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 BAr_F^?) and coordinating TRISPHAT-N^? anions are reported. Complex CpRu(η⁶-naphthalene)]BAr_F] ( 1]BAr_F] ) is readily accessible, in high yield, by direct counterion exchange between 1]PF₆] and sodium tetrakis3,5-bis(trifluoromethyl)phenyl]borate (NaBAr_F) salts. Ligand exchange of 1]BAr_F] in acetonitrile generated stable Ru(η⁵-C₅H₅)(CH₃CN)₃]BAr_F] ( 2]BAr_F] ) 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]BAr_F] , 2]BAr_F] , 3]BAr_F] , 3]PF₆] and 4] were determined by X-ray diffraction studies and are discussed herein.