VERY LOW PRESSURE PYROLYSIS (VLPP) OF MONOSILACYCLOBUTANES. INFRARED ABSORPTIONS OF 1,1-DIMETHYL-1-SILAETHYLENE, (CH3)2Si=CH2, AND 1,1-DIDEUTERIOMETHYL-1-SILAETHYLENE, (CD3)2Si=CH2 ISOLATED IN ARGON MATRICES

Article abstract of DOI:10.1016/S0022-328X(00)92572-5

The pyrolysis products of 1,1-dimethyl-1-silacyclobutane (DMSCB) and 1,1,3-trimethyl-1-silacyclobutane (TMSCB), and also of the Si-deuteriomethyl analogs (DMSCB-d₆ and TMSCSB-d₆) isolated in argon matrices at 10 K have been studied by IR spectroscopy.Pyrolysis of DMSCB and TMSCB gives rise to an identical set of bands: 644, 696, 817, 824, 932, 992, 1001 and 1253 cm^-1 which permanently vanish with the increase in temperature.Correspondingly, the bands at 543, 580, 683, 718, 722, 768, 891. 929, 985 and 1012 cm^-1 are observed in the spectra of pyrolysis productsof DMSCB-d₆ and TMSCB-d₆.The appearance of an identical set of bands is attributed to 1,1-dimethyl-1-silaethylene (DMSE) isolated in the argon matrix, but in the case of deuterio analogs, to DMSE-d₆.Based on normal coordinate treatment, the above mentioned bands have been preliminary assigned to certain modes of vibrations of DMSE and DMSE-d₆.