CH634176A5 - Dye based on at least one laser dye molecule - Google Patents

Abstract

The dye, based on at least one laser dye molecule, has at least one fluorescence dye molecule residue whose fluorescence region overlaps as much as possible with the absorption region of the laser dye molecule residue and which is linked to the laser dye molecule residue directly or via bridging elements of at most 20 ANGSTROM length in such a manner that the pi -electron systems of the individual laser dye and fluorescence dye molecule residues do not form any conjugation system which is capable of joint mesomerism (structural resonance). This dye has a high efficiency and a long useful life when used in dye lasers.

Description

       

  
 

** WARNING ** beginning of DESC field could overlap end of CLMS **.

 Forming molecule is linked to a common anchor molecule.



   14. The method according to claim 13, characterized in that the anchor molecule consists of an aromatic hydrocarbon, a heterocycle or a high polymer.



   The invention relates to new dyes and processes for their production, namely new dyes which have a significantly higher efficiency and a significantly higher service life when used in dye lasers.



   Of the laser dyes usually used, only a small fraction of the white excitation light of the xenon flash lamps, which are mostly used as an excitation light source, can be used, namely predominantly that which is absorbed by the narrow, long-wave absorption band of the dye molecule.

  Since the half-widths of the absorption band of the customary laser dyes are typically 5000 cm -1, the emission spectrum of the xenon flash lamps from the permeability limit of the quartz glass bulb at about 200 nm (= 50,000 cm-1) to above the absorption limit of the long-wave absorbing dyes at about 1 ", lm (= 10,000 cm-1 is sufficient, i.e. it comprises 40,000 cm-1, typically only about one eighth of the available power of the exciting xenon flash lamps can be used.

  In fact, the fraction used is usually still much lower, since the energy emitted by the xenon flash lamps is not evenly distributed over the entire spectrum, but rather increases significantly after short wavelengths, and the more so, the shorter the rate at which the current pulse rises Flash lamp and the higher the current density in it. Since both the current rise rate and the current density are chosen to be as high as possible in the customary dye lasers for reasons well known to the person skilled in the art, usually only about a tenth of the incident light can be absorbed and converted into laser radiation.

  This and the losses in the conversion of electrical to optical energy in the flash lamp result in a maximum efficiency (= laser energy / electrical pulse energy) of only 1.5% for the best dye lasers in existence today. A more detailed description of these conditions can be found at F.P. Schäfer: Principles of Dye Laser Operation in: Dye Lasers, F.P. Schäfer, Ed., Springer Verlag, Berlin, Heidelberg, New York, 1973. It is therefore an object of the present invention to provide dyes and processes for their production which utilize as much of the excitation light as possible and thereby achieve a higher efficiency of the dye laser .

  Another goal is the creation of dyes, which make it possible not only to operate dye lasers in pulse mode with xenon flash lamps, but also using continuously burning, incoherent light sources with an essentially white spectrum, such as high-pressure xenon lamps, metal halide lamps or the sun, for example Intensity when using conventional dyes is not sufficient for the continuous operation of dye lasers.



   Another object of the invention is to increase the useful life of laser dyes. It is known that all laser dyes are destroyed more or less quickly photochemically, which is essentially caused by the ultraviolet component of the excitation light. For example, the useful life of a solution of Rhodamine 6G in a dye laser from L. Ringwelski and F. P. Schäfer (F. P. Schäfer, Liquid Lasers, in Laser Handbook, F. T. Arecchi and E. O.



  Schulz-Du Bois, Eds., North Holland, Amsterdam, 1972, p. 404) can be increased tenfold by filtering out the ultraviolet portion of the excitation light using a 0.75 molar copper sulfate solution.



   Finally, it is an object of the invention to provide new dyes for textiles, leather and the like, and pigment dyes for paints, varnishes, printing inks and the like. Ä. To create that have superior lightfastness.



   Attempts have been made to make better use of the excitation light spectrally by using mixtures of the laser dye with shorter-wave absorbing, well-fluorescent dyes instead of a single laser dye, the fluorescence of the added dye being partially absorbed by the laser dye and thereby effectively increasing the excitation power in the laser dye was (GB-PS 1 255 399). However, the increases in the output powers of the dye laser given there after the addition of the fluorescent dye are not a measure of the better utilization of the excitation light, but rather a purely arbitrary, manipulable measure, as can be shown by the following consideration. In Example 3 or above.

  GB-PS is used in a dye laser acridine red as a laser dye with a concentration of 10-4 M and a certain laser energy is measured at a capacitor voltage of 15 kV. Rhodamine 6G is then added as the fluorescent dye until the solution is 10-4 with respect to both dyes, and an increase in the laser energy by a factor of 9.5 is measured.



  If one were to lower the capacitor voltage so far that one would stay just below the threshold of the laser emission with the pure acridine red solution, and then use the mixture at the same voltage, one would measure a certain output energy, now because of the additional fluorescence of the rhodamine, the increase in the excitation power of the acridine red would exceed the laser threshold, which meant an increase in the output power by the factor infinity. By adjusting the capacitor voltage between the threshold value for the laser emission and 15 kV, each factor between infinity and 9.5 can now be achieved, as can the factor below 9.5 by further increasing the capacitor voltage. A significantly better measurement number for the improvement of the efficiency is from W. Schmidt, W. Appt and N.

  Wittekindt, Z. Naturforsch. A27 (1972) 37. The electrical pulse energy at which a certain laser energy is achieved with the laser dye alone is measured, and the mixture is then used to determine the electrical pulse energy at which the same laser power is achieved as with the laser dye alone.



  The ratio of the two electrical energies is a very good measure for the improvement achieved in the utilization of the excitation light spectrum. The latter authors found loc. cit. that in their cresyl violet dye laser the excitation energy to obtain 10 kW laser power was reduced by a factor of two when an optimal amount of rhodamine 6G was added as the fluorescent dye to the solution, and that with a laser power of 25 kW this factor was 2 , 7 was.

