Knowledge Bank

The spectrum of the double internal rotor ethanol $(\nu OH=0,1,2\dots ;\nu CH3=0,1,2,\dots$ of internal rotation) has been studied in the millimeter-wave region. Approximately 200 lines have been assigned to the lowest trans state $(\nu OH(A)=0,\nu CH3(A,E)=0)$ and a few have been tentatively assigned to the lowest gauche states $(\nu OH(E+,E.)=0,\nu CH(A,E)=0)$. A three-fold internal rotor analysis of the methyl rotation in the trans state will be presented including previous $data1$. Formulation of a complete molecular $Hamiltonian2$ and the selection rules for the ground state $(\nu CH3=\nu OH=0)$ will be discussed.