexyl quinolinium, 1-octyl quinolinium, 1-decyl quinolinium, 1-dodecyl quinolinium, 1- Tetradecyl quinolinium, 1-hexadecyl quinolinium and 1-octadecyl quinolinium.

Particularly preferred cations of the group (X) are:
1-methylisoquinolinium, 1-ethylisoquinolinium, 1-propylisoquinolinium, 1-butylisoquinolinium, 1-hexylisoquinolinium, 1-octylisoquinolinium, 1-decylisoquinolinium, 1-dodecylisoquinolinium, 1 Tetradecyl-isoquinolinium, 1-hexadecyl-isoquinolinium and 1-octadecyl-isoquinolinium.

Particularly preferred cations of the group (XI) are:
1,2-dimethylpyrazolium, 1,2,4-trimethylpyrozolium, 1,2-diethylpyrazolium and 1,2,4-triethylpyrazolium.

Particularly preferred cations of the group (XII) are:
1-Methyl-1,4-diazabicyclo [2.2.2] octane-1-ium, 1-ethyl-1,4-diazabicyclo [2.2.2] octane-1-ium, 1-propyl-1,4-diene diazabicyclo [2.2.2] octane-1-ium, 1-butyl-1,4-diazabicyclo [2.2.2] octane-1-ium, 1-pentyl-1,4-diazabicyclo [2.2.2] octane 1-ium, 1-hexyl-1,4-diazabicyclo [2.2.2] octane-1-ium, 1-heptyl-1,4-diazabicyclo [2.2.2] octane-1-ium, 1-octyl 1,4-diazabicyclo [2.2.2] octane-1-ium, 1-nonyl-1,4-diazabicyclo [2.2.2] octane-1-ium and 1-decyl-1,4-diazabicyclo [2.2 .2] octane-1-ium.

When Anions for are in principle all anions suitable, the in conjunction with cations according to the invention an ionic liquid in the context of the present invention being able to lead.

Without limitation of generality, suitable anions [Z ^m- ] are, for example

(A) the halides

• Fluoride (F ^- ), chloride (Cl ^- ), bromide (Br ^- ) and iodide (I ^- );

(B) the polyhalides

• Tribromide (Br ₃ ^- ), triiodide (I ₃ ^- ), iododibromide (IBr ₂ ^- ), diiodobromide (I ₂ Br ^- ), pentaiodide (I ₅ ^- ) and heptaiodide (I ₇ ^- );

(C) the pseudohalides

• Cyanide (CN ^- ), cyanate (OCN ^- ), thiocyanate (SCN ^- ), selenocyanate (SeCN ^- ) and dicyanamide [N (CN) ₂ ^- ];

(D) the phosphates

• of the general formulas H ₂ PO ₄ ^- , HPO ₄ ^2- , PO ₄ ^3- , (R ^A O) (R ^B O) PO ₄ ^- , H (R ^A O) PO ₃ ^- and (R ^A O) PO ₃ ^2- and hexafluorophosphate (PF ₆ ^- ), tris (pentafluoroethyl) trifluorophosphate [(C ₂ F ₅ ) ₃ PF ₃ ^- ], tris (heptafluoropropyl) trifluorophosphate [(C ₃ F ₇ ) ₃ PF ₃ ^- ] and tris ( nonafluorobutyl) trifluorophosphate [(C ₄ F ₉ ) ₃ PF ₃ ^- ];

(E) the phosphites

• of the general formula (R ^A O) (R ^B O) PO ^- ;

(F) the phosphonates

• of the general formulas R ^A HPO ₃ ^- , R ^A PO ₃ ^2- and R ^A (R ^B O) PO ₂ ^- ;

(G) the phosphinates

• the general formula R ^A R ^B PO ₂ ^- ;

(H) the sulfates

• of the general formulas HSO ₄ ^- , SO ₄ ^2- and (R ^A O) SO ₃ ^- ;

(I) the sulfonates

• the general formula R ^A SO ₃ ^- ;

(J) the bristle

• of the general formulas BO ₃ ^3-, HBO ₃ ^2-, H ₂ BO ^3, (R ^A O) (R ^B O) BO ^-, (R ^A O) HBO ₂ ^-, (R ^A O) BO ₂ ^2- , (R ^A O) (R ^B O) (R ^C O) (R ^D O) B ^- and tetrafluoroborate (BF ₄ ^- ), tetrachloroborate (BCl ₄ ^- ), tetracyanoborate ([B (CN) ₄ ^- ], bis (oxalato) borate [B (O ₂ C-CO ₂ ) ₂ ^- ], bis (malonato) borate [B (O ₂ C-CH ₂ -CO ₂ ) ₂ ^- ], bis (benzene-1,2-diolato) borate [B (OC ₆ H ₄ O) ₂ ^- ], bis (2,2'-biphenyl-1,1'-diolato) borate [B (OC ₆ H ₄ -C ₆ H ₄ O) ₂ ^- ] and bis (salicylato) borate [B (OC ₆ H ₄ -CO ₂ ) ₂ ^- ];

