Free radical mechanism for photoinduced isonitrile-nitrile isomerization in solution

The photoinduced isomerization reaction in benzene solution from RNC to RCN was found to follow a free radical chain mechanism, where R represented -C (CH3)(3), -CH(CH3)(2), -CH3, -CH2CH3, and -CH2CH2CH3, respectively. The alk yl radical intermediates R. in the isomerization reaction were detected by electron spin resonance (ESR) spectroscopy in combination with spin traps P EN and ND. Initiation of the isomerization in condensed-phase can be explai ned by a homolytic bond breaking between R group and nitrogen atom in the p hoto-irradiated isonitrile derivatives at room temperature. The products an alysis by CC was also supported the conclusion of free radical chain mechan ism. (C) 1999 Elsevier Science S.A. All rights reserved.