Crystallography and magnetism of radicals with hindered hydroxyl groups: 2-(3,5-di-tert-butyl-4-hydroxyphenyl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-3-oxide-1-oxyl and 2-(3,5-di-tert-butyl-4-hydroxyphenyl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-1-oxyl

Abstract

Radicals 1–2 form networks of OH⋯ON and OH⋯Me(nitroxide) interactions. In 2, a frustrated network forms with insufficient N–O units to form extended chain interactions. The magnetism of 1 fits a 1-D Heisenberg model with J/k = −25 J mol⁻¹, while 2 shows more complex exchange behaviour consistent with its disordered crystal lattice.