(K) the boronates

• of the general formula R ^A HBO ₂ ^- , R ^A BO ₂ ^2- and R ^A (R ^B O) BO ^- ;

(L) the carboxylates

• the general formula R ^A CO ₂ ^- ;

(M) the carbonates

• the general formula HCO ₃ ^- , CO ₃ ^2- and (R ^A O) CO ₂ ^- ;

(N) the alkoxides

• the general formula RO ^- ;

(O) and the anions

• Bis (trifluoromethylsulfonyl) imide (NTf ₂ ^- ), bis (pentafluoroethylsulfonyl) imide [(C ₂ F ₅ SO ₂ ) ₂ N ^- ], tricyanomethide [C (CN) ₃ ^- ], tris (trifluoromethylsulfonyl) methide (CTf ₃ ^- ) , Hexafluoroantimonate (SbF ₆ ^- ), hexafluoroarsenate (AsF ₆ ^- ), nitrate (NO ₃ ^- ), nitrite (NO ₂ ^- ), tetrachloroferrate (III) (FeCl ₄ ^- ), tetrabromoferrate (III) (FeBr ₄ ^- ), tetrachloroaluminate (AlCl ₄ ^- ), heptachlorodialuminate (Al ₂ Cl ₇ ^- ), decachlorotrialuminate (Al ₃ Cl ₁₀ ^- ), tetrabromoaluminate (AlBr ₄ ^- ), hexafluorosilicate (SiF ₆ ^2- ) and hexacyanoferrate (III) ([Fe (CN) ₆ ] ^3- )

• • die Reste R^A bis R^D unabhängig voneinander für einen einbindigen, Kohlenstoff enthaltenden und über Kohlenstoff gebundenen, gesättigten oder ungesättigten, linearen oder verzweigten, acyclischen oder cyclischen, aliphatischen, aromatischen oder araliphatischen, unsubstituierten, teilweise oder vollständig halogenierten oder durch 1 bis 5 Heteroatome oder funktionelle Gruppen unterbrochenen oder substituierten Rest mit 1 bis 30 Kohlenstoffatomen;
• • zwei benachbarte Reste aus der Reihe R^A bis R^D zusammen auch für einen zweibindigen, Kohlenstoff enthaltenden und über Kohlenstoff gebundenen, gesättigten oder ungesättigten, linearen oder verzweigten, acyclischen oder cyclischen, aliphatischen, aromatischen oder araliphatischen, unsubstituierten, teilweise oder vollständig halogenierten oder durch 1 bis 5 Heteroatome oder funktionelle Gruppen unterbrochenen oder substituierten Rest mit 1 bis 30 Kohlenstoffatomen.

In the abovementioned general formulas (D) to (N)

• • The radicals R ^A to R ^D independently of one another for a monovalent, carbon-containing and Carbon-bonded, saturated or unsaturated, linear or branched, acyclic or cyclic, aliphatic, aromatic or araliphatic, unsubstituted, partially or completely halogenated or interrupted by 1 to 5 heteroatoms or functional groups radical or having 1 to 30 carbon atoms;
• • two adjacent radicals from the series R ^A to R ^D together also for a divalent, carbon-containing and carbon-bonded, saturated or unsaturated, linear or branched, acyclic or cyclic, aliphatic, aromatic or araliphatic, unsubstituted, partially or completely halogenated or by 1 to 5 heteroatoms or functional groups interrupted or substituted radical having 1 to 30 carbon atoms.

Particularly preferred heteroatoms which may occur in the radicals R ^A to R ^D are oxygen, sulfur, selenium, tellurium, nitrogen, phosphorus and silicon.

For the purposes of the present invention, very particularly preferred anions of the ionic liquids are tetrafluoroborate (BF ₄ ^- ), hexafluorophosphate (PF ₆ ^- ), hexafluoroantimonate (SbF ₆ ^- ), hexafluoroarsenate (AsF ₆ ^- ), methanesulfonate (OMs ^- ), trifluoromethanesulfonate (OTf ^- ), 4-toluenesulfonate (OTs ^- ), acetate (CH ₃ CO ₂ ^- ), trifluoroacetate (CF ₃ CO ₂ ^- ), bis (trifluoromethylsulfonyl) imide (NTf ₂ ^- ), nitrate (NO ₃ ^- ), dihydrogenphosphate (H ₂ PO ₄ ^- ), dimethyl phosphate [(MeO) ₂ PO ₂ ^- ], diethyl phosphate [(EtO) ₂ PO ₂ ^- ], hydrogen sulfate (HSO ₄ ^- ), methylsulfate (MeOSO ₃ ^- ), ethylsulfate (EtOSO ₃ ^- ), thiocyanate (SCN ^- ), dicyanamide [N (CN) ₂ ^- ], tricyanomethide [C (CN) ₃ ^- ], glycolate [HOCH2CO ₂ ^- ], lactate [CH ₃ CH (OH) CO ₂ ^- ].

