STRUCTURE AND BONDING IN A SERIES OF CYANO COMPLEXES - RUCP(PPH3)(2)CN, [RUCP(PPH3)(2)(CNH)]CF3SO3, AND H-BRIDGED [RU-2(CP)(2)(PPH3)(4)CNHNC]CF3SO3

The three title cyanoruthenium complexes have been characterized by me ans of X-ray diffraction analysis, IR and NMR solution spectroscopies, as well as extended Huckel molecular orbital calculations examining t he properties of the cyanide fragment changing with complexation and w ith the co-ligands Cp and PPh3. Explanations are given for crystallogr aphic results of the C-N bond shortening upon complexation, the supers hort (2.573 Angstrom) bond length of N(H)... N in the bridged complex, as well as the Ru-C-N and C-N-H-N-C bendings. Although the crystallog raphically found asymmetry of coordinated Cp is not significant, the M O calculations suggest a distorted endocyclic bond-length pattern indi cative of the relative importance of sigma and pi bonding in the metal cyclopentadienyl interactions.