THE HIGH-RESOLUTION INFRARED-SPECTROSCOPY OF CYANOGEN DI-N-OXIDE (ONCCNO)

The high-resolution infrared absorption spectrum of the oxalodinitrile di-N-oxide (ONCCNO) molecule has been recorded in the gas phase with a Fourier transform spectrometer at a resolution of 0.003 cm(-1). No p revious high-resolution spectra have been recorded for this semistable palindromic molecule. On the basis of the 2:1 intensity alternation i n the rotational lines caused by nitrogen nuclear spin statistics, the ONCCNO molecule appears to be linear. A quasilinear structure, howeve r, cannot be ruled out at this stage of the analysis. The nu(4) and nu (5) fundamental modes at 2246.040 55(23) cm(-1) and 1258.475 30(11) cm (-1) have been analyzed to give ground state rotational constant of B- 0 = 0.042 202 10(96) cm(-1) and D-0 = 8.77(70) X 10(-10) cm(-1). By fi xing the CN and NO bond lengths to 1.1993 and 1.1730 Angstrom, respect ively, the C-C bond length was determined to be 1.3329 Angstrom using the B-0 value. This short C-C bond length is thus similar to that obse rved for a carbon-carbon double bond. (C) 1995 American Institute of P hysics.