suitable Metal salts in the sense of the present invention are from cations and anion-built salts in which the cation and / or the Anion contains one or more metal atoms. It can the metal atoms are freely present in the cation, ie simple metal cations of any value, or any number of neutral ones and / or anionic, organic or inorganic ligands of any Teeth are complex. The metal atoms in the anion must be defined by any number of neutral and / or anionic, organic or inorganic ligands of any denticity be complex.

embodiments

Example 1:

AgBF ₄ (0.035 g, 0.179 mmol) and (0.040 g, 0.319 mmol) 1-butyl-imidazole are dissolved in 1-butyl-3-methyl-imidazolium-tetrafluoroborate (2 g) under argon and light-exclusion at room temperature. The resulting solution contains about 1% silver. The solution is transferred under argon into a stainless steel autoclave and dried for 20 minutes in a high vacuum at about 0.1 mbar. The autoclave is then filled directly with hydrogen up to a pressure of 4 bar and the reaction mixture is heated to 85 ° C. for 2 hours. Finally, the stainless steel autoclave is evacuated again and kept at 100 ° C for 1 hour under high vacuum at about 0.1 mbar to remove excess 1-butyl-imidazole from the reaction mixture. The characterization of the silver nanoparticles formed is done in situ by TEM and shows that the reaction is complete. The mean particle size is 2.80 ± 0.78 nm with a minimum size of 1.25 nm and a maximum size of 4.68 nm.

Example 2:

AgPF ₆ (0.010 g, 0.040 mmol) and (0.012 g, 0.096 mmol) 1-butyl-imidazole are dissolved in 1-butyl-3-methyl-imidazolium hexafluorophosphate (2 g) under argon and light at room temperature. The resulting solution contains about 0.15% silver. The solution is transferred under argon into a stainless steel autoclave and dried for 20 minutes in a high vacuum at about 0.1 mbar. The autoclave is then filled directly with hydrogen up to a pressure of 4 bar and the reaction mixture is heated to 85 ° C. for 2 hours. Finally, the stainless steel autoclave is evacuated again and kept at 100 ° C for 1 hour under high vacuum at about 0.1 mbar to remove excess 1-butyl-imidazole from the reaction mixture. The characterization of the silver nanoparticles formed is done in situ by TEM and shows that the reaction is complete. The mean particle size is 4.36 ± 1.25 nm with a minimum size of 2.04 nm and a maximum size of 9.75 nm.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

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Claims (28)

