Synthesis of new heterodinuclear aminocarbyne complexes: crystal structures of [AuW{µ-CN(Et)Me}C6F5)(CO)2(η-C5H5)] and [{CuW{µ-CN(Et)Me}Cl(CO)2(η-C5H5)}2]

Abstract

The aminocarbyne [W{CN(Et)Me}(CO)₂(cp)]1(cp =η-C₅H₅) reacts with [Au(C₆F₅)(tht)](tht = tetrahydrothiophene) and CuCl to give the adducts [AuW{µ-CN(Et)Me}(C₆F₅)(CO)₂(cp)]2 and [{CuW{µ-CN(Et)Me}Cl(CO)₂(cp)}₂]3 respectively which have been structurally characterized by X-ray diffraction. Complex 2 crystallizes in space group P, a= 9.840(5), b= 11.577(6), c= 8.296(6)Å, α= 99.03(5), β= 91.01(6), γ= 81.92(4)°, Z= 2. Complex 3 crystallizes in space group P2₁/a, a= 7.788(2), b= 14.880(5), c= 11.712(5)Å, β= 95.35(3)°, Z= 2. Both adducts exhibit a molecule of 1 bonded to Au(C₆F₅) or Cu₂Cl₂ fragments, respectively, through one of the W–C(carbyne)π bonds. A WCM ring is formed in which 1 preserves most of its identity and the coinage metals attain their preferred electron counts. The cationic Group 11 fragments [M(PPh₃)⁺](M = Cu, Ag or Au) also react with complex 1 to form [M{W[µ-CN(Et)Me](CO)₂(cp)}₂]⁺5; when M = Au NMR spectroscopy indicates that in addition to the trinuclear species 5, the dimetallacyclopropene [AuW{µ-CN(Et)Me}(CO)₂(cp)(PPh₃]⁺4 is also present. All these adducts have been spectroscopically characterised.