Platinum complexes peroxo

The complexes can be obtained from the reaction of a Rh1 complex with 02 (equation 5),37 from the reaction of a Com-superoxo complex with a reduced metal (equation 6),38 from the acid hydrolysis of a platinum-peroxo complex3 (equation 7) or from the reaction of potassium superoxide with rhodium (equation 8)40 or palladium complexes.41... 

These complexes can exist in a triangular peroxo form (7a) for early d° transition metals, or in a bridged (7b) or linear (7c) form for Group VIII metals. They can be obtained from the reaction of alkyl hydroperoxides with transition metal complexes (equations 9 and 10),42-46 from the insertion of 02 into a cobalt-carbon bond (equation ll),43 from the alkylation of a platinum-peroxo complex (equation 12),44 or from the reaction of a cobalt-superoxo complex with a substituted phenol (equation 13).45 Some well-characterized alkylperoxo complexes are shown (22-24). 

The other main group elements which form peroxo complexes are d6 and d8 systems in group VIII including iridium, palladium and platinum. The ji-peroxo complexes do not generally catalyse the epoxidation of olefins with hydrogen peroxide,95,96 but it has been found that trifluoromethyl-substituted Pd(II) and Pt(II) hydroperoxides will perform such a transformation.97... 

Stable five-membered dioxametallacyclic adducts are obtained from the reaction of Group VIII metal-peroxo complexes (Rh, Ir, Pd, R) with nucleophilic ketones and electrophilic alkenes or ketones. The adducts of R02(PPh3)2 with acetone and l,l-dicyano-2-methylpropene have been characterized by X-ray crystallography. The reaction of (Ph3P)2R02 with nucleophilic ketones involves, as the major pathway, the precoordination of the carbonyl compound to the vacant axial site of platinum prior to intramolecular 1,3-dipolar cycloaddition (equation 42). ... 

Miscellaneous.— The reaction between dioxygen platinum(ii) complexes and substituted acetylenes takes place via two discernible steps, according to reaction (9), where R = COaMe and R = cyclohexyl. There is a direct attack by the acetylene on the dioxygen ligand. Formation of u-peroxo- -hydroxo-complexes... 

The reaction of molecular oxygen complexes of iridium or platinum with sulphur dioxide to produce sulphato-complexes involves both insertion into a metal-oxygen bond and bond formation between the sulphur and the leaving oxygen, with subsequent rearrangement of the peroxo-sulphite intermediate thus generated ... 

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