Syntheses, Structures And Properties Of Chiral Metal Coordination Complexes Based On Pyridine Derivative Ligands

Chiral metal coordination complexes have attracted dramatic attention, due to their fantastic topologies and applications in chiral separation and asymmetric catalysis. In recent years, the syntheses and applications of chiral metal coordination complexes have been achieved successfully. However, it is still a challenge to improve the performance of materials in chiral separation and asymmetric catalysis.Chirality of chiral metal coordination complexes origin from three aspects, chiral groups, chiral metal center, and supermolecular chirality. This dissertation included two parts, syntheses of chiral ligands and assemblies of chiral metal coordination complexes, and syntheses of chiral iridium(Ⅲ) complexes.Natural chiral carboxylic acid compounds as the easily available and generally cheap starting chiral materials are widely used in the field of constructing chiral metal coordination complexes, due to ready derivatives and rich bonding recognition sites. In the first part, we introduced proline and (1S)-(-)-camphanic acid as the starting chiral compounds,5-aminoisophthalic acid as the skeleton, pyridine. as the coordination group to obtain six chiral pyridine ligands. Four charil one-dimensional chain coordination polymers and two nietal-organic cages were achieved via self-assembly. The structures of the compounds were determined with MS, NMR, EA, IR and XRD. The thermal stability was studied by TG. The fluorescence properties of the complexes were also studied. Moreover, unique chiral hydrogen-bonding supermolecular synthons among (1S)-(-)-camphanic amide moieties were discovered from crystal structures.Recently, iridium(Ⅲ) complexes have achieved considerable attention due to high emission efficiency, good stability and easy tuning of emission colors by modified ligands. Compared with chiral ruthenium complexes, the chirality research of indium (Ⅲ) complexes were limited. In the second part, we synthesized two neutral iridium(Ⅲ) complexes (Ir(ppy)2(fppy), Ir(ppy)(fppy)2) and two cationic iridium(Ⅲ) complexes ([Ir(ppy)2(qpy)](PF6), [Ir(cppy)2(qpy)](PF6)) based on (2-phenyl pyridine)(ppy),2-(4-formylphenyl)pyridine (fppy), )-(-)--camphanic-amide)phenyl)pyridine (cppy) and 4,4’:2’,2":4",4’"-quaterpyridine (qpy) ligands. Moreover, Ir(ppy)2(fppy) and [Ir(ppy)2(qpy)](PF6) were enantioseparation by use of proline. The structures of the complexes were characterized by MS, NMR and EA. Their photophysical properties were studied by UV-visible absorption spectra, fluorescence emission spectra and the fluorescence lifetime. Electrochemical properties of complexes were studied by cyclic voltammetry. Interestingly, all these iridium(Ⅲ) complexes as chiral functional reagents could be modified spectroscopic properties with covalent bond, and be assembled to chiral functional coordination complexes or coordination polymers.