 

   However, the known method described above of improving the laser efficiency by mixing fluorescent and laser dyes has serious disadvantages. This is usually the case with the concentrations which are usually used in dye lasers excited with flash lamps <10-4 M, the energy transfer from fluorescent dyes to the laser dye is by no means complete. A large part of the fluorescent light emitted isotropically in all directions is lost through the cuvette walls instead of being usefully reabsorbed by the laser dye molecules as long as the energy transfer is radiating. However, the energy transfer from the fluores



  zenzfarbstoff (donor) to the laser dye (acceptor) also radiation-free. The probability of this can be calculated according to the theory by Th. Förster, Fluorescence of Organic Compounds, Göttingen, 1951, p. 83. The characteristic distance Ro between donor and acceptor molecules, at which the probability of non-radiative energy transfer is 50%, is of the order of magnitude 100 with good spectral overlap of the fluorescence band of the donor molecule with the absorption band of the acceptor molecule, while the average molecule distance at the concentration given is about 200 A. is.

  An almost complete radiation-free energy transfer can only be achieved at the very high concentrations that are required when exciting a dye laser with the aid of nitrogen lasers or other lasers, which is described by 1. B. Berlman, M. Rokni and CR Goldschmidt, Chem. Phys . Lett. 22 (1973) 458, but was of no importance for the task of excitation of the laser with incoherent, white light sources.



   A much more serious disadvantage, however, can be seen in the fact that the excited donor molecules often have new absorption bands in the excited state, which are precisely in the spectral range of the laser emission and thus reabsorb the laser light and thus reduce the laser power or even completely suppress the laser emission.



  Such examples are by W. Schmidt et al., Loc. cit., cited and by A. Hirth, These, Strasbourg, 1974, p.90, where the laser dye hexamethylindotricarbocyanin after addition of various fluorescent dyes, such as rhodamine 6G, cresyl violet, diethyloxatricarbocyanine or Oxazin 1 from Eastman Kodak, always shows a reduction the laser energy was found with respect to the sole use of the laser dye. Hirth was able to demonstrate that this reduction in laser energy was caused by new absorption bands of the excited fluorescent dyes, in which he used a double-walled cuvette, in the inner vessel of which the laser dye and in the outer concentric jacket vessel one of the above. Fluorescent dyes.

  In these cases, there was an increase in the laser energy each time, since the fluorescent radiation emitted by the fluorescent dye was at least partially absorbed by the inner cuvette with the dye solution and thus increased its excitation energy without absorption in the laser beam running along the cuvette axis and filling the inner cuvette was introduced. The increase in laser energy was only modest (about 50%), since the majority of the fluorescent light from the outer jacket cell passed the cell uselessly.



   The disadvantages described above are completely or at least partially overcome by the invention.



   The invention relates to dyes based on at least one laser dye molecule, which are characterized in that they have at least one fluorescent dye molecule residue, the fluorescence area of which overlaps as far as possible with the absorption area of the laser dye molecule residue and which directly or via a bridge member of at most 20 Å in length what is linked is that the n-electron systems of the individual laser dye or fluorescent dye molecule residues do not form a conjugation system which is capable of mesomerization together.



   This linkage can consist of mesomerically inactive bridge members (e.g. - (CH2) groups of at most 20 A in length, spiroatoms or linkage via aromatics at mesomerically or largely inactive sites, such as benzene derivatives in a meta position to one another.



   Furthermore, the subunits can also be linked directly to one another, but can be twisted strongly against one another by suitably arranged, sufficiently voluminous substituents and prevented from forming a coplanar overall system.



   The inventive solution to the problem of creating new laser dyes with higher efficiency and longer service life and methods for their production is based initially on known dyes. The term dye is used here in a broader sense, meaning all substances with conjugated double bonds, which includes the dyes in the narrower sense, namely absorbent substances in the visible.

  First, a laser dye L is selected which emits in the desired wavelength range. In the context of the present invention, a laser dye is defined as a dye in a broader sense (i.e. light absorption by excitation of an n-electron), which has a sufficient quantum yield, i. H. has more than 0.5 of the fluorescence and its singlet-singlet absorption (Sl-Sn) is smaller than the stimulated fluorescence emission cross section. A fluorescent dye F1 is then selected, the fluorescent band of which should coincide as well as possible with the absorption band of the laser dye. Further criteria for selecting a suitable fluorescent dye are explained below.

  Now further fluorescent dyes Fz, F3, F4 etc. can be selected, which can be the same or different, in such a way that the absorption band of the dye with the smaller index and the fluorescence band of the dye with a higher index overlap as well as possible. These dyes selected in this way are now linked according to the invention either directly or via bridging links by chemical bonds in such a way that the spatial distance between the dyes' connecting points is at most about 20 Å, but the dyes are linked such that the electron systems of the adjacent dyes are decoupled and thus there are no significant changes in the absorption spectra compared to the unbound dyes.

  In other words, no mesomerism should occur between the mesomeric systems of the individual dye molecules. As the person skilled in the art will readily recognize, this chemical linking of the dyes can be carried out by methods which are all known per se to the person skilled in the art and some of which are to be listed below by way of example. Using the examples given, the person skilled in the art can work out further analogous linking methods.

  The person skilled in the art will also immediately recognize that, from case to case, one starts either from the dye molecules to be linked themselves, from these the first one is reacted with one end group of a linking molecule, and then the other end group thereof is reacted with the second dye molecule; or in other cases not from the unchanged dyes, but from unsubstituted or substituted with suitable, reactive groups dye derivatives or precursors which form the desired dye in the linking reaction (or the linking reactions).

