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)

摘要

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; 5a,b: 4,4'-dimethyl-2,2'-bipyridine; have been developed. Compounds 2a and 5a are produced from reactions of cis-Ru(tpy)-(CO)_2(CH_3CN)~(2+)2PF_6~- (9) with the appropriate bipyridine. Their linkage isomers, 2b and 5b, are produced by thermolysis of 2a and 5a. Procedures are described for the sodium 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 havebeen characterized by X-ray crystallography. The possible intermediacy of some of these compounds in catalytic reductions of CO_2 leading to glyoxylic or glycolic acid is discussed.