Supramolecular squarate and hydrogensquarate compounds with 4-amino-1,2,4-triazole, 2-aminothiazole and 2-aminobenzimidazole

Three organic amine squarate salts were synthesized and characterized by means of elemental analysis, FT-IR spectroscopy and thermal analysis (TG, DTG and DTA). The crystal structures of 4-amino-4H-1,2,4-triazolium hydrogenesquarate, (C2H5N4)(HC4O4) (I), bis(2-aminothiazolium) squarate dihydrate, (C3H5N2S)2(C4O4)·2H2O (II) and bis(2-amino-1H-benzo[d]imidazolium) squarate, (C7H8N3)2(C4O4) (III) have also been studied. They crystallizes in the monoclinic system, space group P21/c, C2/c and C2/c, respectively. The organic amine molecules link the squarate ions via N–H⋯O hydrogen bonds. All the organic amine squarates show similar decomposition behaviour and decomposed in two or three thermal stages.