Hyperfine Constants and Nuclear Shieldings from the Microwave Spectra of FBO, ClBO, and FBS

✍ Scribed by Bethany Gatehouse; Holger S.P. Müller; Michael C.L. Gerry

• Publisher: Elsevier Science
• Year: 1998
• Tongue: English
• Weight: 291 KB
• Volume: 190
• Category: Article
• ISSN: 0022-2852
• DOI: 10.1006/jmsp.1998.7565

✦ Synopsis

Rotational spectra of the unstable molecules FBO, ClBO, and FBS have been measured in the 8-26 GHz frequency range using a pulsed jet cavity Fourier transform microwave spectrometer. The samples were prepared by passing electric discharges through mixtures of O 2 /BF 3 , O 2 /BCl 3 , or OCS/BF 3 , respectively, entrained in Ne. Hyperfine structures in the observed transitions have been resolved and analyzed in terms of nuclear quadrupole, spin-rotation, and spin-spin interactions. The quadrupole and spin-rotation coupling constants have been used to show that the electronic environment surrounding the boron nucleus of all three species is very similar. The spin-rotation constants have been used to determine, for the first time, experimental average shieldings of the Cl, F, and B nuclei of these molecules. Ab initio values for the nuclear shielding parameters have been calculated for comparison.