Preparation and Structural Characterization of [CpRu(1,10‐phenanthroline)(CH 3 CN)][X] and Precursor Complexes (X=PF 6 , BAr F , TRISPHAT‐N)

Cationic [Ru(η 5 ‐C 5 H 5 )(CH 3 CN) 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 (PF 6 − and BAr F − ) and coordinating TRISPHAT‐N − anions are reported. Complex [CpRu(η 6 ‐naphthalene)][BAr F ] ( [1][BAr F ] ) is readily accessible, in high yield, by direct counterion exchange between [1][PF 6 ] and sodium tetrakis[3,5‐bis(trifluoromethyl)phenyl]borate (NaBAr F ) salts. Ligand exchange of [1][BAr F ] in acetonitrile generated stable [Ru(η 5 ‐C 5 H 5 )(CH 3 CN) 3 ][BAr F ] ( [2][BAr F ] ) complex in high yield. Then, the desired [CpRu(Phen)(CH 3 CN)] ( [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][PF 6 ] , to quantitatively generate the desired complex [CpRu(Phen)(TTN)] ( [4] ) by displacement of the remaining acetonitrile ligand and of the PF 6 − anion. Solid state structures of complexes [1][BAr F ] , [2][BAr F ] , [3][BAr F ] , [3][PF 6 ] and [4] were determined by X‐ray diffraction studies and are discussed herein.