Stable bidentate silylene adducts of alkaline‐earth amides

Abstract

AbstractThe coordination chemistry of silylenes is known for a vast number of elements of all blocks of the periodic table. However, only a handful of examples of silylene complexes have been reported for heavy alkaline‐earth elements, which is mainly attributed to the “hard‐soft” mismatch between the “hard” metal center and the “soft” silicon donor. Herein, we report the synthesis and characterization of a series of alkaline‐earth silylene complexes comprising a bidentate pyridyl‐amido‐silylene ligand. The isolated Ca, Sr and Ba complexes show considerably increased stability in comparison to other known alkaline‐earth silylene complexes. The molecular structures of all three complexes are essentially similar. Interestingly, depending on the central metal, the 1H NMR chemical shifts of the ortho‐H atom show unexpected large differences. DFT computations were conducted to elucidate this trend in the NMR resonances.