 

   Already with the chemically simple linear linkage through two methylene groups, there are many possibilities of linkage, for example, the new laser dyes can be constructed according to the following scheme:
L-CH2-CH2-Ft, L-CH2-CH2-Fl-CH2-CH2-F2, L-CH2-CH2-Fi-CH2-CH2-F2-CH2-CH2-F3, and so on; or Fl-CHz-CH2-L-CH2-CH2-F2 or Fl-CH2-CH2-F2-CH2-CH2-L
EMI4.1
 and other combinations according to these examples.



  Instead of the i.a. Linking via two methylene groups, which is particularly simple to carry out, can of course also be linked via one or more than two methylene groups. Furthermore, the CH2 groups can also be replaced by CHR or CRIR2 groups, but also by -CH2-O-CH2 or CHz-N (R) -CH2 or CHz-S-CH1-G groups.



   According to a preferred embodiment of the invention, a dye molecule therefore has the general formula
X (CR1R2) n X [(CR1R2) n X] m, where n is 0 or an integer from 1 to the number corresponding to a chain length of 20 Å, m is 0, 1, 2 or 3, X is a laser dye residue L or Fluorescent dye residue F and Rl and R2 independently of one another can each represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, with the proviso that one of the groups X represents a residue L, all residues F can be the same or different and the bridge members CRtR2 also by Oxygen, nitrogen or sulfur atoms can be connected to one another.

  If the groups - (CRIR2) n - are only alkylene groups, then n can be a number from 1 to 13.



   Another type of linkage is to link three dyes via a tertiary carbon atom, if the steric conditions permit. Examples here are:
EMI4.2
 and corresponding other variations. They have the general formula HC [(CH2) n X] 3, in which the definition given above applies to n and X.



   As a further type of linkage, one or more quaternary carbon atoms, for example in a spiro or allene system, is possible in accordance with the examples
EMI4.3
 Another way of linking is by the type of cyclophane:
EMI4.4
  
EMI5.1


 <tb> or
 <tb> <SEP> F
 <tb> <SEP> · <SEP> M
 <tb> <SEP> (ctI2) n1 <SEP> (Cll2) 1
 <tb> H-C <SEP> - <SEP> L-C-H
 <tb> <SEP> (ClI2) n1 <SEP>) <SEP> 1 <SEP> (CIH2) n1
 <tb> H-C <SEP> - <SEP> F2C-H
 <tb> <SEP> (CH2 <SEP>) <SEP> n1 <SEP> (CH2 <SEP>) <SEP> n1
 <tb> <SEP> and <SEP> like this <SEP> further.
 <tb> <SEP> F3 <SEP> Here <SEP> means <SEP> nl <SEP> one <SEP> whole
 <tb> <SEP> number <SEP> from <SEP> 1 <SEP> to <SEP> 13, <SEP> preferably
 <tb> <SEP> from <SEP> 1 <SEP> to <SEP> 4.
 <tb>



   In this way it is also possible to construct annular or network-like arrangements and layer-like arrangements by means of cross-connections.



   Furthermore, the dye residues X can also be side groups of ring compounds, it being possible for them to be arranged on the ring both in the adjacent position and at a distance from one another. The following formula shows an example:
EMI5.2
 Such dyes according to the invention linked via an alicyclic or heterocyclic ring system can, for. B.



  by 1,3-dipolar addition or by Diels-Adler or other cycloadditions.



   Heteroatoms can also be inserted into the bridges or used as bridges, e.g. B. an ether bridge:
Fl-CH2-O-CH2-L-CH2-O-F2 and so on.



   Furthermore, two dyes without bridging atoms can also be directly linked to one another without this having any significant influence on the it electron systems, either by virtue of their structure peculiarities or by adding sufficient space-filling substituents to at least one of the dyes to ensure that the levels of the Dyes are approximately perpendicular to each other.



   The dyes can also be linked via unsaturated or aromatic or heterocyclic groupings if the above-mentioned, necessary for the isolation of the chormophroe, e.g. B. steric, conditions are met. This also includes a mesomerically largely indifferent linkage via an aromatic, such as, for example, by meta linkage via a benzene ring according to the following general formula:
EMI5.3
 in which X has the above meaning.



   The linking of the dyes, if they each carry at least one hydroxyl or amino group, is also possible via molecules such as cyanuric chloride or other anchor compounds that can be used for the construction of reactive dyes, for example according to the general formulas
EMI5.4
 Numerous methods are available to the person skilled in the art for producing the novel dyes according to the invention.



  The linking of the different dye residues X is particularly simple with the help of bridging compounds with two reactive groups, which can establish the link with the dye residues. Suitable bridging compounds are, for example, diols, dialdehydes, dicarboxylic acids and their reactive derivatives such as esters, acid chlorides, acid azides, isocyanates and the like, diepoxides, diamines and the like. These bridge-forming compounds can be reacted with corresponding reactive groups in the individual dye molecules in a manner known per se, for example with carboxyl groups and their derivatives, amino groups, hydroxyl groups, keto groups, aldehyde groups and the like.



  All of these reactions are well known to the person skilled in the art and need not be described in more detail here (E. Siegel: Reactive dyes: reactive groups in K. Venkataraman, The Chemistry of Synthetic dyes, Vol. 6 (1972) pp. 1-209; further: Coons , J. Immunology 45 (1942) 159, Riggs, Americ. J. Pathol. 34 (1958) 1081).

 

   Typical examples of the above-mentioned reactions are the reaction of a carboxyl group or activated carboxyl group, which is located on a dye molecule, with a diol to form the corresponding half-ester, which is then reacted with a second dye molecule to give the dye according to the invention. This reaction can be carried out, for example, in the presence of a strong acid in an immiscible organic medium, such as a halogenated hydrocarbon. Suitable strong acids are, for example, sulfonic acids, such as toluenesulfonic acid or polymers carrying sulfonic acid groups.



   Another way of linking the carboxyl group to a hydroxyl group is to react in the presence of an alcoholate.