A method for producing and stabilizing functional metal nanoparticles in the particle size range of 0.1 to 1000 nm by reduction of soluble metal salts with hydrogen in ionic liquids, characterized in that the particle size of the resulting metal nanoparticles is adjustable by varying the anion of the ionic liquid used. A process according to claim 1, characterized in that the ionic liquid used is a salt of the general formula [Q ^{n +} ] _m [Z ^m- ] _n composed of cations [Q ^{n +} ] and anions [Z ^m- ] or a mixture of several of these Salts is where n = m or n ≠ m and 1 ≤ n ≤ 4 and 1 ≤ m ≤ 4 and those ionic liquids are particularly preferred in which n = m = 1. A method according to at least one of claims 1 and 2, characterized in that the ionic liquid used has a melting point <180 ° C, preferably <120 ° C and most preferably <100 ° C Has. A method according to at least one of claims 1 to 3, characterized in that by adding a proton scavenger to the reaction mixture a narrow particle size distribution is achieved. A method according to at least one of claims 1 to 4, characterized in that a nitrogen base as a proton scavenger the reaction mixture which, in their protonated form, is similar to a molar volume that of the cation of the used ionic liquid. A method according to at least one of claims 1 to 5, characterized in that it is the nitrogen base used as proton scavenger around the cation of the ionic liquid used underlying nitrogen base. A method according to at least one of claims 1 to 6, characterized in that the reduction with hydrogen in an autoclave at pressures ≤ 5 bar and at temperatures ≤ 120 ° C is performed. A method according to at least one of claims 1 to 7, characterized in that the cation of the ionic liquid used is an imidazolium, Ammonium, pyrrolidinium, piperidinium, pyridinium, morpholinium, Guanidinium, benzotriazolium, quinolinium, isoquinolinium, pyrazolium, 1,4-diazabicyclo [2.2.2] octan-1-ium, 1,2,4-triazolium, pyridazinium, Pyrimidinium, pyrazinium, 1,3,5-triazinium, 1,2,3-triazolium, Piperazinium, oxazolium, oxazolidinium, thiazolium, quinoxalinium, Benzimidazolium, imidazolidinium, indolinium or thiomorpholinium cation is. A method according to any one of claims 1 to 8, characterized in that the anion of the ionic liquid used, a halide, polyhalide, pseudohalide, phosphate, phosphite, phosphonate, phosphinate, sulfate, sulfonate, borate, boronate, carboxylate, carbonate, alkoxide or Bis (trifluoromethylsulfonyl) imide (NTf ₂ ^- ), bis (pentafluoroethylsulfonyl) imide [(C ₂ F ₅ SO ₂ ) ₂ N ^- ], tricyanomethide [C (CN) ₃ ^- ], tris (trifluoromethylsulfonyl) methide (CTf ₃ ^- ) , Hexafluoroantimonate (SbF ₆ ^- ), hexafluoroarsenate (AsF ₆ ^- ), nitrate (NO ₃ ^- ), nitrite (NO ₂ ^- ), tetrachloroferrate (III) (FeCl ₄ ^- ), tetrabromoferrate (III) (FeBr ₄ ^- ), tetrachloroaluminate (AlCl ₄ ^- ), heptachlorodialuminate (Al ₂ Cl ₇ ^- ), decachlorotrialuminate (Al ₃ Cl ₁₀ ^- ), tetrabromoaluminate (AlBr ₄ ^- ), hexafluorosilicate (SiF ₆ ^2- ) or hexacyanoferrate (III) ([Fe (CN) ₆ ] ^3- ). A method according to at least one of claims 1 to 9, characterized in that it is the used ionic liquid to a hydrophobic, water immiscible ionic liquid is. A method according to at least one of claims 1 to 10, characterized in that the ionic liquid used has the same anion like the metal salt used. A method according to at least one of claims 1 to 11, characterized in that the metal nanoparticles produced from the first obtained Metal nanoparticle dispersion can be isolated. A method according to at least one of claims 1 to 12, characterized in that after isolation of the metal nanoparticles, the ionic one used Liquid recovered, cleaned and for more Reactions will be reused. A method according to at least one of claims 1 to 11, characterized in that the initially obtained metal nanoparticle dispersion directly used as active material in catalytic processes. A method according to at least one of claims 1 to 11, characterized in that the initially obtained metal nanoparticle dispersion directly is used as active sensor component. A method according to at least one of claims 1 to 11, characterized in that the initially obtained metal nanoparticle dispersion directly or after a downstream formulation step as antimicrobial Painting or used as a decontamination paint. A method according to at least one of claims 1 to 11, characterized in that the initially obtained metal nanoparticle dispersion with Air, oxygen or other suitable oxidizing agent is treated and thereby metal oxide nanoparticles are obtained. A method according to at least one of claims 1 to 17, characterized in that the nanoparticles produced are silver nanoparticles (Ag) acts. A method according to at least one of claims 1 to 17, characterized in that the nanoparticles produced are copper nanoparticles (Cu). A method according to at least one of claims 1 to 17, characterized in that the nanoparticles produced are cobalt nanoparticles (Co) acts. A method according to at least one of claims 1 to 17, characterized in that the nanoparticles produced are iron nanoparticles (Fe) acts. A method according to at least one of claims 1 to 17, characterized in that the nanoparticles produced are iridium nanoparticles (Ir) acts. A method according to at least one of claims 1 to 17, characterized in that the nanoparticles produced are rhodium nanoparticles (Rh) acts. A method according to at least one of claims 1 to 17, characterized in that the nanoparticles produced are palladium nanoparticles (Pd) acts. A method according to at least one of claims 1 to 17, characterized in that the nanoparticles produced are platinum nanoparticles (Pt) acts. A method according to at least one of claims 1 to 17, characterized in that the nanoparticles produced are gold nanoparticles (Au) acts. A method according to at least one of claims 1 to 17, characterized in that the nanoparticles produced are ruthenium nanoparticles (Ru) acts. A method according to at least one of claims 1 to 17, characterized in that the nanoparticles produced are nickel (Ni), zinc (Zn), cadmium (Cd), manganese (Mn), rhenium (Re), chromium (Cr), molybdenum (Mo), tungsten (W), vanadium (V), niobium (Nb), tantalum (Ta), titanium (Ti), zirconium (Zr), hafnium (Hf), scandium (Sc) or yttrium nanoparticles (Y) acts.