Unlocking pedal motion of the azo group: three- and unexpected eight-component hydrogen-bonded assemblies in co-crystals based on isosteric resorcinols
作者:Kristin M. Hutchins、Shweta P. Yelgaonkar、Brittany L. Harris-Conway、Eric W. Reinheimer、Leonard R. MacGillivray、Ryan H. Groeneman
DOI:10.1080/10610278.2018.1435884
日期:2018.6.3
Co-crystallization of 3-phenylazopyridine (3PAzP) with dihalogenated resorcinols (res) 4,6-diX res (where: X=Cl, Br, and I) yields co-crystals that support molecular pedal motion in the crystalline state. The co-crystals are sustained by hydrogen-bonded assemblies, with the pattern of hydrogen-bonding drastically different based on the res. For 4,6-diCl res, an unexpected eight-component hydrogen-bonded assembly is realized, while three-component hydrogen-bonded assemblies are observed for 4,6-diBr res and 4,6-diI res. We show the co-crystallization approach to afford pedal motion in the azo core, while no such motion is present in the absence of a res. Pure 3PAzP packs to form a noncentrosymmetric herringbone structure.[GRAPHICS].