Octahedral manganese(i) and ruthenium(ii) complexes containing 2-(methylamido)pyridine-borane as a tripod κ3N,H,H-ligand.

Abstract

The borane adduct of the 2-(methylamido)pyridine anion, [mapyBH3]-, has been incorporated into octahedral metal complexes. In fac-[Mn(κ3N,H,H-mapyBH3)(CO)3] (1) and fac-[RuH(κ3N,H,H-mapyBH3)(CO)(PiPr3)] (2), which have been prepared by treating K[mapyBH3] with fac-[MnBr(MeCN)2(CO)3] and [RuHCl(CO)(PiPr3)2], respectively, it behaves as a tripod ligand, attached to the metal atom through the amido N atom and through two H atoms of the BH3 moiety. X-ray diffraction analyses and theoretical studies (DFT, QTAIM) have shown that the MH2B atom grouping of 1 and 2 comprises two 3c-2e M-H-B interactions that are between those of the Shimoi type (κ1H coordination of the B-H bond) and those of the agostic type (κ2B,H coordination of the B-H bond). However, while both M-H-B interactions are almost identical in complex 1, this is not the case in complex 2, in which one M-H-B interaction is more agostic than the other due to the different trans influence of the hydride and phosphane ligands.