Metastable states of ruthenium nitrosyl complexes. Density functional quantum-chemical calculations

Geometry optimization for the ground state and metastable isomers of the nitrosyl complexes trans-[Ru(NO)(NH3)(4)(L)](3+) (L = imidazole, pyridine, pyrazine, nicotinamide), [Ru(NO)(CN)(5)](2-), and [Ru(NO)Cl-5](2-) was performed in terms of the density functional theory (SVWN/LanL2DZ + 6-31G). The energy gap between the stable structure and the isomer with linear coordination of NO via the oxygen atom is practically independent of the nature of ligand L in the series of ammonia complexes with the same charge, and the energy gap between the stable structure and the isomer with side 112 coordination of NO gets slightly smaller if ligand L possesses pi-acceptor properties.