The Role of Ligands in Oxidative Addition Chemistry of Low-Valent Main Group Derivatives: Not Only Stabilization but Also Activation

Abstract

At present, the use of low-valent derivatives of the main group elements, including metallylenes, etc., in catalysis as an alternative to transition metals is widely discussed. The high reactivity of these compounds often requires their stabilization by using electron-pair donor ligands. The influence of the latter on oxidative addition reactions is usually not considered. In this work, to the best of our knowledge for the first time, using the example of the oxidative insertion of Lappert’s germylene into PhSSPh in the presence of N, S, P, and O donor ligands, we show that the ligands significantly increase the reaction rate. This can be associated with an increase in the level of the germylene highest occupied molecular orbital under the influence of a donor. Qualitatively, the obtained values of the reaction rate constants correlate well with the germylene oxidation potentials in the presence of ligands or ligand oxidation potentials.

Derivatives of penta-, hexa-, and hepta-coordinated tin with Schiff bases and 1,10-phenanthroline: structure, redox and optoelectronic properties

“…The examples include the dramatic decrease in the reduction potential and the increase in the availability of LUMO of germanium derivatives in the presence of N-donors, 2–4 the preparation of D⋯A-layered structures based on germanium complexes with 2,3-dihydroxynaphthalene and N , N ′-bidentate ligands with a narrow HOMO/LUMO gap (∼2 eV), 5 the fine tuning of the germylene HOMO level in the presence of N, S, P, and O-donor ligands, which determines the ability of germylenes to participate in oxidative addition reactions. 6,7 The key methods in the listed studies of germanium coordination compounds are voltammetry and UV-vis spectroscopy, which, when used in combination, make it possible to experimentally quantify the position of the frontier orbitals of the substrate.…”