Knowledge Bank

Two fundamental vibrations at 1824.7 and $1159.5cm-1$ assigned previously on the basis of limited data to $C3H$ trapped in an Ar $matrix2$, have been the subject of an extensive $\mathrm{<mrow\; data-mjx-texclass="ORD">13</mrow>}C$ and deuterium isotopic investigation by Fourier transform infrared spectroscopy. The $C3H$ isotopomers wee produced by trapping the products of the vacuum ultraviolet (VUV) photolysis of either propylene ($CH2$$CHCH3$) or a mixture of acetylene ($C2$$H2$) and methane ($CH4$) with appropriate isotopic substitutions in Ar at 14 K. The possible linear and cyclic ($C2v$ and $Cs$ symmetries) isomeric structure for $C3H$ will be examined with respect to the observed isotopic shifts and the predictions of ab initio calculations.