THE PURE ROTATIONAL SPECTRUM OF LICH3((X)OVER-TILDE(1)A)

The pure rotational spectrum of lithium manomethyl, LiCH3, in its (X) over tilde(1)A ground electronic state has been measured using millime ter/sub-millimeter direct absorption techniques. Spectra of LiCD3 and (LiCH3)-Li-6 have been recorded as well. These species were synthesize d in the gas phase by the reaction of lithium vapor, produced in a Bro ida-type oven, and (CH3)(4)Sn, (CH3)(2)Hg or CH3I. Transitions were re corded in the 90-505 GHz range for J = 2 <-- 1 to J = 11 <-- 10 and K = 0 up to K = 10. Rotational and centrifugal distortion constants have been determined for each isotopomer, as well as an r(o) structure for LiCH3. (C) 1998 Elsevier Science B.V. All rights reserved.