Mid-infrared FTIR spectra of argon matrix isolated selenoketene-d(0) a
nd selenoketene-d(1) have been recorded. These transient species were
prepared by flow thermolysis of the corresponding 1,2,3-thiadiazoles.
With the aid of ab initio predictions of the vibrational frequencies a
nd intensities, six of the nine fundamentals have been identified for
each isotopomer. The spectra are dominated by a very intense C-C stret
ching band; the other fundamentals are significantly weaker and more d
ifficult to assign.