   If the dye residue to be incorporated into the dye according to the invention does not contain any reactive substituents but does contain aromatic ring systems, a link according to the methods of aromatic substitution is appropriate. For example, phenyl radicals can be substituted with activated acid derivatives, such as acid anhydrides or acid chlorides in the presence of aluminum chloride, in a suitable organic medium. The ketones formed here can then in turn be reduced in a known manner with removal of the oxygen atom, for example with hydrazine hydrate in a strongly alkaline medium.



     A further possibility of linking dye residues X which have a hydroxyl or amine group consists in the reaction with cyanuric chloride to form an s-triazine, for example according to the scheme below:
EMI6.1
 Another way of linking is that each of the dyes Fl .2 .... and L is provided with a reactive group R.

  These dyes are then combined with a suitable polyalcohol, polyphenol or polyamine (or also with mixed amino alcohols) to form a dye according to the invention, for example with the following structure:
EMI6.2
 Of course, two or more of the specified types of linkage can be combined with one another if this should make sense under the circumstances prevailing in the individual case, in particular taking into account the chemical properties of the dyes to be linked.



   Accordingly, a method according to the invention for producing the new dyes described above consists in the fact that a) an i. a. a reactive group carrying first laser dye or fluorescent dye with a bridging compound, the molecular length of which does not significantly exceed 20 A and which has at least two reactive groups, at least one of which is able to form a covalent bond with the first dye, is reacted in equimolar amounts and the reaction product with its second reactive group is reacted with a second dye, which is different from the first dye, one of the dyes being a laser dye and, if appropriate, the product being reacted one or more times with another bridging molecule and another fluorescent dye,

   or b) an aromatic ring system is reacted in succession under the conditions of metasubstitution with at least one fluorescent dye and a laser dye, which carry substitutable groups, such as activated acid residues, or c) a laser dye and at least one fluorescent dye, which with a suitable anchor molecule, such as Cyanuric halide, are reacted, or d) a laser dye and at least one fluorescent dye are directly linked to one another by the customary methods for preparing corresponding aromatic compounds, the formation of a common conjugated system being prevented by sufficiently voluminous substitutes, or e) a laser dye and at least one Fluorescent dye are each connected to a bifunctional bridging molecule,

   the second reactive group of the bridging molecule is then linked to a common anchor molecule, which can be an aromatic hydrocarbon, a heterocycle or a high polymer.



   With the new dyes there is occasionally the difficulty that the solubility in water or alcohol, the most commonly used solvent for laser dyes, becomes too low due to the molecular size. This difficulty can be avoided by introducing solubility-increasing groups into the molecular structure at a suitable point in a manner known per se, e.g. B. sulfonate groups or quaternary amino or alkylamino groups to increase the solubility in water and / or linear or branched alkyl groups and / or tertiary alkylamino groups to increase the solubility in alcohol.



   The superior suitability of the dyes described above as laser dyes is based on the fact that within the
A radiation-free energy transition takes place from the fluorescent dye residues Fi (i = 1, 2, 3 ...) to the laser dye residue L, in such a way that, in accordance with the overlap of the respective absorption and fluorescence spectra in the manner described above, the energy transfer to
Laser dye is carried out directly or in several steps from one fluorescent dye to another and finally to the laser dye.

  Since the distance between the fluorescence and laser dye residues is less than 20 Å according to the invention, the radiation-free energy transfer is practically complete, which can be calculated quantitatively as follows. The transition frequency k for the radiation-free energy transition from the donor to the acceptor molecule, here in this case for example from F1 to L or from Fi to Fi-1, is according to
Förster theory given by k = 1 / TF (Ro / R) where TF is the
Fluorescence decay time of the donor molecule in infinite
Removal of acceptor molecule means R the distance between donor and acceptor molecule and Ro a characteristic distance,

   where the probability of the energy transfer is 50% and that is
Spectra of donor and acceptor molecule can be calculated and is in the order of 100 A for most of the dyes in question. In order to calculate the order of magnitude of k, the largest possible distance according to the invention of the linking sites of donor and acceptor molecule is used for R, that is R = 20 A: Then k = llTF (1O012O) 6 = 15625 / in. This means that the About frequency of the radiationless energy transfer from
Donor- to the acceptor molecule is more than 104 times larger than that of the deactivation of the excited donor molecule by spontaneous fluorescence emission, 1 / TF.

  As a result, the transition of excitation energy from the donor to the
Acceptor molecule practically complete, since less than every ten thousandth donor molecule emits spontaneously instead of transferring its energy to the acceptor molecule. If the spatial distance between the donor and acceptor is significantly smaller than 20 Å, the transition frequency k assumes values that are still much larger. According to Förster's theory, the Ro values given relate to a mean value for statistically oriented donor and acceptor molecules, while here i. a. there is a spatial fixation to each other. For all possible orientations, a precise consideration only brings about a correction factor of the order of 1.



   In the dyes according to the invention is therefore due to
Favoring the energy migration, the photochemical effect of the light, without the need for an external filter, is reduced to an insignificant fraction and thus theirs
Service life significantly increased.



   It is particularly noteworthy that the energy transfer, since it takes place here in an innermolecular manner, remains effective even in the case of very dilute solutions, as are required for large-volume dye lasers, in contrast to the non-radiative energy transfer in dye mixtures as has been used up to now .



   Another advantageous effect of the intramolecular radiation-free energy transfer in the new dyes is due to the shortening of the lifespan of the excited
Condition of the donor. While the lifetime X of the excited singlet state of the isolated donor molecule (ie in a good approximation in solutions with concentrations less than 2 1 10-4 M) is equal to the fluorescence decay time TF, X is shortened according to 1 / T = 11 TF + by the radiationless energy transition k. According to the above estimate, T <10-4- Tr.

  However, since the probability of absorption of an excitation light quantum or (which is even more significant because of the losses caused thereby) of a laser light quantum by an excited donor molecule is proportional to the lifetime of its excited state, the losses due to reabsorption of the excitation and / or laser light in the new laser dye are compared with mixtures of the corresponding dyes to be reduced by at least a factor of 104.

