Preparation and Structural Characterization of [CpRu(1,10‐phenanthroline)(CH3CN)][X] and Precursor Complexes (X=PF6, BArF, TRISPHAT‐N)

Cationic [Ru(η5‐C5H5)(CH3CN)3]+ complex, tris(acetonitrile)(cyclopentadienyl)ruthenium(II), gives rise to a very rich organometallic chemistry. Combined with diimine ligands, and 1,10‐phenanthroline in particular, this system efficiently catalyzes diazo decomposition processes to generate metal‐carbenes which undergo a series of original transformations in the presence of Lewis basic substrates. Herein, syntheses and characterizations of [CpRu(Phen)(L)] complexes with (large) lipophilic non‐coordinating (PF6− and BArF−) and coordinating TRISPHAT‐N− anions are reported. Complex [CpRu(η6‐naphthalene)][BArF] ([1][BArF]) is readily accessible, in high yield, by direct counterion exchange between [1][PF6] and sodium tetrakis[3,5‐bis(trifluoromethyl)phenyl]borate (NaBArF) salts. Ligand exchange of [1][BArF] in acetonitrile generated stable [Ru(η5‐C5H5)(CH3CN)3][BArF] ([2][BArF]) complex in high yield. Then, the desired [CpRu(Phen)(CH3CN)] ([3]) complexes were obtained from either the [1] or [2] complex in the presence of the 1,10‐phenanthroline as ligand. For characterization and comparison purposes, the anionic hemilabile ligand TRISPHAT−N (TTN) was introduced on the ruthenium center, from the complex [3][PF6], to quantitatively generate the desired complex [CpRu(Phen)(TTN)] ([4]) by displacement of the remaining acetonitrile ligand and of the PF6− anion. Solid state structures of complexes [1][BArF], [2][BArF], [3][BArF], [3][PF6] and [4] were determined by X‐ray diffraction studies and are discussed herein.