The kinetics of the quantitative, symmetry allowed, reverse electron demand cycloadditions of the pseudo-1,3-dipole SNS + with alkynes and nitriles; the preparation and X-ray crystal structures of NCCSNSCHAsF 6 and SNSNC–CNSNS(AsF 6 ) 2 : the precursor to a new class of S 2 N 2 C–CN 2 S 2 n+ (n= 0,1,2) bicyclics

The rates of cycloaddition reactions of SNSAsF6 with alkynes and nitriles increase as the ionization potential (Ei) of the triple bond decreases, and accordingly reaction with HCCCN occurs preferentially at the CC bond; however, it reacts with NCCN quantitatively to give the dication ([graphic omitted])22+, from which several members of a new family of S2N2C–CN2S2n+(n= 0,1,2) bicyclics have been prepared.