Meso-tetrakis porphyrin

Decomposition of diazo compounds by iron porphyrins is a convenient method for the synthesis of non-heteroatom carbene-iron porphyrins [22]. Reaction of [Fe(F2o-TPP)] [F20-TPP = meso-tetrakis(pentafluorophenyl)porphyrinato dianion] with diazo compounds N2C(Ph)R (R = Ph, C02Et, C02CH2CH=CH2) under an inert atmosphere afforded complexes [Fe(F2o-TPP)C(Ph)R] in 65-70% yields (Scheme 2). Like the halocarbene complex [Fe(TPP)(CCl2)], [Fe(F2o-TPP)CPh2] reacted with Melm to afford six-coordinate species [(MeIm)Fe(F2o-TPP)CPh2] in 65% isolated yield. 

Fig. 3. Haptens and multivalent antigens prepared in this syudy. The viologen derivative, 4,4 -bipyridinium, l-(carboxypentyl)-l -methyl-dichloride (1), divalent antigen 2, and trivalent antigen 3. Anti-porphyrin antibodies were elicited for [5-(4-carboxyphenyl)-10,15,20-tris-(4-methylpyridyl)]porphine (3MPylC) or meso-tetrakis(4-carboxyphenyl)porphine (TCPP). meso-Tetrakis(4-methylpyridyl)porphine (TMPyP) was used to investigate the specificity of the antibody dendrimer for porphyrins...

Lebold TP, YeowEK, Steer RP (2004) Fluorescence quenching of the SI andS2 states of zinc meso-tetrakis(4-sulfonatophenyl)porphyrin by halide ions. Photochem Photobiol Sci 3 ... 

A number of metal porphyrins have been examined as electrocatalysts for H20 reduction to H2. Cobalt complexes of water soluble masri-tetrakis(7V-methylpyridinium-4-yl)porphyrin chloride, meso-tetrakis(4-pyridyl)porphyrin, and mam-tetrakis(A,A,A-trimethylamlinium-4-yl)porphyrin chloride have been shown to catalyze H2 production via controlled potential electrolysis at relatively low overpotential (—0.95 V vs. SCE at Hg pool in 0.1 M in fluoroacetic acid), with nearly 100% current efficiency.12 Since the electrode kinetics appeared to be dominated by porphyrin adsorption at the electrode surface, H2-evolution catalysts have been examined at Co-porphyrin films on electrode surfaces.13,14 These catalytic systems appeared to be limited by slow electron transfer or poor stability.13 However, CoTPP incorporated into a Nafion membrane coated on a Pt electrode shows high activity for H2 production, and the catalysis takes place at the theoretical potential of H+/H2.14... 

Subsequently, other publications have appeared involving the DA reactions of porphyrins with other dienes. For instance, the reaction of meso-tetrakis(pentafluorophenyl)porphyrin Id with the diene generated from pyrrole-fused 3-sulfolene gave rise to the isoindole-fused chlorin derivative 8 accompanied by a mixture of stereoisomeric bacteriochlorins 9 (Scheme 2) <98CC2355>. 

The water-soluble Fe porphyrin, 3Na+ [Fe(III)(TPPS)] -12H20 [H2TPPS4- = tetra-anionic form of meso-tetrakis(7r-sulfonatophenyl)porphine], has recently been shown to be an effective catalyst for the electroreduction of nitrite to ammonia [419]. The Fe meso-tetrakis(A -methyl-4-pyridyl) porphyrin and/or the Fe meso-tetrakis (jr -sulfophenyl) porphyrin complex shows a catalytic activity for the reduction of dioxygen in aqueous solutions, leading to hydrogen peroxide [420]. 

Fe model 1 (deoxy form) Fe(Tpiv)PP-(2-MeIm). The porphyrin ligand, Fe(Tpiv)PP, is the picket fence porphyrin, meso-tetrakis(a, a, a, a-o-pivalamidephenyl)porphyrin (Figure 16 of reference 9). In this chapter see Figure 7.9B. 

Figure 7.9 (A) Prevention of a-oxo dimer formation by distal-side porphyrin modifications. (Adapted with permission from the reference 19. Copyright 1985, Division of Chemical Edncation, Inc.) (B) Picket-fence porphyrin Fe(Tpjv)PP, meso-tetrakis(a, a, a, a-c>-pivalamidephenyl)porphyrin described in references 6,17,18, and 21.

