Rhodium complexes phthalocyanines

A water-soluble hydroformylation catalyst was developed by Xi and co-workers [65]. Third generation PAMAM dendritic ligands, with hydrophilic amine or sulfonic acid end groups, were phosphonated and the rhodium complexes thus formed were found to catalyse efficiently the hydroformylation of 1-octene and styrene, under very mild conditions. Water-soluble dendritic cobalt phthalocyanines that exhibited catalytic activities and oxidised thiols in the presence of oxygen, have been synthesised by Kimura and co-workers [66]. The catalytic activity of the phthalocyanines was influenced by a egation of the catalytic sites that results fi om strong intermolecular cohesive forces. It was proposed that steric isolation, enforced by the addition of a bulky dendritic coaf around the active phthalocyanine unit, could improve the catalytic activity. Acid terminated polyamide dendrimers were coupled to a phthalocyanine core to produce the desired water-soluble cobalt phthalocyanines, which were tested subsequently for catalytic activity and stability. The results obtained showed that the aggregation of phthalocyanines was reduced the catalytic activity was improved and the stability of the catalyst was improved by addition of the dendritic substituents. 

Continuous, flash, and laser flash photolyses of phthalocyanine complexes [Rh(pc)(MeOH)X], with X = Cl, Br, or I, show that replacement of halide by methanol is a redox-induced process, via rhodium(III)-pc and rhodium(II) species/ This may be compared with copper(II) analogues, where redox-induced substitution involves copper(III)-pc complexes/ Axial ligand substitution processes must also be involved in photoinduced hydrogen abstraction from coordinated solvent in rhodium(III)-phthalocyanine complexes/ ... 

For the insertion of noble metal ions into phthalocyanine H2(Pc), the latter is favorably activated by transformation into its lithium derivative. Thus, reaction of Li2(Pc) with [Rh(COD)Cl]2 in a large excess of a donor solvent L yielded the Rh(II) complexes, Rh(Pc) L2 (L = Py, BuNH2, Bipy, Pyz) [119]. The formation of these Rh(II) species is very remarkable because Rh insertions normally yield either Rh(I) or Rh(III) derivatives. Recently, tris(ethylenediamine)-rhodium(III) iodide [Rh(en)3]I3 and phthalodinitrile have been used to prepare H [RhI2(Pc)] 2phthalodinitrile. This material was then transformed into [Rh(OH)2(Pc)] by treatment with first H2SQ4 and then KOH. Treatment of... 

Preliminary results of the reaction between vanadium(iii)-tetrasulpho-phthalocyanine complex with oxygen have been reported these data were compared with those obtained for the corresponding reaction of the hexa-aquo complex ion. The oxidation of methyl ethyl ketone by oxygen in the presence of Mn"-phenanthroline complexes has been studied Mn " complexes were detected as intermediates in the reaction and the enolic form of the ketone hydroperoxide decomposed in a free-radical mechanism. In the oxidation of 1,3,5-trimethylcyclohexane, transition-metal [Cu", Co", Ni", and Fe"] laurates act as catalysts and whereas in the absence of these complexes there is pronounced hydroperoxide formation, this falls to a low stationary concentration in the presence of these species, the assumption being made that a metal-hydroperoxide complex is the initiator in the radical reaction. In the case of nickel, the presence of such hydroperoxides is considered to stabilise the Ni"02 complex. Ruthenium(i) chloride complexes in dimethylacetamide are active hydrogenation catalysts for olefinic substrates but in the presence of oxygen, the metal ion is oxidised to ruthenium(m), the reaction proceeding stoicheiometrically. Rhodium(i) carbonyl halides have also been shown to catalyse the oxidation of carbon monoxide to carbon dioxide under acidic conditions ... 

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