Hybrid Supramolecules for Azolium-Linked CyclophaneImmobilization and Conformation Study: Synthesis Characterizationand Photocatalytic Degradation

摘要

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.