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)Cl₅]^{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 ² coordination of NO gets slightly smaller if ligand L possesses -acceptor properties.