Ruthenium tris(pyrazolyl)borate complexes. Formation and characterization of acetone, dimethylformamide and vinylidene complexes containing N,N-donor co-ligands

Abstract

Chloride abstraction from [Ru{HB(pz)3}(tmen)Cl](pz = pyrazolyl, tmen = Me2NCH2CH2NMe2) with NaBPh4 in the solvents acetone and dimethylformamide led to the formation of the respective cationic [Ru{HB(pz)3}(tmen)(solv)]+ complexes. In the presence of phenylacetylene, these are easily transformed into the first example of a ruthenium HB(pz)3 vinylidene complex. Extended-Hückel molecular-orbital calculations have been performed to establish the nature of the bonding involved. From [Ru{HB(pz)3}(py)2Cl](py = pyridine) the corresponding vinylidene complex could be prepared in the same way, although the intermediate solvent complexes could not be isolated. Selected crystal structures were determined.