DE19730469A1 - Hydrophilic porphyrin derivatives including modified polymers - Google Patents

Abstract

Metallised or unmetallised porphyrin derivatives (I) of formula: (A) with specified substituents; (in which at least one of R1-3 = (ar)alkylsulfonyl, (alk)arylsulfonyl, pyridin-N-(ar)alkyl or (alk)aryl with 1-8 carbon (C) atoms, the rest may also = hydrogen (H), (ar)alkyl or (alk)aryl; at least one of R4-8 = hydroxyl (OH) or a polymer residue derived from polyesters, poly(methyl methacrylates) (PMMA), poly(meth)acrylic acids or their esters, polymethyl-amides, polyacetals, polyimides and/or polyamides and the corresponding monomers, the rest may also = H; M = a metal cation or saturation with H atoms. Also claimed are (i) photosensitisers containing (I); and (ii) containers or articles with surface zones of polymer-bound (I) for detoxification and/or disinfection of objects, water or environments containing water.

Description

The invention relates to metallized or unmetallated porphyrin derivatives and a process for their manufacture. Furthermore, the subject of this The present invention photosensitizers comprising the porphyrinderi mentioned vate as far as the use of photosensitizers to initiate photoche mixer reactions, especially for the catalytic formation of singlet Oxygen.

The invention relates in particular to surface-loaded porphyrin derivatives, which are covalently bound to a polymeric material.

Hydrophilic polymer-bound porphyrins have advantageous properties as Photosensitizers. These advantages come in particular at a border layer polymer - water to advantage, because with these new substances too otherwise hydrophobic polymer surfaces in a sufficiently intense Can be brought into contact with an aqueous phase. So you can Initiate photochemical reactions that would otherwise not take place. For  the water-soluble polymer-bound porphyrins are potentially other Areas of application or modes of operation as for the water-insoluble hydrophilic Polymers.

Unmetallated porphyrins and also metallized porphyrins can be considered efficient Photosensitizers are used. You will be exposed to light sufficient wavelength electronically excited. In a suitable combination with Chemical reactants can either use the excited sensitizers transfer the energy or a charge to the reaction partner concerned, which reacts in subsequent reactions. As an acceptor of energy a variety of other species come into question. Can also be electronically excited porphyrins both as donors and acceptors to form Exciplexes act, which can then lead to chemical reactions (T. Mashiko, D. Dolphin, Comprehensive Coord. Chem. 2, 1987, 813-898).

Of application engineering interest z. B. sensitized photooxygenia stances, sensitized photoisomerizations, sensitized photocycloadditio and sensitized photodesulfonylations. The sensitized activation of oxygen, which is in the ground state as triplet oxygen and is sensitive can be converted into singlet oxygen is particularly important: Singlet oxygen has a different reactivity from triplet oxygen. In many practical cases, the sensitizer becomes homo in the reaction mixture gene solved. However, it is disadvantageous here that the sensitizer has been removed Reaction when working up the reaction mixture often with great effort must be separated and possibly recycled. In addition, it is often required that the Product may no longer contain any sensitizer residues. A well-known way To reduce the effort is to send the sensitizer to Ober surfaces of carrier materials either physically (by adsorption) or chemically (through covalent, coordinative or electrostatic bonding) fix. He can then z. B. easily abge by filtration can be separated and reused. Examples of ver  use of sensitizers and their heterogenization (A.M. Braun, M.-T. Maurette, E. Oliveros, Photochemical Technology, John Wiley & Sons, Chichester 1991; H. Böttcher (Ed.), Technical Applications of Photochemi stry, German publisher for raw materials industry 1991).

The adsorption of Rose Bengale on silica gel is described by S. Tamagaki et al. (J. Org. Chem. 45, 1573, 1980).

Salt formation is, inter alia, by D. Brkic et al. (J. Mol. Catal. 3, 173, 1977/78) for Rose Bengale on silica gel and by F. Le Guern et al. (Bull. Soc. Chem. Fr. 130, 753, 1993) for tin porphyrins on silica gel and zeolites wrote.

