摘要:
The pure rotational spectra of MgNC in the ν2 (bending) vibrationally excited states were observed in the 310–380 GHz region to study the linearity of the molecule. The observed 90 spectral lines were assigned to the transitions in the v2=1–5 states and analyzed to determine a set of molecular constants in each state. The bending vibrational frequency was estimated to be 86 cm−1 from the l-type doubling constant of the v2=1 state. The interval of the Φ and Π states in v2=3 was determined to be 29.2280(24) cm−1, giving the anharmonicity constant xll=3.8611(9) cm−1 with one standard deviation in parentheses, which indicates that the molecule has a linear form. However, somewhat peculiar properties were recognized in dependence of the observed l-type resonance and vibration-rotation constants on the v2 vibrational quantum number, suggesting an effect of anharmonicity.