Knowledge Bank

The microwave spectrum of $CD3ND2$ has been investigated in an effort to elucidate the structure of the methylamine molecule. A series of lines in which the rotational transition is of the type $JOJ\to J1J$ has been studied in the 24000-35000 Mc regions. Each rotational transition is split into four lines, with spacings of the order of 100 Mc, as a result of the internal motion. These splittings have been analyzed on the basis of a hindered internal rotor with additional terms to include the possibility of inversion of the $ND2$ group. Preliminary values for molecular constants are: reciprocal principal moments: 52420 Mc, 16550 Mc, 15570 Mc; quadrupole coupling constants: $\chi aa=2.4Mc,\chi bb=2.1Mc,\chi cc=-4.5Mc$; barrier to internal rotation: $Va=590$ $cm-1$.