Side-on coordination of boryl and borylene complexes to cationic coinage metal fragments.

The M-(η-BMn) complex [(η-CH)(OC)Mn{μ-B(Cl)(Bu)Au(PPh)}] () can be functionalized halide substitution reactions to afford isostructural complexes [(η-CH)(OC)Mn{μ-B(R)(Bu)Au(PPh)}] (R = Ph, CCPh and NCS). It also reacts with coinage metal complexes [MCl(PPh)] (M = Au, Ag and Cu) in the presence of halide abstraction reagents to afford borylene-bridged heteromultinuclear complexes [{(η-CH)(OC)Mn}{μ-B(Bu)}M][BArx4] (M = Au, Ag and Cu; Ar = 3,5-CHCl, 3,5-CH(CF)). Experimental characterization as well as computational studies revealed that these complexes are best viewed as transition metal borylene complexes side-on coordinated to monovalent coinage metal cations, thus representing the first boron analogs of Stone's alkylidyne-bridged multinuclear complexes.