Studies via X-ray analysis on intermolecular interactions and energy frameworks based on the effects of substituents of three 4-aryl-2-methyl-1H-imidazoles of different electronic nature and their in vitro antifungal evaluation.

The crystal structures of 2-methyl-4-phenyl-1H-imidazole, CHN, (3a), 4-(4-chlorophenyl)-2-methyl-1H-imidazole hemihydrate, CHClN·0.5HO, (3b), and 4-(4-methoxyphenyl)-2-methyl-1H-imidazole, CHNO, (3c), have been analyzed. It was found that the electron-donating/withdrawing tendency of the substituent groups in the aryl ring influence the acid-base properties of the 2-methylimidazole nucleus, changing the strength of the intermolecular N-H...N interactions. This behaviour not only influences the crystal structure but also seems to have an important effect on the antifungal activity. Considering the substituent groups, that is, H in (3a), Cl in (3b) and OMe in (3c), the formation of strong N-H...N connections has the probability (3a) > (3b) > (3c), while compound (3c) proves to be more active than (3a) and (3b) at all concentrations against C. neoformans.