Hybrid Supramolecules for Azolium-Linked Cyclophane Immobilization and Conformation Study: Synthesis, Characterization, and Photocatalytic Degradation.

Abstract

In this paper, one imidazole macrocyclic divalent cation with a flexible configuration was chosen with the aim of the immobilization of its conformation. Six novel organic–inorganic hybrid supramolecules {([syn/anti-did](CdI4)(C2H3N)} (1), {([syn/anti-did](HgI4)(C2H3N)} (2), {([syn/syn-did](Pb2I8)(PbI5)} (3), {([syn/syn-did](Bi2I8)(BiI5)} (4), {([syn/syn-did](Ag4Br6)}n (5), and {([syn/anti-did](Ag2I4)} (6) [did2+ = (12z, 52z)-11H, 51H-1, 5(1, 3)-diimidazol-3-iuma-3, 7(1, 2)-dibenzenacyclooctaphane-13, 53-diium] have been synthesized through the self-assembly reaction of did2+ with different metals under solvothermal reaction. These compounds have been unambiguously confirmed by powder X-ray diffraction, IR, thermogravimetric and X-ray single-crystal diffraction. Crystallographic analysis shows that the anions of compounds 1 and 2 are isostructural with mononuclear anion structure, the anions of compounds 3, 4, and 6 are of binuclear structure, and compound 5 anion is a one-dimensional anionic chain structure. Imidazole cyclophanes of organic cations may exist in a syn/syn-conformation in 3–5 or syn/anti conformation in 1, 2, 6, but tilting angles in compounds 1–6 were different. This article described the photocatalytic degradation of organic dye in waste water and the optical band gap of compounds 1–6. The calculated semiconductor band gap of compounds 1–6 is smaller than that of TiO2, so compounds 1–6 have semiconductor properties. Compound 1 has the smallest band gap value, and the photocatalytic performance is the best.