Knowledge Bank

Infrared spectra of gaseous and matrix isolated $CH3N:CHCH3$, $CD3N:CHCH3$ and $CH3N:CDCD3$ were measured in the region 4000 - $200cm-1$. The analysis of the spectra yielded an almost complete set of fundamental frequencies for the three isotopic species. Matrix spectra proved to be essential for the localisation of weak fundamentals, such as the methyl rocking modes. The assignment of the spectra will be discussed, with special emphasis on rotational contours and a number of Fermi- and Coriolis resonances detected in the regions of the methyl group vibrations.