There are few examples of single-crystal structure determinations of gelators, as gel formation requires that the dissolved gelator self-assemble into a three-dimensional network structure incorporating solvent via noncovalent interactions rather than self-assembly followed by crystallization. In the solid-state structures of the isostructural compounds 4,4'-bis[5-(methoxycarbonyl)pentyloxy]biphenyl (BBO6-Me), CHO, and 4,4'-bis[5-(ethoxycarbonyl)pentyloxy]biphenyl (BBO6-Et), CHO, the molecules sit on a crystallographically imposed center of symmetry, resulting in strictly coplanar phenyl rings. BBO6-Me behaves as an organogelator in various alcohol solvents, whereas BBO6-Et does not. The extended structure reveals bundles of molecules that form a columnar superstructure. Framework-energy calculations reveal much stronger interaction energies within the columns (-52 to -78 kJ mol) than between columns (-2 to -16 kJ mol). The intracolumnar interactions are dominated by a dispersion component, whereas the intercolumnar interactions have a substantial electrostatic component.

The solid-state structure of 2-(4-hy­droxy­phen­yl)-1-[(4-hy­droxy­phen­yl)meth­yl]-5,6-dimethyl-1H-benzimidazole acetone disolvate exhibits O—H⋯N hydrogen bonds between benzimidazole units and O—H⋯O hydrogen bonds with one of the acetone solvate mol­ecules as the acceptor. Density functional theory is used to estimate the strength of the inter­actions.