Microwave spectrum, barrier to internal rotation, and dipole moment of SiF3 BF2

✍ Scribed by T. Ogata; A.P. Cox; D.L. Smith; P.L. Timms

• Publisher: Elsevier Science
• Year: 1974
• Tongue: English
• Weight: 522 KB
• Volume: 26
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(74)85393-5

✦ Synopsis

Thr microwzwe spectrum of za3iF31' BF2 has been studied in the frequency range 24-40 GHz. hnelysis of the bxv r'e bllrrier spectrum is complicated by the presence of the heavy SiFs top. A computer treatment has been developed based on an iAM es outlined by Wilson et al. A non-periodic Mathieu equation is solved to allow the rotational energy matrix to be set up. Torsionai leveis are specified by quantum numbers V and D = 0, ?I, t2 and 3.

-4bout 40 lines belonging to J = 8 -+ 9 through 13 -14 transitions were assigned and analyscd by the foregoing treiltment. The barrier hcighr was determined as V6 f 1.9 -e 0.8 calfmol. Rotations1 constants were determined to bcA(BF;) = 10373 2 30,3 = 1504.90 t 0.05 and C= 1314.79 + 0.03 MHz. These constmts lead to an Si-B bond length significiantly larger than that expected for a sir&e bond, a result consistent with the extremely low barrier v&m_ Stark effect me;lsuremcnts, with nn analysis severely complicated by internal rotation, give the dipole moment JC = 1.09 r 0.05 D,