Laser spectroscopic detection of the simplest unsaturated silylene and germylene

Heavy atom analogs, silylidene, H2C=Si and germylidene, H2C=Ge are not well known, although theoretical studies show that silylidene is the global minimum on the H2CSi potential surface. The production of jet-cooled H2C=Si and H2C=GE was undertaken, by striking an electric discharge in tetramethylsilane (TMS) or tetramethylgermane (TMG) vapour. Silyidene showed evidence of intensity anomalies in the LIF spectra.