The oldest methods for synthesis involve the condensation-cyclization of trifluor-omethyl or fluoroalkyl pyrroles in the presence of a metal salt. These reactions afford tetrakis(fluoroalkyl) porphyrins. The electrophilic trifluoromethylation of porphyrins is selective and leads to /I-CF3 and meso-CVT, porphyrins. While condensation of meio-trifluoromethyl-dipyrromethane with an aldehyde in acidic medium is rather difficult, it proceeds with better yields and permits a selective introduction of trifluoromethyl groups in meso The Ruppert reagent (CF3TMS) has been used to... 

P. Maillard, C. Huel, and M. Momenteau, Synthesis of new meso-tetrakis (glycosylated) porphyrins, Tetrahedron Lett. 33 8081 (1992). 

Iron(II) meso-tetrakis(2,4,6-trimethoxyphenyl)porphyrin and the triethoxy analogue have been synthesized by Vaska. These are different to the capped and picket fence porphyrins in that both sides of the porphyrin are sterically hindered. Dioxygen uptake by these iron(II) porphyrins at 25 °C in solution was found to be partially reversible. La Mar and co-workers166 have shown that the porphyrins Fe[T(2,4,6-OMe)3PP], Fe[T(2,4,6-OEt)3PP] and Fe[TpivPP] take up oxygen at low temperatures, in the absence of a base such as Melm or pyridine, to give dioxygen adducts of the... 

The eclipsed tetra-BINAP porphyrin 171 was conveniently synthesized by condensation of the meso-tetrakis(2,6-dihydroxyphenyl)porphyrin 173 with the (S)-BINAP derivative 174 in the presence of K2C03. After removal of the staggered isomer iron was inserted by addition of Fe(CO)5/I2, and the resulting Fe(III)-complex 171 was used as a catalyst (0.2%) to epoxidize a series of six styrene derivatives in the presence of an excess of PhIO. In every case the corresponding (R)-epoxides were preferentially formed in yields up to 72%. The best ee-values were obtained for the electron deficient substrates 2-nitrostyrene (80% ee) and pentafluorostyrene (74% ee), [114],... 

For the synthesis of the porphyrin the formate ester of 3j3-hydroxy-5-cholenic acid 179 was coupled via amide bonds to the a,/ ,a,j -atropisomer of meso-tetrakis(o-aminophenyl)-porphyrin 170, using the mixed anhydride... 

TMPyP meso-tetrakis(4-N-methyl-pyridiniumyl)porphyrin... 

Figure 2. C.-P.-K. model of energy minimized (MM-2, chem 3D) meso-tetrakis (p-methyl) phenyl porphyrin.

DiMagno, S.G., Williams, R.A. and Therien, M.J. (1994) Facile synthesis of meso-tetrakis(perfluoroalkyl) porphyrins spectroscopic properties and X-ray crystal structure of highly electron-deficient 5,10,15,20-tetrakis (heptafluoropropyl) porphyrin. J. Org. Chem., 59, 6943. 

Ng et al. first reported the axial ligation of zinc(II) l,8,15,22-tetrakis(3-pentyloxy) phthalocyanine (1) with meso-pyridyl porphyrins 2 and 3 in chloroform, which form the corresponding edge-to-face dyad and pentad, respectively [25], As shown by UV-Vis spectroscopy, the ground-state tt-tt interactions between the perpendicularly disposed macrocycles in these arrays are insignificant. Upon mixing of phthalocyanine 1, zinc(II) meso-tetra(/Molyl)porphyrin, and 4,4/-bipyridine in chloroform, the formation of a face-to-face hetero-dyad was also inferred by fluorescence quenching experiments. 

Ion-association adsorption of water-soluble porphyrin was studied using time-resolved TIR fluorometry. Interfacial adsorption of anionic or cationic surfactants succeeded in attracting the oppositely charged porphyrin from the mixture of cationic and anionic porphyrins in the aqueous phase, tetrakis(sulphonatophenyl)porphyiin (TPPS) adsorbed with the hexadecyltrimethylammonium ion and tetrakis(iV-methylpyridyl)porphyrin (TMPyP) with the hexadecanesulfonate [44], In addition, it was found that the application of an external electric field across the interface enabled to control the interfacial ion-association adsorption of ionic porphyrin [45]. Furthermore, TIR Raman microspectroscopy revealed the interfacial concentration of meso-tetrakis(A -methylpyridyl) porphyrinato-manganese(III) (Mn(tmpyp) +) adsorbed with dihexadecyl hydrogenphosphate (DHP) at the toluene/water interface and also revealed that the orientation of the tilt angle was 65° from the interface normal [46]. 

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