Hydrogen bonded supramolecular network in organic salts: crystal structures of acid-base salts of dicarboxylic acids and amines

Four new organic salts, namely bis(2-aminopyridinium) fumarate-fumaric acid (1 : 1) 1, benzylammonium hydrogen fumarate 2, 2-aminopyridinium hydrogen cyclobutane-1,1-dicarboxylate 3 and benzylammonium hydrogen cyclobutane-1,1-dicarboxylate 4 have been synthesized and characterized by FT-IR, H-1 NMR and single crystal X-ray crystallography in order to analyse their supramolecular structures. While 1, 2 and 4 form two-dimensional layer structures, 3 displays a one-dimensional network. The role of stronger O-H...O and N-H...O interactions and weak C-H..O interactions on the supramolecular arrangement have been discussed based on the single crystal X-ray structures.