SUBMILLIMETER-WAVE ROTATIONAL SPECTRA OF SO ISOTOPOMERS IN THE ELECTRONIC STATES A(1)DELTA AND B(1)SIGMA(+)

Pure rotational transitions of the sulfur monoxide isotopomers (SO)-S- 32-O-16, (SO)-S-34-O-16, and (32)S(18)0 were measured in different vib rational states of the electronic states a(1) Delta and b(1) Sigma(+) with the Cologne terahertz spectrometer in the submillimeter-wave regi on between 300 and 1070 GHz. The new lines were analyzed together with previous results from the literature in a global fit yielding isotopi cally invariant rotational parameters for both states. The measurement s reported here allowed for the first time the determination of the pa rameters U-01(S), and U-01(O) to correct for the breakdown of the Born -Oppenheimer approximation analogously to the X-3 Sigma(-) state. Prec ise equilibrium bond lengths gamma(e) are given for all states concern ed. (C) 1997 Academic Press.