Imidazolium Phenolates

Abstract

1,3-Diisopropyl-4,5-dimethylimidazolium phenolate (4a), pentafluorophenolate (4b), and pentachlorophenolate (4c) are obtained from 2,3-dihydro-1,3-diisopropyl-4,5-dimethylimidazol-2-ylidene (2) and the corresponding phenols 3 as stable crystals in excellent yields. The crystal structure analyses of compounds 4 reveal the presence of ion pairs linked by almost linear C-H・・・O hydrogen bonds. With 4-hydroxypyridine (5), the carbene 2 gives 1,3-diisopropyl-4,5-dimethylimidazolium 4- pyridinolate (6) whose crystal structure analysis indicates the ions to be connected by a C-H・・・N bond.