Dicoordinate copper(I) chalcogenides – Structure and bonding

Structure and bonding of H3PCuESiH3 and CuESiH3 complexes (E = O, S, Se) has been investigated using BP86 density functional (DF) calculations. Linear (∠(Cu–E–Si) = 180°) and bent (∠(Cu–E–Si) < 180°) coordination geometries have been considered. A detailed bond analysis reveals that Pauli repulsion represents the dominant interaction that characterizes the Cu–E bond. A reduction in Pauli repulsion is the major factor that favors a bent arrangement. An electron density analysis based on the localized orbital locator (LOL) further suggests that bending increases the covalency of the Cu–E bond.