Cobalt(II) coordination polymers built on isomeric dipyridyl triazole ligands with pyromellitic acid: Synthesis, characterization and their effects on the thermal decomposition of ammonium perchlorate

Abstract

Three new cobalt(II) coordination compounds, [Co(3,3′-Hbpt)2(H2pm)(H2O)2]·2H2O (1), [Co(4,4′-Hbpt)(pm)0.5(H2O)]·3H2O (2) and [Co(3,4′-Hbpt)(pm)0.5(H2O)3]·2H2O (3) (3,3′-Hbpt = 3,5-bis(3-pyridyl)-1H-1,2,4-triazole; 4,4′-bpt = 3,5-bis(4-pyridyl)-1H-1,2,4-triazole, 3,4′-Hbpt = 3-(3-pyridyl)-5-(4′-pyridyl)-1H-1,2,4-triazole and H4pm = pyromellitic acid) have been synthesized by hydrothermal reactions. Single-crystal X-ray diffraction reveals that compound 1 has a one-dimensional (1D) chain network, 2 exhibits a four-connected three-dimensional (3D) structure with 1D open channels encapsulated by water molecules, while 3 displays a regular two-dimensional (2D) architecture connected through 1D metal helical chains. In addition, the efficacy of compounds 1–3 as additives to promote the thermal decomposition of ammonium perchlorate (AP) is explored by differential scanning calorimetry (DSC).