Spectra of jet-cooled (SO2)-S-32 and (SO2)-S-34 in systems (a)over-tilde(3)B(1) and (b)over-tilde(3)A(2)-(X)over-tilde(1)A(1): Rotational structure of perturbed (b)over-tilde(3)A(2)

Spectra of (a) over tilde B-3(1)(nu (1)nu (2)nu (3))=(110) and (200)-(X) ov er tilde (1)A(1)(000) of (SO2)-S-32 and (SO2)-S-34 are obtained in a supers onic jet at a resolution 0.015 cm(-1). The rotational structures are analyz ed for both isotopic species to obtain precise rotational and spin constant s. Two new bands at 27 032.222(1) and 27 515.41(1) cm-1 arising from vibron ic interaction separately with vibrational state (110) and (200) of (a) ove r tilde B-3(1) are assigned to transitions to (b) over tilde (3)A(2)(011) a nd (101). The rotational structure of (b) over tilde (3)A(2) is observed an d analyzed for the first time. The two vibrational states are analyzed to y ield effective rotational constants A=1.4348(3), 1.89(3), B=0.3610(3), 0.41 2(3), and C=0.2689(3), 0.239(3) cm(-1), respectively. Then the difference n u (1)-nu (2) of vibrational frequency of (b) over tilde (3)A(2) is obtained to be 483.19 cm(-1). Because of interaction to (b) over tilde (3)A(2)(011) the observed spacing of K stack and spin constants alpha and beta for (a) over tilde B-3(1)(110) are smaller whereas the state (a) over tilde B-3(1)( 200) is relatively unaffected and only spin constants vary significantly. ( C) 2001 American Institute of Physics.