Dynamics of 1,3-dipolar cycloaddition reactions of diazonium betaines to acetylene and ethylene: bending vibrations facilitate reaction.

Getting the bends: The dynamics of 1,3-dipolar cycloaddition reactions have been explored by decomposing transition vector, quasi-classical trajectories, and single trajectories. Dipole bending (see picture) makes the largest contribution to the TS distortion energy and constitutes the major part of transition-state distortion energy in the favored concerted pathway.