Enhancing σ/π-type copper(i)thiophene interactions by metal doping (metal = Li, Na, K, Ca, Sc).

The influence of metal doping on σ/π-type copper(i)thiophene interactions and the nature of Cuπ/S bonding have been investigated. Our calculated results show that Li, Na, K, Ca and Sc atom doping on thiophene enhances the copper(i)thiophene interactions. Enhancement factors are determined by the electrostatic potential of the thiophene molecular surface and the electronic configuration of the doping metal. The more negative the electrostatic potential, the stronger is the interaction. The influence of the d-block transition metal element (Sc) is larger than that of s-block main group metal elements. Both the σ and π type Cuthiophene interactions are of moderate strengths and display partial covalent characters. Linear relationships exist between the topological properties (ρ(rc), ∇(2)ρ(rc), δ(A, B) and Hc) at the BCP and the bond lengths d(Cuπ/S). When the Cuπ/S bond length became shorter, larger ∇(2)ρ(rc), δ(A, B) and smaller Hc values can be predicted, resulting in greater covalent character of Cuπ/S bonding.