I am working on the reaction of DMSO and NBS to form bromosulfoxonium cation and succinimide counteranion, I've gotten a complex, but all my effort to get a transition state proves abortive, i tried calculating in Triplet state as well cos of the succinmide counteranion but it was all abortive, so i carrried out and NBO analysis on the complex and the charge distribution is as follows NBS(N=-0.613, Br=0.295) and DMSO(O=-O.956, S=1.210) I'm trying to make a bond btw NBS -Br and DMSO -O