A.P. Shaap et al. (J. Am. Chem. Soc. 97, 3741, 1975) describe the implementation tongue of Merrifield resin, a cross-linked copolymer of chloromethylstyrene and divinylbenzene, with Rose Bengale. Ester groups are between the Polymer and the dye formed. The resulting photosensitive polymer is hydrophobic and poorly soluble in most organic solvents. The Increasing the hydrophilicity of this polymer group is described by A.P. Shaap et al. (J. Am. Chem. Soc. 101, 4016, 1979). The use of ethylene glycol methacrylic ester and ethyl glycol dimethyl acrylate as a second component in the Copolymerization of chloromethylstyrene provides more hydrophilic polymers.

D. Woehrle et al. (Makromol. Chem. 192, 819, 1991) report a polymer with covalently bound zinc tetraphenylporphyrin. Is used Zinc-5- (4-aminophenyl) -10,15,20-triphenylporphyrin. This is on the one hand to Polyvi tied nylchormethylstyrene and on the other hand to activated polymethacrylate as an amide. Also a copolymer of poly (N-vinyl-2-pyrrolidone) methacrylic acid was used in which the free carboxylic acid groups after the amide formation were methylated.  

Heuermann et al. (Photodynamic Therapy and Biomedical Lasers 855, 1992) report on the connection of metalated 5,10,15,20-tetrahydroxyphenyl-, Tetraaminophenyl, tetracarboxyphenylporphyrins on methoxypolyethylene.

WO 93/00815) describes the physical bonding of unmetallated porphyrins on polymers such as cellulose and their derivatives and on polyolefins and oils finish polymers described. To represent the photosensitive polymers is called an extraction process and that from the melt pulling. It will the representation of photosensitive polymers from dye monomers and described a copolymer. Unmetallated porphyrins are used det. The monomers are produced by the reaction of porphyrins, which are an alcohol own group, and obtained methacrylic acid chloride. The second monomer is Methyl methacrylate. The result is a modified polymethylmetha crylate, which has bound the dye via an ester function. Even the pure one Polymer with the dye as the alcohol component of the ester function is wrote. Protoporphyrindi is another dye-bearing monomer methyl ester used, which is copolymerized with methyl methacrylate.

H. Kamogawa et al. (J. Polymer Sci. 12, 2317, 1974) report on the Dar provision of monomers from vinyl benzyl esters with metallized and unmetallated Protoporphyrin from chloromethylstyrene and the protoporphyrin. This monomer was copolymerized with N-vinylpyrrolidone to give water-soluble polymers reach. Here is the implementation of a copolymer of chloromethylstyrene and N-Vinylpyrrolidin described with metallated and unmetallated porphyrins. As connecting group between the photosensitizer and the polymer one ester group and one Schiff base. Porphyrins with carboxylic acid groups and other aldehyde groups used.

M. Kamachi et al. (Macromolecules 20, 2665, 1987) describe two in one The copolymerization of unmetallated 5- (4-acryloyloxyphe  nyl) -10,15,20-triphenylporphyrin and 5- (4-methyacryloyloxyphenyl) -10,15,20-triphenyl porphyrin with methyl methacrylate. That with iron, vanadium or cobalt metallized polymer was by subsequent metallization or by the Use of metallized monomers obtained (Chem. Letters 2331, 1987).

M. Kamachi et al. (J. Polymer Sci. 21, 693, 1983) describes the polymerization of 5- (4-acryloyloxyphenyl) -10,15,20-triphenylporphyrin. The use of the metalated monomer has been described. The polymer obtained is insoluble in ethanol, acetone, water and hexane. The unmetallated polymer could be subsequently metalized with copper.

H. Eichhorn et al. (Macromol. Chem. Phys. 196, 115, 1995) describe the Representation of monomers based on unmetallated 5,10,15,20-tetraphe nylprophyrin. Double bond-containing groups were in the four para positions of the phenyl rings inserted. So was about the phenol group methacryloyl tied up. The copolymerization with styrene gave polymers which contain the porphyrin as a node.

