Beschreibung:
<jats:p>The 617.7 and 614.7 nm bands of calcium monocyanide, CaNC/CaCN, have been recorded at high resolution by laser-induced fluorescence using a supersonic molecular beam. The two bands consist of twelve branches that are assigned to a case a (0,0,0)A 2Πr–(0,0,0)X 2Σ+ transition. A reduction of the data to an effective Hamiltonian model produced the spectroscopic parameters (cm−1): T00= 16229.5417(26), B″=0.13499(14), γ″=6.1837(33)×10−4, A′=77.6451(40), B′=0.15027(23), AD′=2.69(11) × 10−3, D′= −3.50(25) × 10−5, p′=0.0754(18), q′=−0.04808(87), qD′′= 2.64(65) × 10−5. It is proposed that the anomalous values of the excited state parameters arise because of Renner–Teller interactions. The magnitude of the permanent electric dipoles, |μ|, were also determined and are 5.949(1) D[A 2Π1/2(0,0,0),J= 0.5] and 6.895(9) D[X 2Σ+(0,0,0),J= 1.5]. The large value of |μ| is consistent with an isocyanide structure, CaNC. A comparison with theoretical predictions is presented.</jats:p>