Far-Infrared Laser Magnetic Resonance Spectroscopic Study of the ν2 Bending Fundamental of the CCN Radical in Its X̃2Πr State

Abstract

Bending vibration–rotation transitions between the (010) μ2Σ− and (000) 2Πr vibronic states of the CCN radical in its ground electronic state have been observed using far-infrared laser magnetic resonance (FIR LMR) spectroscopy. Thirteen FIR laser lines were used to record 769 resonances. The LMR data, combined with previous data, were used to determine vibrational, Renner–Teller, fine-structure, rotational, hyperfine, and molecular g-factor parameters using a least-squares fitting routine. The model used was an N2 effective Hamiltonian modified to include the Renner–Teller effect explicitly in a 2Π electronic state. The band origin for the (010) μ2Σ− ← (000) X̃2Πr transition was determined to be 179.598176 ± 0.000067 cm−1. The spin–orbit splitting in the ground state was refined and the complete set of 14N-hyperfine parameters determined for the first time.