2,2′-Dimethylbiphenyl-4,4′-dinitrene

Photolysis of 2,2′-dimethylbiphenyl-4,4′-diazide in a glassy matrix at 77 K gives first a mononitrene ESR peak (|D/hc| = 0.95 cm−1), followed by production of a lower field peak attributable to a twisted biphenyl-4,4′-dinitrene (|D/hc| = 0.93 cm−1), in which two nitrene moieties are electronically isolated from one another by torsion.