A comparative rotational analysis of the 0(0)(0) bands of the (3)A(2)<-(X)over-tilde(1)A(1) Wulf transition for the isotopomers O-16(3) and O-18(3) of ozone by high resolution Fourier transform spectrome try

A high resolution Fourier transform spectrometry comparative analysis of th e rotational structure of the 0(0)(0) absorption band of the (3)A(2)<--(X) over tilde(1)A(1) Wulf transition for the isotopomers O-16(3) and O-18(3) O f the ozone molecule is presented. With a near pure case (b) coupling model for the upper triplet state, we identified, in these two rovibrational ban ds, numerous lines of sub-bands associated with the three F-1(N = J - 1), F -2(N = J), F-3(N = J + 1) spin components. Many superpositions around the o rigin, plus perturbations and predissociation phenomena limit our unperturb ed data set for the (3)A(2) State to less than 100 unperturbed rotational l ines in the range 9100-9550 cm(-1) for each band. Using for each of them th e well defined ground state parameters, we obtained a standard deviation of about 0.050 cm(-1) in the fits to the Lines. The rotational constants A, B , C, the three rotational distortion terms Delta(K), Delta(K), Delta(J), th e spin-rotation constants a(0), a, and b and the spin-spin constant alpha a re determined for the (0 0 0) vibrational level of the (3)A(2) State and of the two isotopomers. The parameter beta arbitrarily fixed for O-16(3) was successfully calculated for O-18(3) and this last result justifies the beta value adopted for O-16(3). The geometrical parameters of the (3)A(2). Stat e for the two isotopomers are close, r = 1.343 Angstrom, theta = 98.8 degre es for O-18(3) and r = 1.345 Angstrom, and theta = 98.9 degrees for O-16(3) . So are the Delta and kappa values. The origin of the O-18(3), OX band is blue Shifted by 20.6(4) cm(-1) with respect to the O-16(3) 0(0)(0) band. Fo r the congested parts of the spectra comparisons of both isotopic species h as to be done in a special way through sub-band contours. We justify the ex istence of perturbations in the first vibrational levels of the (3)A(2) sta te by several crossings with high vibrational levels of the ground state. ( C) 1999 Elsevier Science B.V. All rights reserved.