Detection of the microwave spectrum of tricarbon oxide sulphide,C3OS

The microwave spectrum of tricarbon oxide sulphide (3-thioxo-1,2-propadiene-1-one), OCCCS, is shown to be that of a linear molecule with B_o = 1413.898 MHz and D_o = 0.046 kHz. The dipole moment was determined to be 0.634 debye. As a five-atomic linear molecule C₃OS has three degenerate bending modes, ν₅, ν₆, and ν₇. The l-type doubling constant for each of these modes was determined, and the vibrational frequencies have been estimated from these values and from relative intensity measurements.