Construction And Properties Of Crown Ether Clathrates、Flexible Tetrazole And Flexible Carboxylate Polymers

The complexes assembled from in situ [2+3] cycloaddition tetrazole and muli-carboxylic acid ligands are of attractive potential applications in many fields of functional molecular materials, such as catalysis、fluorescence、adsorption and magnetism. The protonated R-NH3+ cation(R=aryl ring) is easily anchored in the cavity of 18-crown-6, which is a good molecular stator or pendulator in molecular machine design. In this paper, four tetrazole complexes、 seven carboxylate-transition metal complexes and two clathrate compounds from crown ether were synthesized, we implemented single-crystal X-ray diffraction, infrared spectra, elemental analysis, thermogravimetric analysis, powder X-ray diffraction analysis, fluorescence spectra analysis, differential scanning calorimetry(DSC) measurements, dielectric constant—temperature curve test to research their properities of structure、catalysis、fluorescence、phase transition、dielectric、ferroelectric etc.In chapter 1, a brief introduction of coordination chemistry and crystal engineering are presented. Illustrate the concept of spontaneous resolution, the catalytic application of copper- tetrazole complexes, the discover and development of tetrazole complexes、carboxylic complexes and crown ether clathrate compounds, include structural features、coordinational models and practical properties. The research significance and main results of this thesis are also summarized.In chapter 2, the first enantiomers Δ- and Λ- of metal tetrazole compound [Cu(Tzmp)]n(1)(HTzmp = 3- tetrazolemethyl pyridine) were obtained and isolated from in situ [2+3] cycloaddition reactions of a flexible organic nitrile(3-cyanomethyl pyridine) with sodium azide in the presence of Cu Cl2 as Lewis acid. Δ-1 and Λ-1 feature a homochiral {4(4).6(2)} two-dimensional framework. The photoluminescent study suggests 1 exhibit strong green fluorescent in solid state with maximal emission peak around 535 nm. 1 shows effective catalyze activity on the Herry reaction between 4-nitrobenzaldehyde and nitromethane, can significantly improve the yield to more than 96%.In chapter 3, three complexes with different coordinated anions were synthesized by in situ [2+3] cycloaddition reactions and. X-ray diffraction structural analysis reveals that they have the same equivalent nodes but with dissimilar topologies. Complexes 2 and 3 are isomorphism which have an acentric 3D framework with(10, 3)-b net called “ths”, while complex 4 has a distinctive 2D framework with Shubnikov hexagonal plane net. Photoluminescent study suggest 2, 3 and 4 exhibit strong green fluorescent in solid state with maximal emission peaks around 460, 470 and 444 nm respectively.In chapter 4, Four new mixed-ligand coordination polymers 5-8 have been synthesized under hydro(solvo)thermal conditions. X-ray single crystal structure analysis shows that 5 and 6 are isomorphic and possess a linear chain. 3 is also a linear chain without coordinated water molecules in the structure. 4 is an unusual 2D structure constructed by a binuclear cadmium building block. It appears that the chelate ligands and metal ions of the larger size favor the formation of high-dimensional structures, whereas those of the smaller size favor the formation of low-dimensional structures in the present system. The solid-state ?uorescences pectra of 7, 8 and free pamoic acid show that 7 and 8 exhibit a greatly enhanced emission compared to free pamoic acid ligand, which originated from intraligand(π-π*) transitions.In chapter 5, three transition metal complexes(9-11) were synthesized by hydrothermal reaction with major ligand 2,2’-azanediyldibenzoic acid and second ligands 4,4’-bipyridine(bpy) and pyridine(py). These polymers show great differences in regard to their structures and properties originated from the variation of second ligands and coordination geometry of the metal ions. Compound 9 exhibits a 3D supramolecular network assembled from 2D layered architecture composed of dinucelar cadmium subunits via intermolecular π···π and C–H···π interactions. The supramolecular structure of compound 10 is built from the packing of two homochiral helical chain. Compound 11 possesses two crystallographical nonequivalent metal atoms with Zn1 in four-coordinated tetrahedron geometry and Zn2 in five-coordinated trigonal bipyramid geometry. Five different coordination modes of major ligand ranging from μ2, μ3 and μ4 have been observed respectively. The solid-state ?uorescence spectra show that complexes 9 and 10 exhibit tiny blue shifts while 11 presents red shift compared to free ligand.In chapter 6, molecular motion is one of the structural foundations for the development of functional molecular materials such as arti?cial motors and molecular ferroelectrics. We synthesized two umbrella-like 18-crown-6 and cyclohexane clathrate compounds which crystallization in ferroelectric space group Pca2(1) and Cmc2(1) respectively. The differential scanning calorimetry(DSC) measurement and dielectric measurement exhibit abnormal peak around 398 K, and features first order phase transition of order-disorder type. The reason can be attributed to the order-disorder of 18-crown-6 or cyclohexane. This research opened a new avenue for the design of polar functional materials.