D.H. Grayson et al. (Sol. Chem. R & D Eur. Community, Ser. D., 2, 51, 1983) describe a polymer made from polyvinylpyridine-bonded zinc tetraphenylporp hyrin.

W. Wolters describes the use in DE 38 36 759 A1 and DE 39 24 815 A1 of phthalocyanines and diazotized β-naphthol, physically bound, the is fixed with a binder as a catalyst for activating oxygen. As Binders are on the one hand acrylic acid esters and / or methacrylic acid esters and on the other hand, polyurethanes are used.

The well-known photosensitive polymers based on polymethyl methacrylate are either water-soluble or insoluble. A polymer with hydrophilic However, character that is insoluble in water is not known. The one based  of metallized and unmetallated tetraphenylporphyrin bound porphyri ne in the known polymers have no groups in the para position of the Phenyl groups that carry a positive or negative charge. Access to Polymers based on polymethyl methacrylate and tetraphenyl porphyrins have only been described via the monomers.

The aforementioned object of the present invention is achieved in a first embodiment by metalized or unmetallated porphyrin derivatives of the general formula I.

in which
R ₁ , R ₂ and R ₃ each represent hydrogen, alkyl, aryl, aralkyl or alkaryl, alkyl, aryl, aralkyl or alkaryl sulfonate, and also pyridine-N-alkyl, aryl, alkaryl or aralkyl, each with 1 to 8 carbon atoms with the proviso that at least one of the radicals R ₁ , R ₂ or R ₃ ≠ is hydrogen, alkyl, aryl, aralkyl or alkaryl, R ₄ , R ₅ , R ₆ , R ₇ and R ₈ each for hydrogen, a hydroxyl group or a polymer radical which is derived from polyesters, polymethyl methacrylates, poly methacrylic acid, polyacrylic acid and their esters, polymethacrylamides, polyacetals, polyimides and / or polyamides and their respective monomer units with the proviso that at least one of the radicals R ₄ , R ₅ , R ₆ , R ₇ or R ₈ ≠ is hydrogen and
Me stands for a metal cation or saturation with hydrogen atoms. Me stands in particular for a metal cation with a semi-occupied or fully occupied d-electron shell and aluminum.

Surprisingly, it was found that the optionally hydrophilic porphyrin derivatives of general formula I made available for the first time are efficient sensitizers which can also be easily covalently bound or bound to polymers. By modifying the substituents R ₁ , R ₂ and R ₃ with polar groups, the hydrophilicity of these polymers can be controlled in a wide range, so that on the one hand hydrophobic polymers (ie no polar groups) and on the other hand even water-soluble polymers (high proportion of polar groups) can be produced. Between these two extremes are hydrophilic but water-insoluble polymers. In addition, water solubility can be controlled by the degree of polymerization of the base polymer.

In a particularly preferred embodiment of the present invention, the metallated or unmetallated porphyrin derivatives of the general formula I are characterized in that R ₄ , R ₅ , R ₇ and R _{8 are} hydrogen and R _{6 is} a hydroxyl group. These compounds preferably serve as the starting material for the reaction with monomer units or polymer units for the covalent fixation of the porphyrin derivatives, in particular by transesterification of existing ester groups.

Another aspect of the invention is the introduction of sulfonic acid groups in the alkyl, aryl, alaryl or aralkyl groups of the porphyrin derivative. It can the degree of sulfonation is specifically controlled by adding the sulfonating agent which can change the hydrophilic nature of the polymer. The sulfonation can be carried out before the monomers are prepared or after the representation of the polymers.  

Another aspect of the invention is the alkylation of the pyridine groups Porphyrin derivatives. The degree of alkylation can be determined by adding the alkyl be controlled in a targeted manner. The alkylation can be done before manufacturing of the monomers or after the preparation of the polymers. For the Alkylation, alkyl derivatives with 1 to 8 carbon atoms are particularly suitable.

Another aspect of the invention is the introduction of metals in particular with half-filled d-electron shell after the unmetallated photosensitive Polymer is present. The porphyrin derivatives particularly preferably contain zinc as central cation.

