The differing influence of halides upon supramolecular aggregation through C–X⋯π interactions in the crystal structures of (5-methyl-1-(4-X-arylamino)-1H-1,2,3-triazol-4-yl)methanol derivatives, X = H, F and Cl

Abstract

The presence of localised C–X⋯π [or C–X⋯π(CC)] interactions are shown to be pivotal in the crystal structures of (5-methyl-1-(4-X-arylamino)-1H-1,2,3-triazol-4-yl)methanol derivatives, X = H (1), F (2) and Cl (3). In the absence of halide (1), molecules aggregate into supramolecular chains via alternating ten-membered {⋯HOC₂N}₂ and 14-membered {⋯HN₂C₃O}₂ synthons. Molecules assemble into a three-dimensional architecture via edge-to-face C–H⋯π(arene) interactions occurring between the phenyl rings. In the presence of halide (i.e. F (2) and Cl (3) in the 4-position of the phenyl ring), two-dimensional arrays are formed by interconnected ten-membered {⋯HOC₂N}₂ (as seen in 1) and 24-membered {⋯HO⋯NC₂OH⋯N₄H}₂ hydrogen bonded synthons. The latter arrangement allows for the close approach of halide to the 1,2,3-triazole ring and the formation of C–X⋯π interactions which appear to be particularly significant in the case of Cl (3), as evidenced by systematic changes (i.e. elongation) in the geometric parameters within the five-membered ring. In this series of structures, the presence of C–X⋯π interactions is shown to moderate the supramolecular aggregation based on conventional hydrogen bonding.