Synthesis and characterization of formyl and hydroxymethyl complexes derived from isomeric cations: cis-Ru(N-N)(eta(2)-tpy)(CO)(2)(2+)2PF(6)(-) (N-N=2,2 '-bipyridine, 4,4 '-dimethyl-2,2 '-bipyridine; tpy=2,2 ': 6 ',2 ''-terpyridine)

High-yield syntheses of the novel cations cis-Ru(N-N)(eta (2)-tpy)(CO)(2)(2 +)2PF(6)(-) (2a,b: N-N = 2,2'-bipyridine, tpy = 2,2':6',2 " -terpyridine; 5 a,b: N-N = 4,4'-dimethyl-2,2'-bipyridine) have been developed. Compounds 2a and 5a are produced from reactions of cis-Ru(tpy)(CO)(2)(CH3CN)(2+)2PF(6)( -) (9) with the appropriate bipyridine. Their linkage isomers, 2b and 5b, a re produced by thermolysis of 2a and 5a. Procedures are described for the s odium borohydride reductions of 2a,b and 5a,b to the corresponding formyl ( 3a,b and 6a,b) and hydroxymethyl (4a,b and 7a,b) derivatives. Compounds 2a, 2b, 5b, and 4a have been characterized by X-ray crystallography. The possi ble intermediacy of some of these compounds in catalytic reductions of CO2 leading to glyoxylic or glycolic acid is discussed.