A special aspect of the invention is the representation of porphyrin-containing Polymethyl methacrylates via the transesterification of the ester groups present 5- (4-hydroxyphenyl) -10,15,20-triarylporphyrin derivatives. The Porphyrins can be metallized or unmetallated.

Another preferred embodiment of the present invention consists in a process for the preparation of porphyrin derivatives of the general formula I by reaction of porphyrin derivatives of the general formula II

in which
R _{1 '} , R _2' and R _{3 '} each represent hydrogen, alkyl, aryl, alkaryl or aralkyl each having 1 to 8 carbon atoms and the proviso that at least one of the radicals R _1' , R _{2 '} or R _{3 '} ≠ is and
Me, R ₄ , R ₅ , R ₆ , R ₇ and R _{8 have} the meaning given above with a sulfonating agent, optionally followed by subsequent metalation.

For the purposes of the present invention, sulfony is particularly preferred Chlorosulfonic acid or concentrated sulfuric acid per se known methods used.

Another process for the production of porphyrin derivatives of the general Formula I is that about four parts of pyrrole, about one to three pyridine carboxyaldehyde and about a part of benzaldehyde with subsequent N-alkylly tion and possibly metalation.

A further preferred embodiment of the process according to the invention for the production of porphyrin derivatives consists in that porphyrins of the general formula I, where R ₁ , R ₂ , R ₃ and Me have the abovementioned meaning, R ₄ , R ₅ , R ₆ , R ₇ and / or R _{8 represents} hydrogen or a hydroxyl group with the proviso that at least one of the radicals R ₄ , R ₅ , R ₆ or R _{7 represents} a hydroxyl group
with polyesters, polymethyl methacrylates, polymethacrylic acid, polyacrylic acid and their esters, polymethacrylamides, polyacetals, polyimides and / or polyamides and their respective monomer units.

For the purposes of the present invention, the above are particularly preferred Porphyrin derivatives mentioned with polymethyl methacrylate and / or polycarbona implemented.  

Another aspect of the invention is the representation of porphyrin derivatives the copolymerization of methacrylate with metallized and unmetallated mono mer of the esters from methacrylic acid or acrylic acid and 5- (4-hydroxyphe nyl) -10,15,20-arylporphyrin derivatives. The latter monomers Contain sulfonic acid groups or pyridinium salts. The photos obtained in this way Sibilizers are attached to the polymer structure via a covalent bond and stick out of the polymer. They are not inside the polymer embedded nodes.

Another embodiment of the present invention relates to photosensitivity catalysts containing at least one porphyrin derivative of the general formula I in one Contain amount from 0.1 to 10 wt .-%. Here is the porphyrin derivative general formula I covalently or in non-covalently bound form in one Polymer matrix before. Is particularly preferred in the sense of the present invention the covalent fixation of the porphyrins in the carrier material.

The main polymeric materials used are PMMA and polycarbonates technical applications interesting because they have beneficial properties show: inexpensive, mechanically stable, weatherproof, lightfast, trans parent in the area of light required to excite the sensitizers.

According to the invention, the polymer matrix can preferably consist of fibers, granules, Nonwovens, woven fabrics, knitted fabrics, knitted fabrics or any shaped bodies, for example membranes exist.

Another aspect of the invention is the use of photosensitive mono mers and polymers as sensitizers for photochemical reactions. The Monomers and polymers shown are suitable for the transfer of Light absorbed energy on chemical substances.

In the prior art (WO 93/00815) attempts have been made to porphyri  ne to fix to polymers. The procedure here was that regenerated cellulose was stained with TRPyP and cytotoxicity was observed.

For applications in which, however, long-term stability of the polymer-fixed If sensitizers are required in an aqueous environment, it is a disadvantage that Bind porphyrin derivatives to cellulose because cellulose slowly hydrolyzes. This disadvantage does not exist in the case of covalent binding to PMMA. Though it has been found in the prior art that cell growth in a direct Contact with bacterial cultures is inhibited. The porphyrins used but are characterized by the fact that they are substituted four times symmetrically, none Include central atom and possess positively charged 4-alkylpyridines.

