Porphyrin indium complexes

Porphyrin, tetrahydro-metal complexes geochemistry. 6, 862 Porphyrin, tetraphenyl-indium complexes radiopharmacology, 6, 971 iron complexes, 4, 260,1266 zinc complexes spectra, 6, 617... 

Ge(TPP)R2, Ge(TPP)(Fc)Ph, and Ge(TPP)Fc2) the spectrum after 2 /us was consistent with a triplet excited state, although this decayed much faster for the fer-rocenyl complexes. Addition of ferrocene to Ge(TPP)R2 also quenches triplet lifetimes. A similar situation was observed for the indium complexes In(Por)R, and the triplet-state quenching was attributed to an energy transfer process from the excited-state triplet to ferrocene. In the case of the germanium porphyrins, the longer-lived triplet state in Ge(TPP)R2 is responsible for the Ge—C bond homolysis, and both inter- and intramolecular quenching by ferrocene is observed. 

A series of indium(III) porphyrin complexes (porphyrin = TPP, OEP, Tp-CFsPP) containing axial tetrazolato and triazolato ligands have been prepared by the cycloaddition reactions of... 

Reduction of the gallium and indium complexes involves the porphyrin ir ring system . The site of electron transfer in Tl(Por)(R) is not clear. A reduction of Tl to Tl is possible in Tl(Por)(R) but the similarity in potentials between Ga(Por)(R) and In(Por)(R) suggests that reduction of this complex occurs at the porphyrin n ring system . 

Both irradiation by visible light and pyridine are required for the above insertion. The same carboxylate complexes can be prepared by reaction of acetic acid with either the alkyl(aryl)indium(III) porphyrins or the aquohydroxoindium(III) porphyrins. 

Various metal-metal single o-bonded complexes have been obtained by the reaction of metal carbonyls with metal-carbon o-bonded porphyrins or by the reaction of metal carbonyl anions and chlorometalloporphyrins (Scheme 14). For example, the reaction of dimanganese carbonyl and methyl indium(III) porphyrin gives manganese pen-tacarbonyl indium porphyrin In(Por)Mn(CO)5. The same compound is isolated when chloroindium porphyrin is allowed to react with the manganese pentacarbonyl monoanion. Various iron, cobalt, tungsten, and molybdenum complexes have been prepared by these two methods. 

Porphyrin, octaethyl-, indium hydroxide complex cyclic voltammetry, 4, 399 <73JA5140)... 

Tetraphenylporphyrin indium hydride (TPP)InH reacts with H2Os3(CO)10(NC5H5) in hot toluene to afford the cluster-bound indium-porphyrin complex H2Os3(CO)9(NC5H4)In(TPP), 56.86... 

Aluminum, Gallium, Indium, and Thallium Porphyrin Complexes, M(Por)R... 

The thallium complexes show somewhat different electrochemical behavior, and reversible oxidations are observed for both n-alkyl and n-aryl thallium porphyrins, indicating that the oxidized complexes have a more stable metal—carbon bond than the gallium or indium analogs. Spectroelectrochemistry revealed that the first oxidation is porphyrin ring-centered. The first reduction is reversible and ring... 

Overall, the UV-visible, NMR, and electrochemical data for the range of O -bonded complexes of gallium, indium, and thallium porphyrins show that there is a trend from pure a -bonded character of the M—C bond in the alkyl complexes to the much more ionic character observed for the fluorophenyl and acetylide complexes. These more ionic complexes show NMR and UV-visible characteristics more like those of the ionic M(Por)Cl or M(Por)C104 complexes. ... 

Most of the studies on organo-gallium, indium, and thallium porphyrin complexes have focused on synthesis and properties of the complexes, and rather little attention has been devoted to reaction chemistry. Two areas which have received some attention are the insertion of small molecules (SO2 or CO2) into the metal—carbon bonds and photochemical metal—carbon bond cleavage. The... 

The CO2 activation reactions seen for aluminum porphyrins are also observed for In(Por)Me (Por = OEP, TPP), which will insert CO2 in the presence of pyridine and under irradiation by visible light to give the acetato complex In(Por)OC(0)Me. The indium acetato product has been characterized by X-ray crystallography, whereas in the aluminum complex it was observed only by spectroscopy. An alternative synthesis of the acetato complex is by treatment of ln(Por)Cl by alumina and water, followed by acetic acid. For the indium and... 

Although photochemically induced cleavage of Al—C bonds in the aluminum porphyrin complexes has been exploited in several applications, relatively little is known about the intimate mechanism of this process. Similar reactivity is observed for the organo-gallium and indium porphyrins, and for these elements... 

A series of earlier papers on complexes of indium(III) with porphyrins,265 and phthalocyanines266-268 has been summarized earlier.7 The structures InLX (L = substituted porphyrin X = Cl, OAc, OPh) imply a square pyramidal stereochemistry with the indium atom situated above the ligand N4 system, and this has been confirmed by X-ray crystallography for X = C1269 and X = Me,270 but for X = MeOS02, the indium atom is in the plane of the four nitrogen atoms.271 A number of Schiff base derivatives have recently been described.272... 

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