Reactions of Acetonitrile Coordinated to a Nitrosylruthenium Complex with H₂O or CH₃OH under Mild Conditions: Structural Characterization of Imido-Type Complexes

The reaction of cis-[Ru(NO)(CH3CN)(bpy)2]3+ (bpy = 2,2‘-bipyridine) in H2O at room temperature proceeded to afford two new nitrosylruthenium complexes. These complexes have been identified as nitrosylruthenium complexes containing the N-bound methylcarboxyimidato ligand, cis-[Ru(NO)(NHC(O)CH3)(bpy)2]2+, and methylcarboxyimido acid ligand, cis-[Ru(NO)(NHC(OH)CH3)(bpy)2]3+, formed by an electrophilic reaction at the nitrile carbon of the acetonitrile coordinated to the ruthenium ion. The X-ray structure analysis on a single crystal obtained from CH3CN−H2O solution of cis-[Ru(NO)(NHC(O)CH3)(bpy)2](PF6)3 has been performed: C22H20.5N6O2P2.5F15Ru, orthorhombic, Pccn, a = 15.966(1) Å, b = 31.839(1) Å, c = 11.707(1) Å, V = 5950.8(4) Å3, and Z = 8. The structural results revealed that the single crystal consisted of 1:1 mixture of cis-[Ru(NO)(NHC(O)CH3)(bpy)2]2+ and cis-[Ru(NO)(NHC(OH)CH3)(bpy)2]3+ and the structural formula of this single crystal was thus [Ru(NO)(NHC(OH0.5)CH3)(bpy)2](PF6)2.5. The reaction of cis-[Ru(NO)(CH3CN)(bpy)2]3+ in dry CH3OH−CH3CN at room temperature afforded a nitrosylruthenium complex containing the methyl methylcarboxyimidate ligand, cis-[Ru(NO)(NHC(OCH3)CH3)(bpy)2]3+. The structure has been determined by X-ray structure analysis: C25H29N8O18Cl3Ru, monoclinic, P21/c, a = 13.129(1) Å, b = 17.053(1) Å, c = 15.711(1) Å, β = 90.876(5)°, V = 3517.3(4) Å3, and Z = 4.