In our own experiments within the scope of the present invention, surprisingly, however, that when irradiating PMMA 5- (4-Hydroxyphenyl) -10,15,20-triphenylporphyrin, which is in direct contact with a air-saturated aqueous phase no formation of singlet oxygen observed could be tested. The difference to the prior art, in which this too Dye used can possibly be explained by the fact that a direct Contact with the bacterial culture in question was ensured while at According to the invention, try a diffusion barrier at the boundary layer Polymer water had to be overcome.

An important difference of the present invention to TRPyP derivatives of State of the art is that they are built symmetrically and have no function nelle group for covalent bonding. According to the invention Symmetrical porphyrins synthesized, in particular via an ester function are fixed to a carrier material.

The use of the known tetra-acrylated tetra-5,10,15,20- (4-hydroxy phenyl) prophyrin as a comonomer in the preparation of photosensitive PMMA includes the dye as a crosslinking point in the polymer structure.  

As a result, only small amounts of dye on the surface of the polymer reach and thus be photosensitive. The yield of singlet oxygen is based on the number of dyes significantly reduced. In the invention Porphyrin derivatives, the dye units are freely accessible as they are only available via a functional group are bound to the support material.

The use of the known 5- (4-hydroxyphe nyl) -10,15,20-triphenylporphyrin in aqueous systems calls for experiments present singlet oxygen formation. The fiction however, dyes produced according to have a higher hydrophilicity and are thus able, among other things, to achieve good singlet oxygen formation rates produce. The known method for producing the polymer via the radical polymerization takes 5 to 6 days or with the copolymer tion with styrene 2 days. The preferred method according to the invention via the Esterification delivers a product within a few hours.

By modifying the bound porphyrins, the activation of oxygen was nevertheless possible according to the invention. The modification consists in attaching negatively or positively charged groups to the porphyry skeleton. This strategy was the first to produce porphyrin derivatives of the general formula I which contain the following common features:

• - cargo
• - Shortcut.

Another embodiment of the invention therefore includes the use of Photosensitizers according to the present invention for the formation of Singlet oxygen from triplet oxygen by exposure to visible Light, especially for cleaning contaminated liquids, for example wise water.

A special embodiment of the invention consists in that metallization,  Sulfonation, alkylation can only take place on the finished modified polymer. This results in particular in the possibility of more targeted control of the respective grades.

Embodiments example 1 5- (4-Hydroxyphenyl) -10,15,20-tris (4-sulfonatophenyl) porphyrin

In 10 ml of concentrated sulfuric acid, 500 mg of 5- (4-hydroxyphe nyl) -10,15,20-triphenylporpyhrin dissolved. The solution was at temperature for 10 h stirred at 110 ° C. After cooling and neutralization, that was fancy product separated. Purification was carried out using column chromatography on silica gel with acetone / petroleum ether as eluent.

Example 2 Zinc (II) -5- (4-hydroxyphenyl) -10,15,20-tris (4-sulfonatophenyl) porphyrin

A mixture of 1 g of 5- (4-hydroxyphenyl) -10,15,20-tris (4-sulfonatophe nyl) porphyrin and 54.5 mg zinc acetate was in 250 ml acetic acid and 50 ml Chloroform dissolved and heated to reflux. That failed after cooling The product was analyzed by column chromatography on silica gel with Ace Ton / petroleum ether cleaned as eluent.

A mixture of 1 g zinc (II) -5- (4-hydroxyphenyl) -10,15,20-triphenylporphyrin and chloroform were dissolved at 0 ° C with 60 ul chlorosulfonic acid in 10 ml Chloroform added. After 12 h the solution was poured onto ice and the separated organic phase. After removing the solvent, was obtained the product.  

