Fig. 5
1HNMR spectra of DCPD at various stages of reaction with sulfur: a After 10 min of reaction and, b at approximately the same stage of reaction, but under different conditions. Low temperature reactions were carried out at 135 °C, and high temperature at 185 °C. c Before reaction, the vinylic protons of DCPD appear at 5.5–5.9 ppm. d Reaction with sulfur yields S–C–H protons that appear in the 3.5–4 ppm region. e Proton substitution at the α position, without addition across the double bond, results in C=C(–H)–C–S proton environments that are shifted downfield w.r.t. their original positions, appearing at ~6.5 ppm
