Carbon–arsine and Carbon–antimony Bonds Activation of AsPh3 and SbPh3 at Dimanganese and Dirhenium Centers in Bimetallic Complexes
摘要
The reactivity of [M2(CO)8(NCMe)2] (M = Mn, Re) with EPh3 (E = As, Sb) has been illustrated. Bimetallic manganese-arsenic complexes, [Mn2(CO)7(µ-AsPh2)(AsPh3)(µ-H)] (1) and [Mn2(CO)8(µ-AsPh2)2] (2) were produced from the reaction of [Mn₂(CO)8(NCMe)2] with AsPh3 in toluene at 110 °C. The controlled experiment shows that 1 is a precursor of 2. It can be speculated that activation of one phenyl group from the coordinated AsPh3 of 1 formed a second bridging (µ-AsPh2) ligand. The cleaved phenyl group most probably combines with the departed edge-bridging hydride to produce benzene as a byproduct. In contrast, a similar reaction with SbPh3 gave [Mn2(CO)8(µ-SbPh2)2] (3) as the sole product. On the other hand, identical reaction of [Re₂(CO)8(NCMe)2] and AsPh3 resulted a new type of rhenium-arsenic bimetallic complex [Re2(CO)5(σ-Ph)(µ-MeCO2)(µ-AsPh2)2] (5) along with two previously reported hydride compounds [Re2(CO)6(AsPh3)2(µ-AsPh2)(µ-H)] (4) and [Re(CO)4(AsPh3)H] (6). The coordination mechanism of the µ-MeCO2 ligand is unknown, as its source is unpredictable. However, we believe that the three-electron donor µ-MeCO2 ligand is formed by hydrolysis of a coordinated MeCN ligand by moisture. Molecular structures of the new products 1, 3, and 5 were unambiguously established through spectroscopic data and single-crystal X-ray diffraction studies. The bonding in these new complexes has been examined by density functional theory (DFT) calculations.
Graphical AbstractCarbon–arsine and carbon–antimony bonds activation of AsPh3 and SbPh3 at dimanganese and dirhenium centers in bimetallic complexes.