2-n-Butyl-5-chloro-3H-imidazole-4-carbaldehyde (BCIC), C8H11ClN2O. F.W. = 186.64, monoclinic, P2(1)/c, a = 7.2617(3) Angstrom, b = 13.2067(6) Angstrom, c = 9.8491(4) Angstrom beta = 101.76(1)degrees, V = 924.74(7) Angstrom(3), Z = 4, D-cal = 1.341 Mgm(-3), mu = 0.367 mm(-1), F-000 = 392, lambda (MoKalpha) = 0.71073 Angstrom, final R1 and wR2 are 0.049 and 0.126, respectively. 2-n-Butyl-4-chloro-1 [(2'-cyanobiphenyl-4-yl)methyl]-5-hydroxymethyl imidazole (BCCI), C22H22ClN3O, F.W. = 379.88, triclinic, P (1) over bar, a = 8.198(2) Angstrom, b = 10.997(3) Angstrom, c = 11.524(2) Angstrom, alpha = 90.83(2)degrees, beta = 94.31(2)degrees, gamma = 109.45(2)degrees, V = 976.0(2) Angstrom(3) , Z = 2, D-cal = 1.293 Mgm(-3), mu = 1.856 mm(-1), F-000 = 400, lambda (CuKalpha) = 1.5418 Angstrom, final R1 and wR2 are 0.081 and 0.239, respectively. The imidazole ring in both the molecules is planar. The n-butyl group adopts a bent conformation in BCIC where it is in extended conformation in BCCI. The biphenyl ring system orients at an angle of 45.1(1)degrees in BCCI. The molecules are stabilized by N-H...N and O-H...N type hydrogen bonds in addition to van der Waals forces.