Heterosynthons in molecular complexes of azopyridine and 1,2-bis(4-pyridyl)ethylene with dicarboxylic acids

A series of co-crystals of azaaromatic molecule with the present of dicarboxylic acid, [SA(.)BPE], [FA(.)AZP], [AA(.)BPE], (AA(.)AZP], [SEA(.)AZP] and (OA(.)AZP] (BPE = 1,2-bis(4-pyridyl)ethylene, AZP = azopyridine, SA = succinic acid, FA = fumaric acid, AA = adipic acid, SEA = sebacic acid, OA = oxalic acid), have been synthesized for the regularity investigation of their supramolecular alignments driven by hydrogen bonding. It is significant for the design and synthesis of supramolecular co-crystals with multiple components. For linear molecules with recognition sites on both ends, the stacking regularity of the molecules in the co-crystals is proposed that the interlaced arrangement (motif III) is preferred when the size of the azaaromatic molecule is comparable with that of dicarboxylic acid and the inclined arrangement (motif II) is adopted when the length of azaaromatic molecule is much different from those of dicarboxylic acids. (C) 2003 Elsevier B.V. All rights reserved.