Electronic spin resonance spectra of SiH3 radicals trapped in the low temperature matrix of nonmagnetic isotopes of xenon

Xenon enriched with nonmagnetic isotopes, in which the content of magnetic isotopes is less than 0.4%, has been used as the low temperature matrix for the observation of electronic spin resonance (ESR) spectra of SiH3 radicals and H atoms. The SiH3 radicals were generated by the reaction of SiH4 with H atoms produced by the photolysis of HI. Well resolved proton hyperfine structures, which were smeared out into a broad singlet spectrum when natural xenon was used as the matrix, were observed. The ESR parameters were determined by numerical deconvolution and compared with those obtained for the radicals trapped in other matrices. Simple doublet spectrum of H atoms without superhyperfine structures was also observed after the photolysis of HI at 4.2 K.