THE NU(6)+N-NU(9) LEVELS OF DICYANOACETYLENE

In addition to the previously observed band system nu(6) + (n + 1)nu(9 )-n nu(9) with n = 0 to 7, Delta l = 0, and l = n near 611 cm(-1), we have identified the nu(6) + (n + 1)nu(9) - (n + 2)nu(9) system with n = 0 to 6, Delta l = 0, and l = n + 2 near 397 cm(-1). From these bands the rovibrational levels of the states (nu(6), n nu(9)) with n < 4 ha ve been determined and spectroscopic parameters have been obtained tak ing into account rotational and vibrational l-type resonances. Effecti ve anharmonicity constants x(69), and g(69) have been calculated also for levels with n greater than or equal to 4. (C) 1998 Academic Press.