Tetraphenylporphyrine

Dietel E, Hirsch A, Zhou J and Rieker A 1998 Synthesis and electrochemical investigations of molecular architectures involving Cgg and tetraphenylporphyrin as building blocks J. Chem. See., Perkin Trans. 2 1357-64... 

Bull R A and Bulkowski J E 1983 Tetraphenylporphyrin monolayers—formation at the air water interfaoe and... 

New PHB materials are composed of Zn-tetraben2oporphyrin—aromatic cyanide—poly (methyl methacrylate) (180) or of tetraphenylporphyrin derivatives dispersed in polymer matrices such as PMMA and polyethylene (181). A survey of such materials has been given (181). 

LB Films of Porphyrins and Phthalocyanines. The porphyrin is one of the most important among biomolecules. The most stable synthetic porphyrin is 5,10,15,20-tetraphenylporphyrin (TPP). Many porphyrin and phthalocyanine (PC) derivatives form good LB films. Both these molecules are important for appHcations such as hole-burning that may allow information storage using multiple frequency devices. In 1937 multilayers were built from chlorophyll (35). 

Dye-Sensitized Photoisomerization. One technological appHcation of photoisomerization is in the synthesis of vitamin A. In a mixture of vitamin A acetate (all-trans stmcture) and the 11-cis isomer (23), sensitized photoisomerization of the 11-cis to the all-trans molecule occurs using zinc tetraphenylporphyrin, chlorophyU, hematoporphyrin, rose bengal, or erythrosin as sensitizers (73). Another photoisomerization is reported to be responsible for dye laser mode-locking (74). In this example, one metastable isomer of an oxadicarbocyanine dye was formed during flashlamp excitation, and it was the isomer that exhibited mode-locking characteristics. 

Nickel 5,10,15,20-tetraphenylporphyrin [14172-92-0] M 671,4, A-n, 414(525)nm. Purified by chromatography on neutral (Grade I) alumina, followed by recrystn from CH2Cl2/MeOH [Yamashita J Phys Chem 91 3055 1987]. 

A, A, A, A -tetramethylethylenediamine trimethyl orthoformate tetrapropylammonium perruthenate tetraphenylporphyrin sulfonated triphenylphosphine triisopropylbenzensulfonyl chloride triphenylcarbenium tetrafluoroborate tetrabutylammonium triphenylmethanethiolate toluenesulfonyl... 

The metalloporphyrin-catalyzed decomposition of ethyl azidoformate in the presence of an arene has been investigated but with little success in improving the yields of the 1 //-azepines.151 The nickel and copper complexes had no effect, whereas the cobalt-tetraphenylporphyrin complex accelerated the decomposition rate of the azido ester but produced more A-arylurethane rather than 1//-azepine. 

Similar results are observed in the conjugative addition of CH-acidic methylene compounds with the metal derivatives of 2-nitro-5,10,15.20-tetraphenylporphyrin (6). The nickel porphyrin 6 (M = Ni) yields with an excess of dimethyl malonate the cyclopropane derivative 7 whereas the copper porphyrin 6 (M — Cu) forms with two equivalents of malononitrile the bisadduct 8.111... 

Cyclopropane-fused chlorins derived from tetraphenylporphyrins can be prepared by the aforementioned carbene cycloaddition route, e.g. conjugative addition of nialonate to nickel(II) nitrotetraphenylporphyrin 14 (M = Ni) yields the cyclopropane-fused chlorin 15.22... 

The diimide reduction of nietal-free 5,10,15,20-tetraphenylporphyrin (2) or 5,10,15,20-tetraphenyl-2,3-dihydroxychlorin (3) gives the bacteriochlorins 1 in good yields. 

The observation that addition of imidazoles and carboxylic acids significantly improved the epoxidation reaction resulted in the development of Mn-porphyrin complexes containing these groups covalently linked to the porphyrin platform as attached pendant arms (11) [63]. When these catalysts were employed in the epoxidation of simple olefins with hydrogen peroxide, enhanced oxidation rates were obtained in combination with perfect product selectivity (Table 6.6, Entry 3). In contrast with epoxidations catalyzed by other metals, the Mn-porphyrin system yields products with scrambled stereochemistry the epoxidation of cis-stilbene with Mn(TPP)Cl (TPP = tetraphenylporphyrin) and iodosylbenzene, for example, generated cis- and trans-stilbene oxide in a ratio of 35 65. The low stereospecificity was improved by use of heterocyclic additives such as pyridines or imidazoles. The epoxidation system, with hydrogen peroxide as terminal oxidant, was reported to be stereospecific for ris-olefins, whereas trans-olefins are poor substrates with these catalysts. 

It has square planar coordination (Pd-N 2.010-2.017 A) similar to the value of 2.009 A in the tetraphenylporphyrin analogue, prepared by a similar route. As with nickel, macrocycle complexes can be made by in situ template... 

Becker et al. (1985 a) also investigated the photolytic dediazoniation of arenediazonium salts sensitized by zinc tetraphenylporphyrin (ZnTPP). Due to the very different lifetimes of singlet and triplet ZnTPP (1.8 ns and 1.4 ms, respectively) it is possible to differentiate between singlet and triplet electron transfer reactions using different diazonium salt concentrations. 

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