Rovibrational spectra of the N2-HF complex at the vHF=3 level

We report the analyses of the three intermolecular combination bands of the hydrogen-bonded N-2-HF complex at v(HF) = 3, observed by molecular beam intracavity laser induced fluorescence. The origin of the HF intermolecular bending combination band, (3001(1)0)<-(00000), is 11548.45(3) cm(-1), 328.2 cm(-1) higher than that of the (30000)<-(00000) transition with an origin at 11 220.250(1) cm(-1). The average rotational constant of the (3001(1)0) level is 0.103 63 (1) cm(-1), a 4.8% reduction from B(30000) = 0.109 21(1) cm(-1). Perturbations are observed as line splittings, increased line widths, and reduced peak intensities of a number of lines of the e and f components of (300110). In addition, the centrifugal distortion coefficients of both components are large, negative, and different. The N-2 intermolecular bend transition (30001(1))->(00000) has an origin at 11 288.706(1) cm(-1), 68.456(2) cm(-1) above that of the (30000)<-(00000) transition. This is the lowest combination state at v(HF) = 3 level. It is unperturbed, yielding B(30001(1)) = 0.110.10(1) cm(-1). The transition to the intermolecular stretching state, (30100)<-(00000), has an origin at 11 318.858(1) cm(-1) with B(30100) = 0.10584(1) cm(-1). Both the (30100), and (30000) levels show an isolated perturbation at J=4. The Lorentzian component of the line widths, which show considerable variation with soft mode, are Gamma(L)(30000) = 490(30) MHz, Gamma(L)(30100) = 630(30) MHz, Gamma(L)(3001(1)0) = 250(30) MHz, and Gamma(L)(30001(1)) = 500(50) MHz. (c) 2006 American Institute of Physics.