Structure, bonding and reactivity of coinage metal complexes TML2 and TML2+ (TM = Cu, Ag, Au) with planar tetracoordinate carbon, a theoretical investigation

The structures and bonding of the complexes TML2 and TML2+ with planar tetracoordinate carbons (TM = Cu, Ag and Au; L = C3H2BCH3 and C3Me2BCMe3) have been investigated using density functional theory M06 method, in which L are the derivatives of 2-borabicyclo[1.1.0]but-1(3)-ene. The lengths of Au-C and Ag-C bonds in AuL2 and AgL2 are longer than those of in TML2+, whereas the lengths of Cu-C bonds in TML2 are shorter than those of in TML2+. The NBO analyses of TML2 and TML2+ reveal that the Cu-C bonds in CuL2 are conjugated pi bonds, whereas Ag-C and Au-C in TML2 (TM =Ag and Au) are sigma bonds. The first electron transition energies of TML2+ result from the d-pi transition, and the wavelengths are close to 260 nm. Theoretically, the variations of the Gibbs free energies of the reactions of Ag (C3H2BCH3)(2)(+) and Ag(C3Me2BCMe3)(2)(+) with (tht)AuBr indicate that the two reactions are thermodynamically favorable. We also theoretically obtained the stable Au(III) complexes (C3H2BCH3)(2)AuBr2+ and (C3Me2BCM3)(2)AuBr2+ with planar tetracoordinate carbons from the reactions of Au(C3H2BCH3)(2)(+) and Au (C3Me2BCM3)(2)(+) with CsBr3. (C) 2015 Elsevier B.V. All rights reserved.