Construction of interesting organic supramolecular structures with synthons cooperation in the cocrystals of 1H-benzotriazole and hydroxybenzoic acids

Multifunctional molecules are capable of assembling via different supramolecular synthons, or hydrogen bond motifs, between the same or different functional groups, leading to the possibility of cocrystal. Utilization of the interplay of dimensionality （I-D, 2-D and 3-D）, orientation of functional groups of the building blocks, influence of rigid/flexible linking groups, and weak interactions provides an interesting route for the creation of novel supramolecular architectures in the crystal lattice. N-unsubstituted 1H-benzotriazole and carboxylic acid, being self-complementary molecules, offer a broad scope of study of binary compounds based on the complementary combination of H-bonding/donating sites. We report here the construction of three extended molecular networks in cocrystals of the carboxylic acid group of the acid and the 1H-benzotriazole triazole moiety. We have been able to identify four major supramolecualr synthons that would be helpful in the prediction of structural motifs for these kinds of studies. Interestingly, these heterosynthons are strikingly similar, to those of the homosynthons of the individual functional groups. The nature of the aza groups helps to enhance the overall volume of the crystal lattice thus lead- ing to the formation of various supramolecular assemblies. Thermal stability of these compounds has been investigated by thermogravimetric analysis （TGA） of mass loss.