2-(Difluoromethyl)benzimidazole, CAS number 705-09-9, is a fluorinated heterocyclic aromatic compound, consisting of a benzimidazole which is an imidazole fused with a benzene, and a difluoromethyl group at the 2-position. The amines in 2-(difluoromethyl)benzimidazole are nucleophilic and can easily attack an electrophilic center in other molecules for synthesizing dyes with larger chromophores. The amines can also coordinate to a metal center such as Cu2+ in application of DSSCs, in which charge recombination is efficiently slowed down.
The difluoromethyl substituent provides the lipophilicity to 2-(difluoromethyl)benzimidazole, improving the processability. The proton on the difluoromethyl group is more acidic than regular alkyl proton, due to the electron deficit of the two fluoro-groups on the adjacent carbon. This allows the carbon to be selectively deprotonated for further functionalization.