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

摘要

The M-(η²-BMn) complex [(η⁵-C5H5)(OC)2Mn{μ-B(Cl)(tBu)Au(PPh3)}] (>2) can be functionalized via halide substitution reactions to afford isostructural complexes [(η⁵-C5H5)(OC)2Mn{μ-B(R)(tBu)Au(PPh3)}] (R = Ph, CCPh and NCS). It also reacts with coinage metal complexes [MCl(PPh3)] (M = Au, Ag and Cu) in the presence of halide abstraction reagents to afford borylene-bridged heteromultinuclear complexes [{(η⁵-C5H5)(OC)2Mn}2{μ²-B(tBu)}2M][BArx4] (M = Au, Ag and Cu; Ar^x = 3,5-C6H3Cl₂, 3,5-C₆H₃(CF₃)₂). 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.