Pyrolysis of ortho-cyanotoluene and PCl3 mixtures:: the millimeter and submillimeter-wave spectrum of NCCCCP

The unstable NCCCCP molecule has been detected in the pyrolysis products of phosphorus trichloride and ortho-cyanotoluene mixtures. Its rotational spectrum has been investigated in the millimeter and submillimeter-wave regions for the ground and various vibrationally excited states which approximately lie below 400 cm(-1), namely (nu(8), nu(9)) = (0, 1), (0, 2), (0,3)1(0,4), (1, 0), and (1, 1). Transitions up to J = 241 <-- 240 were measured for the ground state, making a precise evaluation of the sextic centrifugal distortion constant possible. The l-type resonances between the different sublevels of the bending states have been taken into account in the analysis of the spectra, which yielded accurate determinations of the x(L(99)) and x(L(89)) anharmonicity constants. (C) 2003 Elsevier Inc. All rights reserved.