High-Resolution Infrared Spectra of Cyanogen and Cyanogen-15N2

The infrared absorption of 12C214N2 and 12C215N2 has been studied with a resolution of 0.08 to 0.04 cm−1. The vibration—rotation band constants were determined for eight vibrational transitions of 12C214N2 and three vibrational transitions of 12C215N2. Many unresolved hot-band Q branches were also measured. The values for many vibrational and rotational constants are given. The bond distances determined from the rotational analysis, and their three-standard-deviation error limits, are r0 (C–C) = 1.389±0.030 Å and r0 (C≡N) = 1.154±0.017 Å. The N–N distance and corresponding error limits are 3.697±0.010 Å.