High resolution infrared spectroscopy of cyanogen N-oxide, NCCNO

We report here on the first high resolution infrared absorption spectra of the semistable nitrile oxide, NCCNO. All of the fundamental modes of vibration (except for the lowest-frequency bending mode) and several combination bands have been measured with a Fourier transform spectrometer at a resolution of 0.005 cm(-1). In this paper, we present analyses of upsilon(4), the C-C stretching mode at 714.753 94(6) cm(-1), upsilon(6) the NCC bending mode at 403.925 97(6) cm(-1), upsilon(6) + upsilon(7) at 490.123 62(6) cm(-1), and the tentatively assigned upsilon(5) + upsilon(6) combination band at 826.291 86(8) cm(-1). A simultaneous least squares fit of these four bands gives ground state rotational constants of B-0 = 0.077 085 54(34)cm(-1) and D-0 = 4.570(30) x 10(-9) cm(-1). (C) 1996 American Institute of Physics.