Synthesis and characterization of a mercury-containing trimetalloboride.

The reaction of phenylmercuric chloride with an anionic dimanganese borylene (Li(+)[Cp2(CO)4Mn2B](-)) led to the formation of a trimetalloboride featuring the first reported bond between mercury and a non-cluster boron atom. Examination by (199)Hg NMR indicated (11)B-(199)Hg scalar coupling. Theoretical calculations indicated the nature of bonding to be σ-donation from a B-Mn π-orbital to Hg, in conjunction with weak Hgd→π* back-donation.