Knowledge Bank

The microwave spectra of substances having the general formula RNCO have been measured in the frequency region 8 - 200 $GHz$. These include particularly isocynic acid, HNCO, for which spectra have been measured for molecules isotopically substituted artificially at N, C, and O; and chlorine isocyanate, $C\ell CNO$, for which the spectra of three isotopic species have been measured. The spectra have yielded values for the rotational constants, inertial defects and nuclear quadrupole coupling constants, and internuclear parameters have been determined. Comparison of the structures with those of related molecules will be made.