Can Aromatic π-Clouds Complex Divalent Germanium and Tin Compounds? A DFT Study

Abstract

The properties of various electron-deficient germylenes and stannylenes are investigated using density functional theory (DFT). The dominant electrophilic character of these divalent group IV compounds is demonstrated by computed DFT-based reactivity descriptors. Next, the interaction of selected model dihalogenated germylenes and stannylenes (GeX2 and SnX2, with X = F, Cl, Br, I) with a series of potential aromatic π-donors is studied; computed classical donor–acceptor σ-interactions with strong Lewis bases serve as a reference. In addition, natural bond orbital analyses were performed in order to study the interactions at the orbital level, consistently indicating that the most important interaction for the π-complexations is the overlap of the formal empty p-orbital on the germanium or the tin atom and the π-orbitals of the aromatic rings. Additional information is obtained from the extent of charge transfer from the π-donors toward the divalent tin and germanium compounds. The existence of a complexat...