  In fact, this factor is much higher, since the number of long-lived triplet states with the particularly high probability of absorption due to their long lifespan of typically more than 10-7 seconds is also reduced by at least a factor of 104, since the number of triplets generated is also proportional to the lifespan of the excited state.



   From the explanations about the shortening of the lifespan of the excited state by means of radiation-free energy transfer, it can also be seen immediately that even practically non-fluorescent donor molecules can be used, since the radiation-free deactivation processes competing with the radiation-free energy transition even with fluorescence quantum yields of 10-4 (i.e. with non-fluorescent dyes ) are slower than the radiationless energy transfer. This is experimental by D. Möbius and G. Dreizler, Photochem. Photobiol. 17 (1973) 225 using the example of non-fluorescent azo dyes as donor molecules and cyanine dyes as acceptor molecules has also already been detected.

  Nevertheless, one will advantageously select as donor dyes those with at least moderate fluorescence quantum yields (approximately> 1%) in order to suppress the competing radiationless deactivation processes as much as possible, since they mean one, if only slight, loss of excitation energy.



   The increase in the useful life of the new dyes that can be achieved according to the invention when used as laser dyes results from the fact that in the immediate vicinity of the laser dye residue there is a shorter-wave radiation-absorbing fluorescent dye residue which serves as a protective filter for the laser dye residue. This protective effect becomes stronger the more fluorescent dye residues in the same molecule are linked to the laser dye residue in the manner described above. One could now expect that the donor molecules absorbing the ultraviolet light may then be destroyed photochemically and thus lose their protective effect.

  However, it was found that the donor molecules are largely protected against photochemical destruction by the shortened lifetime of the excited state due to the radiationless energy transfer to the acceptor molecules.



   Another favorable property of the new dyes is achieved if one of the fluorescent dye residues linked to the laser dye residue has a triplet level which is lower in energy than the triplet level of the laser dye residue, and if this fluorescent dye residue is linked to the laser dye residue in such a way that the spatial distance of the linking points only a few ng of current (up to approx. 8). In addition, the said fluorescent dye residue must have no or at most a small triplet triplet absorption in the region of the laser wavelength. This then has the following effect: The fluorescent dye residue in question absorbs excitation light and transmits its excitation energy to the laser dye residue either directly or via one or more stages without radiation.

  The water now either stimulates or spontaneously emits a light quantum or is deactivated by radiation-free processes.



   There is a certain likelihood that the said laser dye residue will change to the triplet state, which would cause severe reabsorption losses with its long service life in the manner described above. However, due to the proximity of the fluorescent dye residue, there is a high probability that a radiation-free energy transition to its lower triplet level will be brought about.



   In this way, the triplet state of the laser dye is quickly removed without additional triplet extinguishers such. As oxygen or cyclooctatetraene, must be added, which in most cases still show undesirable chemical side effects.



   Finally, it should be mentioned that those described here
Dyes can of course also be advantageous for other applications, for example as textiles; Leather or as pigment dyes, e.g. for paints, paints or printing inks. Through the links described here, particularly lightfast textile dyes, for. B. greenish
Black and a. represent more that are difficult, if at all, to be obtained by other means, for example by dye mixtures or by re-dyeing with one or more dyes.

  According to the above, it is a simple task for a person skilled in the art to adapt the properties of the new dyes to the respective application by means of appropriate substitutions and selection of the dyes to be linked, for example the drawing properties on different textile fibers, etc.
Examples
In the following, synthetic routes for three of the new laser dyes are given and for each example further dye combinations are mentioned which can be linked in this way in order to obtain new laser dyes.



  Example 1: Rhodamine K1
The new dye, known as Rhodamine Kt, is created by linking Rhodamine 6G and Rhodamine B in each of the following ways:
EMI8.1


 <tb> <SEP> Et <SEP> 0 <SEP> NH <SEP> Et
 <tb> <SEP> 0
 <tb> rhodamine <SEP> 6G <SEP> XCOO et <SEP> + <SEP> HOCH2CH2CH2CH2OH
 <tb> <SEP> 0 <SEP> COO Et <SEP> butanediol <SEP> 11.4)
 <tb> <SEP> I3utanediol <SEP> (1.4)
 <tb> <SEP> 76
 <tb> Et'HN <SEP> eµ, O
 <tb> <SEP> 0 <SEP> 0OO-CH2-CH2-CH2-CH2-OH
 <tb> <SEP> rhodamine <SEP> 6G-butanediol <SEP> (1.4)
 <tb> <SEP> half-way
 <tb> <SEP> rhodamine <SEP> B
 <tb> <SEP> HOOC
 <tb> <SEP> +
 <tb> <SEP> 0
 <tb> <SEP> N / Et
 <tb> <SEP> Et <SEP> Et
 <tb>
EMI9.1


 <tb> <SEP> 34 <SEP>% 1
 <tb> EtH <SEP> O, <SEP> H <SEP> Et <SEP> ns
 <tb> <SEP> iN <SEP> N
 <tb> <SEP> rhodamine <SEP> class <SEP> Et <SEP> o <SEP> 52 <SEP> 4 <SEP> o <SEP> &commat;

   <> <SEP> N \ / Et
 <tb> <SEP> Et / N <SEP> &commat; <SEP> Et
 <tb> A. Rhodamine 6G-butanediol (1,4) half ester
44 g of rhodamine 6G (0.1 mol) and 27 g of butanediol (1.4) (0.3 mol) are heated to about 100 ° C. with about 3 g of sodium methyl alcoholate under a water jet vacuum until no more ethanol is distilled off. With cooling is neutralized with 10% hydrochloric acid until the half ester of the base separates, it is filtered off with suction, washed with a little cold water and dried. Yield 35.5 g = 76%.