Example 3 5- (4-Hydroxyphenyl) -10,15,20-tris (N-methyl-4-pyridinium) porphyrin

A mixture of four parts of pyrrole, three parts of pyridine-4-carboxyaldehyde and a portion of benzaldehyde in propionic acid was heated for 1 hour. The solution medium was drawn off and the resulting residue with DMF and ether washed. For further cleaning, the resulting product was cleaned using the Column chromatography on silica gel with acetone / petroleum ether as the eluent processed. The methylation was carried out with methyl p-toluenesulfonate.

Example 4 Zinc (II) -5- (4-hydroxyphenyl) -10,15,20-tris (N-methyl-4-pyridinium) porphyrin

A mixture of 1 g of 5- (4-hydroxyphenyl) -10,15,20-tris (N-methyl-4-pyridini um) porphyrin and 54.5 mg zinc acetate were dissolved in 250 ml acetic acid and 50 ml Chloroform dissolved and heated to reflux. That failed after cooling The product was analyzed by column chromatography on silica gel with Ace Ton / petroleum ether cleaned as eluent.

A mixture of 1 g of zinc (II) -5- (4-hydroxyphenyl) -10,15,20-tris (py ridinium) porphyrin was treated with 10 g of methyl p-toluenesulfonate in DMF Warming implemented. After removing the solvent, the result could Rende product be recrystallized from acetone.

Example 5 5- (4-methacryloyloxyphenyl) -10,15,20-tripyridinium porphyrin

1 g of 5- (4-hydroxyphenyl) -10,15,20-tris (pyridinium) porphyrin was added to 20 ml of DMF dissolved and with 128 ul methacrylic acid in the presence of 200 ul triethylamine transferred. After the reaction, the solvent was removed, the photo sensitive monomer taken up with ether and filtered. After removing the  The pure monomer was obtained from Ethers.

Example 6 Zinc (II) -5- (4-hydroxyphenyl) -10,15,20-tris (4-sulfonatophenyl) porphyrin (fixed)

• a) A mixture of 200 mg polymethyl methacrylate (PMMA) and 280 mg Zinc (II) -5- (4-hydroxyphenyl) -10,15,20-tris (4-sulfonatophenyl) porphyrin in Toluene was heated in the presence of p-toluenesulfonic acid. It was transesterified the polymer. By repeatedly distilling off the toluene the dye was completely fixed.
• b) 74 mg zinc (II) -5- (4-methacryloyloxyphenyl) -10,15,20-tris (4-sulfonatophe nyl) porphyrin were dissolved in DMF with 10 ml of methyl methacrylate. The polymerization was started with azo-bis-isobutyronitrile (AIBN). The Removal of the solvent gave the desired polymer as a red one Powder.
• c) 10 g of zinc (II) -5- (4-hydroxyphenyl) -10,15,20-triphenyl fixed to PMMA porphyrins was dissolved in chloroform and mixed with 6 ml of chlorosulfonic acid puts. After neutralizing and stripping the solvent won the desired polymer.
• d) 10 g of 5- (4-hydroxyphenyl) -10,15,20-tris (4-sulfonato) fixed to PMMA phenyl) porphyrins were dissolved in 200 ml of chloroform and with zinc acetate transferred. After heating and stripping the solvent, the sought polymer isolated.

Example 7 Singlet oxygen production of the dyes (porphyrin derivatives)

The ability of the dyes to produce singlet oxygen was tested using a simple test. An aqueous solution containing an excess of imidazole (0.01 mol / l) and a concentration of 3 × 10⁻ ⁵ mol / l p-Nitrosodi methylaniline (RNO) was saturated with constant stirring during the measurement with air or oxygen. Imidazole acted as an acceptor for singlet oxygen, and the intermediate endoperoxide induced bleaching of the RNO, which was monitored spectrophotometrically at a wavelength of 440 nm.

10 ml of this RNO solution were mixed with zinc (II) -5- (4-hydroxyphenyl) -10,15,20-tris (4-sulphonatophenyl) porphyrin (2 ppm) and irradiated. The singlet oxygen formation rate was determined to be 8.8 × 10⁻ ⁸ mol / l / s. For comparison, Rose Bengal had a value of 2.6 × 10⁻ ⁸ mol / l / s.

