Abstract
The infrared spectrum of gaseous CH3I has been investigated in the range 500–16 500 cm−1, up to six quanta of excitation in CH stretching. A total of 16 perpendicular bands lying above 3700 cm−1 have been analyzed, some as Fermi resonance diads, in order to determine accurate vibrational wave numbers for the constituent levels. The local mode model has been applied to the CH stretching manifold to account for anharmonicity and the effects of Darling–Dennison resonances. Vibrations not involving CH stretching have been treated in a normal mode basis. The joint approach, which also takes into account known Fermi resonances, enables a complete set of 27 vibrational anharmonicity parameters to be determined for CH3I which fits 63 observed vibrational levels up to V=6 with a root-mean square (rms) error of 2.75 cm−1.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
