Knowledge Bank

The Stark spectra of several methanol isotopomers ($CH3OD,13CD3OH,CD3OH$, and $CD3OD$) have been investigated in the far-infrared region using the HCN and DCN lasers. The spectra were recorded at room temperature for both parallel and perpendicular polarizations using electric fields up to 60 000 V/cm. Numerous transitions have been observed with these laser lines for all isotopomers. The following transitions will be presented: for $CH3OD,IK=61\leftarrow 53F2\nu t=0,Jk=181\leftarrow 180E2\nu t=1,JK 14G\leftarrow 135A\nu t=1;$ for $\mathrm{<mrow\; data-mjx-texclass="ORD">13</mrow>}CD3OH,Jk=182\leftarrow 171A-\nu 1=0$; and for $CD3OH,JK=141\leftarrow 150E2\nu 1=1$. Analysis of the recently recorded FTFIR spectra for $CD3OD$ has yielded accurate zero-field frequencies belonging to the Q-branch multiplet for $K=11\leftarrow 10E2\nu t=0$. By combining these results with the previously reported Stark fields for the $J=11$ through 19 members, we have determined the electric dipole moment of this important molecular species for the first time.