Microwave Spectrum of Ethyl Isothiocyanate

Abstract

Abstract The microwave spectrum of ethyl isothiocyanate, CH3CH2NCS, has been obtained in the frequency region from 8.5 to 35 GHz. The spectrum identified is attributed to the cis configuration, namely, the methyl group eclipses the isothiocyanato group. The rotational constants for the ground vibrational state obtained are A=1419±10, B=1799.27±0.02 and C=1612.14±0.02 MHz. The dipole moment of this rotamer is μtotal=3.33±0.03 D (μa=3.33±0.03 D, μb=0.07±0.02 D). Two sets of vibrational satellites were observed and assigned to the modes of C–N torsion (58±30 cm−1) and CNC bending (107±30 cm−1).