Recent Advances in the Chemistry of Germanium(II) Cationic Compounds

Abstract

Abstract The syntheses and stabilizations of germanium(II) cationic compounds have been known for long. Contemporary research have been engaged in tailoring the germanium(II) cationic species for applications in small‐molecule activation and catalysis. This article comprises the discussion on the three major types of germanium(II) cationic compounds: (1) germanium(II) monocation or germyliumylidene, (2) bis(germyliumylidene), and (3) germanium(II) dication. Herein, earlier reports on the stabilization of germanium(II) mono‐ and dications have been briefly mentioned. The article includes the latest findings on the stabilization of the germanium(II) cationic species. The major focus of the article has been on discussing how the choice of the supporting ligands becomes the determining factor for tuning the frontier electronics and hence the applicability of the cationic germanium(II) compounds. Examples of bond activation at the ambiphilic germanium(II) monocationic sites and their catalytic applications, element–ligand cooperative bond activations, transition metal‐main group cooperative catalysis, reverse polarization at the germanium(II) cationic site, cooperative interactions between two germanium(II) cationic sites, leading to organic transformations, etc., which are some of the remarkable findings, have been discussed. This overview on the advancements made in this field will provide a background knowledge for further explorations.