The Fundamental Vibrations of NC-CC-CN (Dicyanoacetylene).

In the infrared spectrum of dicyanoacetylene the rotation vibration bands nu1 - nu9/2nu5 - nu9, nu1 + nu9/2nu5 + nu9 (Fermi resonance), nu2 - nu9, nu2 + nu8, nu4, nu6 - nu9, nu6 + nu8 - nu6, nu4 - nu7, nu4 + nu7, nu4 + nu7 - nu7, nu7 + nu8 - nu7, and 2nu7 + nu8 - nu7 (I and II) have been recorded with high resolution. From these bands the vibrational levels v1 = 1, v2 = 1, v4 = 1, v6 = 1, and v7 = 1 including the corresponding effective rotational constants have been calculated. Different methods for calculating the unperturbed position of the v1 = 1 level have been compared and the unperturbed B1 has been calculated. Additional information on the rotational constants of v8 = 1 and v9 = 1 is also given. Copyright 1997 Academic Press. Copyright 1997Academic Press