STERIC INTERACTIONS IN 2-SUBSTITUTED IMIDAZOLES - THE MOLECULAR-STRUCTURE OF 1-METHYL-2-PHENYLIMIDAZOLE AND 1-METHYL-4-PHENYLIMIDAZOLE

The crystal and molecular structures are reported for two isomeric imi dazoles: 1-methyl-2-phenylimidazole (1) and 1-methyl-4-phenylimidazole (2). In molecule 2 the phenyl ring is rotated by 7.3-degrees from the heterocyclic plane due to steric interactions. The steric congestion is much more severe in 1, with the adjacent methyl and phenyl substitu ents mininizing nonbonded interactions via a 32.3-degrees rotation of the phenyl ring and a 0.159 angstrom displacement of the methyl carbon from the heterocyclic plane.