ESR Study of 1,3-Phenylenebis(5-tert-Butyl-3-Phenyl-2-Phenylnitrene)

Abstract

1,3-Phenylenebis(5-tert-butyl-3-phenyl-2-phenylnitrene) ( m-4 ) was generated by photolysis of the corresponding precursor diazide m-3 in 2-MTHF at 3 K with a high-pressure Xe lamp, and its ESR spectrum was measured. The observed ESR spectrum was analyzed by computer simulation based on the eigenfield / exact diagonalization hybrid method to give two sets of zfs parameters: |D| = 0.323 cm⁻¹ and |E| = 0.016 cm⁻¹; |D| = 0.340 cm⁻¹ and |E|=0.011 cm⁻¹. The temperature dependence of ESR signal intensity of m-4 in the temperature region of 3–70 K was a linear relationship in the intensity vs reciprocal temperature plot, indicating that m-4 is in a quintet ground state.

Key Words:

• nitrene
• photolysis
• ESR
• quintet ground state