The Synthesis And Crystal Structure Research Of Novel Crown Ether Coordination Compounds

Crown ether is a kind of synthetical receptor, and the study of it is still of ongoing interest for more than thirty years. It is a challenge for people to design more highly selective crown ether for single metal ions. If substituting group is connected with the benzo-ring of crown ether, the selectivity of crown ether can be increased due to electronic effects of unbonding isolated electrons in the hetero-atoms and steric factors. In this way, crown ether has new chemical reactions and compounding characteristics, its water-solubility and toxicity are greatly decreased, and its field of application is enlarged. In this thesis, ten crown-ether thiosemicarbazone ligands and thirty coordination compounds were synthesized and characterized. The crystal structures of representative ligand L¹ and its NaBPh₄ complex were determined by X-ray diffraction.This kind of ligands can be better coordinated with metal ions because of the concerted effect between crown ether ring and thiosemicarbazone group. Furthermore, they are also excellent bifunctional receptors as thiourea moieties have better recognition ability to anions.The first chapter includes the research progress of crown ether compounds and ion recognition and a brief review of crystal structures of benzo-15-crown-5 sodium compounds and the applications of crown ether compounds.In the second Chapter, ten crown-ether thiosemicarbazone ligands and thirty coordination compounds were synthesized and characterized by element analysis, IR and 'HNMR, etc. The ten ligands are 4'-Acetylbenzo-15-crown-5 thiosemicarbazone (L¹) and N⁴-aryl-4'- Acetylbenzo-15-crown-5thiosemicarbazone(L^2-10.L^2-10L²: R = H; L³: R = 2-CH₃; L⁴: R = 3-CH₃; L⁵: R = 4-CH₃;L⁶: R = 2-CH₃O; L⁷: R =4-CH₃O; L⁸: R = 4-C1; L⁹: R = 4-F; L¹⁰: R = 4-CH₃CH₂OC1-C4 and C5-C12 are sodium salt complexes and transition metal salt complexes of L¹ seperately. C13-C3O are silver nitrate and hydrous cadmium chloride complexes of L^2-10. The result showed that L¹ and sodium salt were formed of 1: 1 crown ether complexes. However, the sulfur atom of C=S group participated in the coordination in the transition metal salt compounds of L¹.In the third Chapter, the crystal structures of 4'-Acetylbenzo-15-crown-5 thiosemicarbazone(L¹) and its NaBPlu complex were analyzed. In the crystal structure of L¹, there were N-H...O and O-H...S intermolecular hydrogen bonds by which the L¹ formed supramolecular structure. In the crystal structure of C2, the sodium ion coordinated with sulfur atom of another complex besides the oxygen atoms of the crown ether. The adjacent complex cations formed a linear pqlymer via Na-S coordination bonds as show below. This kind of bonding has never been reported in the crystal structures of crown ether complexes...