  B. Rhodamine 6G-Rhodamine B-butanediol (1,4) diester = Rhodamine K1
With careful cooling, 11.6 g of rhodamine B (0.03 mol) are mixed with 6 g of concentrated sulfuric acid, and 30 g of the butanediol (1,4) half-ester of rhodamine 6G (0.06 mol) are introduced therein. After standing for 2 hours at room temperature, the mixture is heated at 80 ° C. for one hour in order to then pour the solution into 600 ml of ice water. After about 10 hours, the mass has crystallized; the mixture of sulfates is filtered off, dissolved in water and neutralized with sodium carbonate solution.



  Unreacted rhodamine-6G acid and rhodamine B are filtered off; the filtered solution is carefully salted out with concentrated NaCl solution, the hydrochloric acid salt of the diester separating out. Yield 9.1 g = 34%.



   Analogous linkages were also carried out with the following dye pairs: Rhodamine 6G + Rhodamine S Rhodamine 6G + Pyronine Rhodamine S + 2,7-dichlorofluorescein Example 2: Fluorescein K1
The dye, called fluorescein K1, is created by linking each fluorescein with 2,7-dichlorofluorescein in the following way:
EMI9.2


 <tb> <SEP> HO
 <tb> F1uoreseein% OH <SEP> + <SEP> HO-CH2-CH2-CH2-CH2-OH
 <tb> <SEP>; butanediol- (1.4)
 <tb> <SEP> 77 <SEP> o /
 <tb> <SEP> 77%
 <tb> <SEP> \ <SEP>,
 <tb> <SEP> HO <SEP> F1uoresceinbandio1- <SEP> (1.4)
 <tb> <SEP> &hbar;

   <SEP> l <SEP> l <SEP> fluorescein-butanediol- (1.4)
 <tb> <SEP> half-way
 <tb> <SEP> 0 <SEP> CO-O-0H2-CH2-CH2-CH2-OH
 <tb>
EMI10.1


 <tb> <SEP> 0
 <tb> <SEP> + <SEP> HOOC
 <tb> <SEP> ct
 <tb> <SEP> 0 <SEP> ct
 <tb> <SEP> HO <SEP> O <SEP>
 <tb> <SEP> 2,7-dichlorofluorescein
 <tb> <SEP> 47 <SEP>% 1
 <tb> HO <SEP> 0
 <tb> <SEP> CO-O <SEP> -CH <SEP> 2-CH2-CH2-CHa-O-OC (
 <tb> <SEP> v <SEP> Cl <SEP>> S + Ct <SEP>
 <tb> <SEP> fluorescein <SEP> K1 <SEP> where <SEP> O <SEP> ici
 <tb> A. Fluorescein-butanediol41,4) half-ester
33.2 g of fluorescein (0.1 mol) are mixed with 50 g of butanediol <1.4) (0.6 mol), 2 g of toluenesulfonic acid and 100 ml of CCl4 are added and the mixture is boiled on a water separator (8 hours) until no more water is separated off.

  Most of the unreacted alcohol and CCl4 are distilled off; the precipitated product is washed several times with water, aqueous Bicar bonat solution and again with water. The red half ester is suctioned off and washed with water, then with cold ethanol. The crude product is recrystallized from acetone. Yield 31 g = 77%.



  B. Fluorescein-2,7-dichlorofluorescein-butanediol <1,4ydiester =
Fluorescein K1
12.3 g of 2,7-dichlorofluorescein (0.02 mol) are mixed with 24.2 g of fluorescein-butanediol (1, 4-half-ester (0.06 mol) and 3 g of toluenesulfonic acid in 300 ml of glycol diethyl ether in a circulation apparatus with a separate desiccant (P20s ) Boiled for 15 hours, then the majority of the solvent is distilled off, washed with water, aqueous bicarbonate solution and again with water, the solid reaction products are suctioned off, washed with warm water and then with ethanol
Crude product is recrystallized twice from n-butyl acetate. Yield 7.4 g = 47%.



  Example 3: Terphenyl K1
The laser dye called Terphenyl K1 is created by linking one molecule of 9.1 0-diphenylanthracene and terphenyl in the following way:
EMI11.1


 <tb> <SEP> 0
 <tb> <SEP> o
 <tb> <SEP> + <SEP>) LCH2 <SEP> ¯¯¯¯¯¯
 <tb> <SEP> o
 <tb> <SEP> + o
 <tb> <SEP> terphenyl <SEP> 0
 <tb> <SEP> 0
 <tb> 71 <SEP> O / o <SEP> II
 <tb> <SEP> 10 <SEP> C - CH2- <SEP> CH2- <SEP> COOH
 <tb> 4- (4-terphenyl) -4-oxobutyric acid
EMI11.2

EMI11.3


 <tb> <SEP> 0
 <tb> <SEP> 0 <SEP> 0
 <tb> <SEP> t <SEP> + <SEP> Ct-C11-CH2-CH2-C11
 <tb> <SEP> 63 <SEP>%
 <tb> 9,10-diphenylanthracene <SEP> <SEP> t
 <tb> <SEP> Oo
 <tb> <SEP> II <SEP> II
 <tb> <SEP> t <SEP> CH2CH2C <SEP> m
 <tb> <SEP> 1-4 '- (9, <SEP> 10-diphenyl
 <tb> <SEP> F;

  ;.? <SEP> OI- <SEP> anthrac <SEP> erryl <SEP>) -I <SEP> - <SEP> 4- <SEP> ( <SEP> 4- <SEP> t <SEP> erphenyl <SEP>)
 <tb> <SEP> W <SEP> 63 <SEP> O / o <SEP> aifl, t4hrauCtaeflnYlio) = W <SEP> -4- <SEP> 4-butanedione
 <tb>
EMI12.1


 <tb> <SEP> 0 <SEP> CH2-CH2-CH2CH2 <SEP> M · ¸
 <tb> C <SEP> X, CH2CH2CH2CH2 <SEP> <
 <tb> <SEP> -erphenyl <SEP> E1
 <tb> A. 444-Terphenyl4-oxo-butyric acid
45 g of AlCl3 (0.4 mol) and 10 g of succinic anhydride (0.1 mol) are suspended in 100 ml of carbon disulfide. After cooling the mixture with ice water, a suspension of 23 g of terphenyl (0.1 mol) in 50 ml of carbon disulfide is gradually added over an hour. With stirring, the mixture is allowed to warm to room temperature until the HC1 evolution comes to an end.

