Electron Paramagnetic Resonance Spectroscopic Characterization of α,2- and α,4-Didehydrotoluene

Abstract

The elusive diradicals α,2- and α,4-didehydrotoluene 1 and 3, have been generated by photolysis of matrix-isolated 2-iodobenzyl iodide 7 and 4-iodobenzyl iodide 8, respectively. Diradical 3 could also be synthesized by flash vacuum thermolysis of 8, with subsequent trapping of the products in argon at 5 K. The diradicals in their triplet ground states were characterized by electron paramagnetic resonance spectroscopy. The triplet ground states were in accordance with previous theoretical calculations for these species.