Oxidative ring contraction of 2-phenyl-1,3-dithiane in ZSM-5: restricted mobility of 1,2-dithiolane radical cations in zeolite channels
Abstract
Incorporation of 2-phenyl-1,3-dithiane 1 into ZSM-5 generated 1,2-dithiolane radical cation 2·+, the EPR spectrum of which shows an orthorhombic powder pattern (g1 = 2.0293, g2 = 2.0193, g3 = 2.0030); each g component showed a 1:4:6:4:1 pattern (a1 = 10.5, a2 = 9.3 and a3 = 9.2 G) due to coupling to four equivalent 1H nuclei, suggesting that the pseudo-axial and –equatorial α-protons undergo conformational equilibration whereas the sulfur centers are held stationary on the EPR time scale.