The polymer of Example 6c) was subjected to the test mentioned in suspension and irradiated. After normalization, a value of 3.0 × 10⁻ ⁸ mol / l / s was determined.

Claims (15)

1. Metallized or unmetallated porphyrin derivatives of the general formula I
in which
R ₁ , R ₂ and R ₃ each represent hydrogen, alkyl, aryl, aralkyl or alkaryl, alkyl, aryl, aralkyl or alkaryl sulfonate, and also pyridine-N-alkyl, aryl, alkaryl or aralkyl, each with 1 is up to 8 carbon atoms with the proviso that at least one of the radicals R ₁ , R ₂ or R ₃ ≠ is hydrogen, alkyl, aryl, aralkyl or alkaryl,
R ₄ , R ₅ , R ₆ , R ₇ and R ₈ each represent hydrogen, a hydroxyl group or a polymer residue which is derived from polyesters, polymethyl methacrylates, polymethacrylic acids, polyacrylic acids and their esters, polymethacrylamides, polyacetals, polyimides and / or polyamides and their respective monomer building blocks and
Me stands for a metal cation or saturation with hydrogen atoms. 2. Metallated or unmetallated porphyrin derivatives of the general formula I, wherein
R ₄ , R ₅ , R ₇ , and R _{8 is} hydrogen and R _{6 is} a hydroxy group. 3. Metallated or unmetallated porphyrin derivatives of the general formula I, where pyridine-N-alkyl stands for pyridine-N-methyl. 4. Metallized porphyrins of the general formula I, where Me stands for Zn. 5. A process for the preparation of porphyrin derivatives of the general formula I according to claim 1 by reacting porphyrin of the general formula II
in which
R _{1 '} , R _2' and R _{3 '} each represent hydrogen, alkyl, aryl, alkaryl or aralkyl each having 1 to 8 carbon atoms and the proviso that at least one of the radicals R _1' , R _{2 '} or R _{3 '} ≠ is and
Me, R ₄ , R ₅ , R ₆ , R ₇ and R _{8 have} the meaning given above with a sulfonating agent, optionally followed by subsequent metalation. 6. The method according to claim 5, characterized in that one as sulfo  Nating agent uses chlorosulfonic acid or concentrated sulfuric acid. 7. Process for the preparation of porphyrin derivatives of the general formula I according to claim 1 by reacting four parts of pyrrole, one to three parts Pyridinecarboxyaldehyde and a part of benzaldehyde with subsequent N-alkylly metalation. 8. The method according to claim 5 or 7, characterized in that porphyrin derivatives of the general formula I, wherein R ₁ , R ₂ , R ₃ and Me have the meaning given above, where at least one of the radicals R ₄ , R ₅ , R ₆ , R ₇ and / or R _{8 represents} hydrogen or a hydroxyl group with the proviso that at least one of the radicals R ₄ , R ₅ , R ₆ , R ₇ or R _{8 represents} a hydroxyl group with polyesters, polymethyl methacrylates, polymethacrylic acid, polyacrylic acid and their esters, polymethacrylamides, polyacetals, polyimides and / or polyamides and their respective monomer units. 9. The method according to claim 8, characterized in that porphyrin derivatives reacted with polymethyl methacrylate or polycarbonate. 10. Photosensitizer comprising at least one porphyrin derivative of all general formula I according to claim 1 in an amount of 0.1 to 10 wt .-%. 11. Photosensitizer according to claim 10, characterized in that the Porphyrin of general formula I covalently bound with a polymer matrix is present. 12. Photosensitizer according to claim 11, characterized in that the Polymer matrix fibers, granules, powders, nonwovens, fabrics, knitted fabrics, knitted fabrics or molded articles, in particular membranes.   13. Use of photosensitizers according to one or more of the Claims 10 to 12 for triggering photochemical reactions by Ein effect of visible light. 14. Use of photosensitizers according to claim 13 for catalytic formation of singlet oxygen from triplet oxygen by action of visible light. 15. Use according to claim 14 for cleaning contaminated liquid properties, especially water.