  The mixture is left to stand for 3 hours, then the reaction product is poured onto a mixture of ice and concentrated hydrochloric acid. The remaining solid residue is filtered off and washed with water. It is dissolved in hot, concentrated sodium carbonate solution, filtered and the filtrate is acidified with semi-concentrated hydrochloric acid, the 4- (4-terphenyl) 4-oxo-butyric acid precipitating. Yield 23 g = 71%.



   One equivalent of the acid is now converted into the acid chloride with 1.5 equivalents of thionyl chloride; Excess thionyl chloride is removed in vacuo. Yield 22 g = 87%.



  B. 1 {4B- (9,10-Diphenylanthracenyl) -] 4- (4-terphenyl) -1,4-butanedione
In 100 ml of thrichlorethylene, 45 g of AlCl3 (0.4 mol) and
19 g of the acid chloride of 4- (4-terphenyl) 4-oxo-butyric acid (0.05 mol) suspended; the suspension is cooled with ice and then a suspension of 16.5 g of 9,10-diphenylanthracene (0.05 mol) is gradually added, the temperature not to rise above 20 ° C. Stirring is continued for an hour, then the mixture is left to stir The mixture is then poured onto about 600 g of ice, to which concentrated hydrochloric acid is added, the trichlorethylene phase is separated off and the water layer is shaken out three times with trichlorethylene.

  The organic phase is washed with water, 2% NaOH and again with water; it is dried with potassium carbonate, then the solvent is distilled off. The resulting diketone li2- (9,10-diphenylanthracenyl) -4-terphe 1,4-butanediol is recrystallized from O-dichlorobenzene. Yield 20.2 g = 63%.



  C. 1 {4'A9,10-diphenylanthracenyl>] 444-terphenylfbutane = terphenyl K1
18 g of the diketone described above (0.03 mol) are boiled under reflux with 8 g of 85% hydrazine hydrate solution (0.2 mol) and 14 g of finely powdered potassium hydroxide (0.25 mol) in 50 ml of triglycol. A mixture of hydrazine and water is then slowly distilled off until the temperature of the reaction mixture is 195 ° C. This is maintained until the evolution of nitrogen has ended. After cooling, the mixture is diluted with water and the hydrocarbon is etherified he recrystallized from ligroin. Yield 11.6 g = 63%.

 

   Analogous linkages were carried out for the following dye pairs: 9.1 0-diphenylanthracene + 4-methoxy-terphenyl, 9,10-diphenylanthracene + quaterphenyl, pyrene + terphenyl, fluorene + 4,4-bis (alkyloxy) -p-quaterphenyl.


    

Claims (14)

