Silicon-carbonyl complex is stable at room temperature

Abstract

Transition metals are attractively reactive but can be expensive and toxic. For years, chemists have been probing the reactivity of main-group elements to provide suitable alternatives, but they have not had much luck making carbonyl complexes from non-d-block elements, presumably because of these elements’ lack of π back-bonding orbitals. Now, Stephan Schulz and coworkers at the University of Duisburg-Essen and Justus Liebig University Giessen have synthesized the first known silicon-carbonyl complex that’s stable at room temperature (Nat. Chem. 2020, DOI: 10.1038/s41557-020-0456-x). They were able to accomplish this by beefing up the silicon with two gallium β-diketiminate ligands, which are known to stabilize low-valent main-group complexes. The group then directly reacted CO with the electron-rich silylene in benzene at 60 °C to make the carbonyl complex in 30% yield. In the past, scientists have been able to isolate these compounds only under cryogenic conditions in solid argon. The new compound is