The optical and electron resonance spectra of SO₃^-

Abstract

The ionic radical SO3-has been identified in T-irradiated single crystals of sodium dithionate, sulphamic acid, potassium sulphamate, potassium amine disulphonate and potassium methane disulphonate. The electron resonance spectrum is a single line with an isotropic g factor of 2"004. The principal values of the ~3S hyperfine coupling tensor are 428, 314 and 316 Mc/s, from which the percentages of 3s and 3p character of the unpaired electron orbital are obtained, enabling a value of 111 ~ for the O-S-O angle to be deduced. Ultra-violet transitions at 2700 A and 2400 ~, were found for SO3-. A value of 104 for the extinction coefficient of the 2400 ~ band was measured. A comparison of spin populations between the isoelectronic species PO3 =, SOaand CIO3 is included.

Electron Spin Resonance of γ-Irradiated Taurine

“…The principal values of the 33S03-A-tensor are given in Table 1 and agree very well with those reported by Chantry et al (10). The tensor shows cylindrical symmetry and all three elements must have the same sign, otherwise the atomic 33S anisotopic coupling (2B) of 56 G would be exceeded.…”

“…In the present study at high gain and modulation amplitude the four weak isotopic lines due to 33S03-in 0.76% natural abundance were observed. The same downfield shift of the 33S hyperfine pattern relative to the single line of the 32S spectrum was found as that reported by Chantry et al (10). This effect is expected if second order terms are retained in the derivation of the line positions from the spin Hamiltonian (12).…”

“…Chantry et al (10) calculated the angle between the direction corresponding to the largest A-tensor element of SO3-and the two distinguishable C-S bonds in the host crystal of K2CH2(S03), and obtained the values 7 and 53". They considered it unlikely that the SO3-fragment would be grossly displaced from its position prior to irradiation and therefore selected the angle 7" as the one through which the SO3-axis moves on irradiation.…”

Free-radical chemistry of sulfite.

“…The unpaired spin on S03 has been c culated to be 62% on the sulfur and 13% on each of t oxygens (55,56). SO3-can be considered, therefore, a sulfur-centered radical.…”

Radiation Chemistry of Dithionates

“…Chantry et al (1) found a single absorption line with a g value of 2.004 in the e.s.r. spectra of gamma irradiated single crystals of sodium dithionate.…”