Knowledge Bank

The infrared spectrum of methyl isocyanide, CH3NC, has been measured in the region $2120-2190cm-1$ at a resolution of $0.002cm-1$ using a Bomem $DA3$ Fourier-transform spectrometer. The $\nu 2$ fundamental band and two combination band. $\nu 2+\nu 8-\nu 8$ and $\nu 2+2\nu 8-2\nu 8$, have been assigned. Molecular constants for the upper states of the three bands have been derived using the ground state constants determined by microwave $spectroscopy1.2$ and fitting procedures and programs developed by $Plfva3$.