Construction Of Coordination-driven Superamolecular Nano-hybrid Systems And Their Application In Catalysis And Sensing

In recent several decades, research on nanomaterials has always been one of the most attracting topics of chemistry and materials science. The coordination driven organic-inorganic hybrid materials are also attracting more and more attention. But the micro- even nano-sized organic-inorganic hybrids remained relatively researched less until recently. So along with kinds of organic-inorganic hybrids of different dimensions are being reported, we should take much more care on how to downsize these materils to improve their so many well-known properties and applications. Specially, we usually take care properties on catalysis, sensing, proton conducting, drug delivery and bioimaing, and so.In this article, we designed and synthesized a series of organic ligands with special coordination geometry, and researched the self-assembly chemistry with metal ions systematically. At last we choose several coordination driven self-assemblies as organic catalysts, photocatalysts or chemical sensors for HCl gas.â… . A self-assembled nano-sized Pd₆L₈（L = 1, 3, 5-tris（4’-pyridyloxadiazole）-2, 4, 6-triethylbenzene） ball was constructed based on a new oxadiazole-containing tripod. In H₂O/Et OH mixed-solvent system, Pd（II）-ball displays excellent performance in Suzuki-Miyaura cross-coupling reactions at low catalyst loading under ambient conditions in homogeneous way. Furthermore, it shows heterogeneous catalyst nature in o-xylene and can be reused without loss of catalytic activity.â…¡. A Cu₄I₄-MOF（1）, which was readily prepared by a tri-armed ligand L and Cu I in solution, was reported. Single-crystal analysis indicated that 1 is a 4-connected sra framework consisting of Cu₄I₄ node and tri-armed oxadiazole-bridged ligand L. It can be a highly sensitive and selective, first of its kind, naked-eye and luminescence response sensor for detecting HCl gas under ambient conditions. The visual and luminescent detecting limits on the micro-sized of 1 are 3.2 and 1.6 ppb, respectively. The sensing mechanism was explored in detail, and it was proven to be a I/Cl exchange reaction on Cu₄I₄ cluster core followed by an in situ iodide oxidation and molecular iodine trapping procedure based on 1. The ion exchange between solid and gas phase on MOFs has not been reported so far and the remarkable reactivity of Cu₄I₄ cluster with HCl（g） in the presence of O₂ is also quite uncommon. Such exclusive response material is intensely desired during practical applications. Furthermore, the resulted I₂（?）Cu（I）-MOF species was demonstrated to be an effective heterogeneous catalyst for the synthesis of bis（indolyl）methanes in high yields.â…¢. Cd（Ⅱ）-MOF-based ternary composite materials of Cd S@Cd（Ⅱ）-MOF@TiO₂ were prepared by a unique TiO₂ induced gel-to-crystal approach. CdS@Cd（Ⅱ）-MOF@TiO₂ was demonstrated to be a highly active photocatalyst for hydrogen production under visible light based on water photolysis.â…£. Materials of noble metal nanoparticles loaded on MOFs were prepared through a balanced anions doping method on a Cd（Ⅱ）-MOF. The method we developed here represents one of most easily implemented ones in synthesizing this kind of materials and can be applied to other MOFs with balanced anions. The prepared catalysts were evaluated by the reaction of 4-nitrophenol reduction.â…¤. Ligands based on fullerene with C1-C4 alkyls were synthesized and used to assembly with Cu Br. The structures of coordination polymers obtained were obviously affected by the length of the alkyl and little organic solvents in the hydrothermal process. The catalytic abilities of lewis acid sites of CuBr₂^- and Cu₂Br₄^2- were compared in the reaction of methanolysis of phenylethylene oxide.In conclusion, the construction of coordination driven supramolecular systems is of great significance. The most important aspect now should be their potential applications in social daily life along with study of their colorful properties.