Structural characterization,gelation ability,and energy‐framework analysis of two bis(long‐chain ester)‐substituted 4,4′‐biphenyl compounds

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′‐bis5‐(methoxycarbonyl)pentyloxy]biphenyl (BBO6‐Me), C₂₆H₃₄O₆, and 4,4′‐bis5‐(ethoxycarbonyl)pentyloxy]biphenyl (BBO6‐Et), C₂₈H₃₈O₆, 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^?1) than between columns (?2 to ?16 kJ mol^?1). The intracolumnar interactions are dominated by a dispersion component, whereas the intercolumnar interactions have a substantial electrostatic component.