 PATENT CLAIMS 1. dye based on at least one laser dye molecule, characterized in that it has at least one fluorescent dye molecule residue whose fluorescence area overlaps as far as possible with the absorption area of the laser dye molecule residue and which is linked to the laser dye molecule residue directly or via bridge members of at most 20 Å in length such that the n-electron systems of the individual laser dye or fluorescent dye molecule residues do not form a conjugation system capable of mesomerization together.  2. Dye according to claim 1, characterized by the general formula X (CRIR2) n X [(CRIR2) n Xln wherein n is 0 or an integer from 1 to the number corresponding to a chain length of 20 Å, m 0, 1, 2 or 3, X is a laser dye residue L or fluorescent dye residue F and R , and R2 independently of one another can each represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, with the proviso that one of the groups X represents a radical, all radicals F can be identical or different and the bridge members CRz R2 can also be substituted by oxygen or Sulfur atoms can be linked together.  3. Dye according to claim 1, characterized by the general formula EMI1.1  wherein X and nl have the meaning given in claim 2. point.  4. Dye according to claim 1, characterized by the general formula EMI1.2  wherein X has the meaning given in claim 2 and Z has the meaning 0 or NH 5. Dye according to claim 1, characterized by the general formula EMI1.3  wherein X has the meaning given in claim 2 and nl represents an integer from 1 to 13, preferably from 1 to 4.  6. Dye according to claim 1, characterized by the general formula EMI1.4  wherein X and nl have the meaning given in claim 5.  7. Dye according to claim 1, characterized by the general formula EMI1.5  wherein X has the meaning given in claim 2.  8. Dye according to claim 1, characterized by the general formula HCkCH2) ni X3 wherein X and nl have the meaning given in claim 5.  9. A method for producing a dye according to claim 1, characterized in that a reactive group-bearing, first laser dye or fluorescent dye with a bridging compound, the molecular length of which does not significantly exceed 20 Å and which has at least two reactive groups, at least one of which is able to covalently bond with the first dye, is reacted in equimolar amounts and the reaction product with its second reactive group is reacted with a second dye which is different from the first dye, one of the dyes being a laser dye.  10. The method according to claim 9, characterized in that an aromatic ring system under the conditions of metasubstitution with at least one fluorescent dye and a laser dye, which carry substitutable groups, is successively implemented.  11. The method according to claim 9, characterized in that a laser dye and at least one fluorescent dye are reacted with an anchor molecule.  12. A method for producing a dye according to claim 1, characterized in that a laser dye and at least one fluorescent dye are linked directly to one another, the formation of a common conjugated system being prevented by sufficiently voluminous substituents.  13. The method for producing a dye according to claim 1, characterized in that a laser dye and at least one fluorescent dye are each connected to a bifunctional bridge-forming molecule, the second reactive group of the bridge-forming molecule subsequently being linked to a common anchor molecule.  14. The method according to claim 13, characterized in that the anchor molecule consists of an aromatic hydrocarbon, a heterocycle or a high polymer.  The invention relates to new dyes and processes for their production, namely new dyes which have a significantly higher efficiency and a significantly higher service life when used in dye lasers.  Of the laser dyes usually used, only a small fraction of the white excitation light of the xenon flash lamps, which are mostly used as an excitation light source, can be used, namely predominantly that which is absorbed by the narrow, long-wave absorption band of the dye molecule. Since the half-widths of the absorption band of the customary laser dyes are typically 5000 cm -1, the emission spectrum of the xenon flash lamps from the permeability limit of the quartz glass bulb at about 200 nm (= 50,000 cm-1) to above the absorption limit of the long-wave absorbing dyes at about 1 ", lm (= 10,000 cm-1 is sufficient, i.e. it comprises 40,000 cm-1, typically only about one eighth of the available power of the exciting xenon flash lamps can be used. In fact, the fraction used is usually still much lower, since the energy emitted by the xenon flash lamps is not evenly distributed over the entire spectrum, but rather increases significantly after short wavelengths, and the more so, the shorter the rate at which the current pulse rises Flash lamp and the higher the current density in it. Since both the current rise rate and the current density are chosen to be as high as possible in the customary dye lasers for reasons well known to the person skilled in the art, usually only about a tenth of the incident light can be absorbed and converted into laser radiation. This and the losses in the conversion of electrical to optical energy in the flash lamp result in a maximum efficiency (= laser energy / electrical pulse energy) of only 1.5% for the best dye lasers in existence today. A more detailed description of these conditions can be found at F.P. Schäfer: Principles of Dye Laser Operation in: Dye Lasers, F.P. Schäfer, Ed., Springer Verlag, Berlin, Heidelberg, New York, 1973. It is therefore an object of the present invention to provide dyes and processes for their production which utilize as much of the excitation light as possible and thereby achieve a higher efficiency of the dye laser . Another goal is the creation of dyes, which make it possible not only to operate dye lasers in pulse mode with xenon flash lamps, but also using continuously burning, incoherent light sources with an essentially white spectrum, such as high-pressure xenon lamps, metal halide lamps or the sun, for example Intensity when using conventional dyes is not sufficient for the continuous operation of dye lasers.  Another object of the invention is to increase the useful life of laser dyes. It is known that all laser dyes are destroyed more or less quickly photochemically, which is essentially caused by the ultraviolet component of the excitation light. For example, the useful life of a solution of Rhodamine 6G in a dye laser from L. Ringwelski and F. P. Schäfer (F. P. Schäfer, Liquid Lasers, in Laser Handbook, F. T. Arecchi and E. O. Schulz-Du Bois, Eds., North Holland, Amsterdam, 1972, p. 404) can be increased tenfold by filtering out the ultraviolet portion of the excitation light using a 0.75 molar copper sulfate solution.  Finally, it is an object of the invention to provide new dyes for textiles, leather and the like, and pigment dyes for paints, varnishes, printing inks and the like. Ä. To create that have superior lightfastness.  Attempts have been made to make better use of the excitation light spectrally by using mixtures of the laser dye with shorter-wave absorbing, well-fluorescent dyes instead of a single laser dye, the fluorescence of the added dye being partially absorbed by the laser dye and thereby effectively increasing the excitation power in the laser dye was (GB-PS 1 255 399). However, the increases in the output powers of the dye laser given there after the addition of the fluorescent dye are not a measure of the better utilization of the excitation light, but rather a purely arbitrary, manipulable measure, as can be shown by the following consideration. In Example 3 or above. GB-PS is used in a dye laser acridine red as a laser dye with a concentration of 10-4 M and a certain laser energy is measured at a capacitor voltage of 15 kV. Rhodamine 6G is then added as the fluorescent dye until the solution is 10-4 with respect to both dyes, and an increase in the laser energy by a factor of 9.5 is measured. If one were to lower the capacitor voltage so far that one would stay just below the threshold of the laser emission with the pure acridine red solution, and then use the mixture at the same voltage, one would measure a certain output energy, now because of the additional fluorescence of the rhodamine, the increase in the excitation power of the acridine red would exceed the laser threshold, which meant an increase in the output power by the factor infinity. By adjusting the capacitor voltage between the threshold value for the laser emission and 15 kV, each factor between infinity and 9.5 can now be achieved, as can the factor below 9.5 by further increasing the capacitor voltage. A significantly better measurement number for the improvement of the efficiency is from W. Schmidt, W. Appt and N. Wittekindt, Z. Naturforsch. A27 (1972) 37. The electrical pulse energy at which a certain laser energy is achieved with the laser dye alone is measured, and the mixture is then used to determine the electrical pulse energy at which the same laser power is achieved as with the laser dye alone. The ratio of the two electrical energies is a very good measure for the improvement achieved in the utilization of the excitation light spectrum. The latter authors found loc. cit. that in their cresyl violet dye laser the excitation energy to obtain 10 kW laser power was reduced by a factor of two when an optimal amount of rhodamine 6G was added as the fluorescent dye to the solution, and that with a laser power of 25 kW this factor was 2 , 7 was.    However, the known method described above of improving the laser efficiency by mixing fluorescent and laser dyes has serious disadvantages. Thus, at the concentrations that are usually used in dye lasers excited with flash lamps, as a rule <10-4 M, the energy transfer from fluorescent dyes to the laser dye is by no means complete. A large part of the fluorescent light emitted isotropically in all directions is lost through the cuvette walls instead of being usefully reabsorbed by the laser dye molecules as long as the energy transfer is radiating. However, the energy transfer from the fluores ** WARNING ** End of CLMS field could overlap beginning of DESC **.