Cu(I) Complexes Comprising tetrahedral Mo₂E₂ or Mo₂PE units (E=P, As, Sb) as Chelating Ligands

Abstract

Novel isomorphous tetranuclear complexes, [(dppf)Cu( μ 3 , η 2:2:2 ‐E2{CpMo(CO)2}2]BF4 [E = P (1), As (4), Sb (5), (dppf = 1,1′‐bis‐(diphenylphosphino)‐ferrocene)] and [(dppf)Cu( μ 3 , η 2:2:2 ‐PE{CpMo(CO)2}2]BF4 [E = As (2), Sb(3)] were synthesized from the reactions between [(dppf)Cu(MeCN)2][BF4] and tetrahedral molybdenum complexes containing unsubstituted homo‐ and hetero‐diatomic group‐15 elements [( μ , η 2:2 ‐E2{CpMo(CO)2}2] [E = P (A), As (D), Sb (E)] and [( μ , η 2:2 ‐PE{CpMo(CO)2}2] [E = As (B), Sb (C)], respectively. In all these products, the {Mo2E2} or {Mo2PE} moieties coordinate the Cu(I) center via a rare side‐on η 2 ‐coordination mode. The X‐ray structure analyses of [(dppf)Cu(μ3,η2:2:1‐PSb{CpMo(CO)2}2][BF4] demonstrate, for the first time, the utilization of an η 1 ‐coordination mode for the ligand complex C to coordinate to the Cu(I) center. All the products were characterized by X‐ray crystallography, NMR and IR spectroscopy, mass spectrometry and elemental analysis. Electrochemical studies also revealed the formation of 1‐5, and, further, to understand the structure and bonding of the products, theoretical calculations using density functional theory (DFT) were conducted.

Potential of Mixed Dipnictogen Molybdenum Complexes in the Self-Assembly of Thallium Coordination Compounds

“…Hence, our group studied the coordination chemistry of the homoleptic congeners [{CpMo­(CO) 2 } 2 (μ,η 2:2 -P 2 )] ( A ), ,, [{CpMo­(CO) 2 } 2 (μ,η 2:2 -As 2 )] ( D ) , and [{CpMo­(CO) 2 } 2 (μ,η 2:2 -Sb 2 )] ( F ) , in detail during the last years. Regarding the more elaborate heterodiatomic complexes [{CpMo­(CO) 2 } 2 (μ,η 2:2 -PE)] (E = As ( B ), Sb ( C )), only few reports on their coordination toward CuX (X = Cl, Br, I), (dppf)Cu (dppf = 1,1′-bis­(diphenylphosphino)-ferrocene) and M­[TEF] (M = Ag, Cu) as well as on their oxidation chemistry , are known. Their coordination behavior varies due to the different relative energies of the pnictogen lone pairs and the respective σ­(E–E′) bonds.…”