Spectroscopic detection of the stannylidene (H₂C=Sn and D₂C=Sn) molecule in the gas phase

The H₂CSn and D₂CSn molecules have been detected for the first time by laser-induced fluorescence (LIF) and emission spectroscopic techniques through the B̃¹B₂-X̃¹A₁ electronic transition in the 425-400 nm region. These reactive species were prepared in a pulsed electric discharge jet using (CH₃)₄Sn or (CD₃)₄Sn diluted in high-pressure argon. Transitions to the electronic excited state of the jet-cooled molecules were probed with LIF, and the ground state and low-lying ùA₂ state energy levels were measured from single vibronic level emission spectra. We supported the experimental studies by a variety of ab initio calculations that predicted the energies, geometries, and vibrational frequencies of the ground and lower excited electronic states. The spectroscopy of stannylidene (H₂CSn) is in many aspects similar to that of silylidene (H₂CSi) and germylidene (H₂CGe).