Photoinduced reductive elimination of cyanoalkanes from hydridocyanoalkyl complexes of platinum(II)

The photoinduced reductive elimination of cyanoalkanes (CH3CN, CH3CH2CN and CH3(CH2)2CN) from trans-hydridocyanoalkyl complexes of platinum(II), [PtH(R)(PPh3)2] (R = CH2CN, (CH2)2CN, (CH2)3CN) has been studied. The three trans complexes undergo isomerization to cis forms in the initial step before the reductive elimination. The elimination from the cis isomers is intramolecular as shown by the absence of crossover with the [PtH(CH2CN)(Ph2PCH=CHPPh2)] analogue and of the failure to detect the presence of free radicals during the reaction. The monomeric [Pt(PPh3)2] complex has been identified as the initial product of reductive elimination. Several reactions of this mechanistically important compound are also described.