Synthesis and Reactivity of Diborane(4)yl Complexes

Abstract

Reaction of various 1,2-dihalodiboranes(4) with Na[(η5-C5H4R)M(CO)3] yielded the diborane(4)yl complexes [X(Me2N)B-B(NMe2){ η5-(C5H4R)M(CO)3}] (5, X = Cl, R = H, M = Mo; 6, X = Br, R = Me, M = Mo; 7, X = Br, R = H, M = W ;8, X = Br, R = Me, M = W )and [Cl(C4H8N)B-B(NC4H8){ η5-(C5H5)W(CO)3}] (9). The reactivity of diborane(4)yl complexes of the type [X(Me2N)B-B(NMe2){η5-(C5H5)M(CO)n}] (X = Cl, Br; M(CO)n = Fe(CO)2, Mo(CO)3) with respect to substitution of X and CO, respectively, was investigated. The novel derivatives [MeO(Me2N)B-B(NMe2){η5-(C5H5)Mo(CO)3}] (10), [MeO(Me2N)B-B(NMe2){η5-(C5H5)Fe(CO)2}] (11), and [Br(Me2N)B-B(NMe2){η5-(C5H5)- Mo(CO)2(PMe3)}] (12) were obtained. All compounds were fully characterised in solution by NMR spectroscopy and by elemental analysis.