Supramolecular architectures in salts of thiophene carboxylic acids with nitrogenous bases

Predictions on supramolecular interactions are helpful for the design of novel active pharmaceutical products. Thiophene based compounds along with various nitrogeneous bases are used in the preparation of such multi-component crystalline materials. Single crystals of 5-fluoro cytosinium 3-chlorothiophene -2- carboxylate (compound I) and 5,5’- Dimethyl -2,2’-bipyridinium thiophene -2,5- dicarboxylate- thiophene -2,5-dicarboxylic acid (2:2:1) (compound II) were synthesized and the supramolecular interactions stabilizing their crystal structures were investigated. R₂ (8) supramolecular heterosynthon was observed in (I). N-H…O, C-H…Cl, F…π and Cl…π interactions were mainly observed in supramolecular architecture of compound I. Fluorine involving interactions were observed in larger abundance and they are highly directional. N-H…O, O-H…O, C-H…O, C-H…π and π…π interactions stabilizes compound II. Compound II is an example of a structure with symmetric hydrogen bond. Thiophene 2, 5- dicarboxylic acid coexisted in both neutral and mono-anionic form in compound II.