Photoreactions of Organic Halides, Alcohols, and Olefins with Tetrakis(pyrophosphito)diplatinate(II)

Article abstract of DOI:10.1021/j100345a043

The photoreactions of ^4- (Pt2) with organic halides (RX), alcohols (RR'CHOH), and olefins have been investigated.The second-order rate constants (k_q) for the reactions of ³A_2uPt2 (³Pt2^*) with these substrates have been determined by Stern-Volmer quenching experiments.With RX, the k_q values increase with decreasing C-X bond strength.Flash-photolysis experiments establish that the primary step of the photoreactions of Pt2 with RX is halogen atom transfer.Broad-band irradiation of RR'CHOH (λ > 300 nm) in the presence of Pt2 leads to the production of an aldehyde or ketone and molecular hydrogen.The k_q values for aliphatic and benzilyc alcohols range from 1E4 to 1E6 M^-1 s^-1, being highest with benzyl alcohol.Flash-photolysis experiments confirm that the first step in these reactions is H-atom transfer.Photoisomerization of cis- and trans-stilbenes are sensitized by Pt2.