The title compounds, 1-ferrocenylmethyl-2-(4-methoxyphenyl)-1H-benzimidazole, [Fe(C5H5)(C20H17N2O)], (I), and 2-(3,4-dimethoxyphenyl)-1-ferrocenylmethyl-1H-benzimidazole, [Fe(C5H5)(C21H19N2O2)], (II), are model electroactive compounds for anion sensor and antimalarial applications. Distortions from the ideal 120 degrees angle about the MeO-C-C groups are evident, with angles of 115.1 (2) and 125.0 (2) degrees in (I), and 115.9 (2) and 124.6 (2) degrees, and 115.7 (2) and 125.1 (2) degrees in (II). The main intermolecular hydrogen bonds in (I) comprise C-H.N and C-H.pi(C5H5) interactions, while in (II), only weak C-H.pi(imidazole) and C-H.pi(arene) interactions are present.