Fine Structure of J=1←0 Transition due to Internal Rotation in Methyl Alcohol

The fine structure of J =1←0 lines in various isotopic species of methyl alcohol has been explained by a combination method of Itoh's theory for a rigid asymmetric hinded rotor and Kivelson's theory for a nonrigid symmetric hindered rotor. All lines have been fitted within errors of 2 Mc by this method. From the analysis the height of potential barrier to internal rotation for CH 3 OD has been determined to be 371±5 cm -1 . The molecular structure of methyl alcohol has also been calculated and discussed.