ASSIGNMENT OF METHYL CYANIDE FIR LASER LINES

In the literature, there are measurements for more than 30 FIR laser e missions of the CH3CN molecule, and in addition observations of 13 lin es for the deuterated species CD3CN. For many lines the assignments ha ve been proposed, but these are often based on old and relatively inac curate infrared spectra. Starting from a recent series of high resolut ion FTIR studies of these molecules in our laboratory, the assignments of these Fm laser lines have been studied. For CH3CN, accurate combin ation loops confirmed 14 previous assignments and checked seven new on es. In addition, a new idea for three lines has been provided. For CD3 CN, four old assignments has been confirmed. Five new detailed explana tions and two new tentative possibilities are presented here.