Coordination Chemistry of Anionic Pnictogenylborane Compounds

Novel anionic metallacycles (6: [(1) W­(CO)4]; 7: ([(2) W­(CO)4])2; 8: [(3) W­(CO)4]; 9: [(4) W­(CO)4]; and 10: [(5) W­(CO)4]) were selectively synthesized from the reaction of the flexible anionic pnictogenylborane derivatives [M­(C12H24O6)]­[H2E-BH2-EH2] [E = P, M = Na (1); E = As, M = K (2)], [Na­(C12H24O6)]­[H2As-BH2-PH2-BH2-AsH2] (3), and [Na­(C12H24O6)­(thf)2]­[tBuHE-BH2-EHtBu] [E = P (4); E = As (5)], with [W­(CO)4(nbd)] (nbd = bicyclo[2.2.1]­hepta-2,5-diene). In addition, the reaction of 1, 4, and 5 with [Cu­(MeCN)4]­[BF4] leads to unique coordination assemblies of the general formula [Cu2Na2(RHE-BH2-EHR)4]n [E = P, R = H (11); E = P, R = tBu (12); E = As, R = tBu (13)]. The solid-state structure of compound 11 possesses an inorganic 3D scaffold with an adamantane-like repeating unit of Cu­(I) ions.