Synthesis, Structures And Properties Of Complexes Based On 5-chlorosalicylic Acid And Dicarboxylic Acid

Aromatic carboxylic acid ligands have been commonly used to construct metal-organic complexes because they have diverse coordination and better coordination ability, and they can form the metal-frameworks with special properties like optical, electrical, magnetic, gas storage and absorption, etc. In order to get novel complexes, much effort should be devoted not only to selecting organic ligands, but also to investigating the related factors that have important effect on the structures of complexes like temperature, PH value, solvent, metal ions, material ratio and template agent. From the above consideration, ten new metal-organic complexes have been synthesized under the solvothermal based on monocarboxylic acid 5-Chlorosalicylic acid, dicarboxylic acid terephthalic acid and dipicolinic acid 5-(Pyridin-3-yl)isophthalic acid and 5-(Pyridin-4-yl)isophthalic acid. And they have been structurally characterized by IR, elemental analyses, TGA and single crystal X-ray diffraction, and some of which were photophysically investigated.Firstly, two metal-organic complexes derived from 5-Chlorosalicylic acid(H2L) were synthesized in the presence of auxiliary organic molecule with reactive functional groups(1,10-phenanthroline, 1,3-Di(4-pyridyl)propane) by hydrothermal conditions, {[Pb(HL5)2(phen)(H2O)]·H2O}n(1), [Zn2(HL5)4(bpp)2]n(2). the carboxylate group of the coordinated HL5- adopt ?1-?1: ?0 coordination fashion to connect one Pb(II) ion but all the carboxylate groups adopt the different ?1-?1: ?1 mode in the crystal of compoud 2 compared to 1, which can show that monocarboxylic have various coordination modes. The solid-state photoluminescent properties at room temperature and thermal decomposition process of complexes were investigated.Secondly complex [Pb(PBDC)]n(3) was synthesized by the only ligand terephthalic acid. To the best of our knowledge, terephthalic polymers combined bridging tetradentate? 4-?2: ?2 and chelating-bridging tridentate? 2-?2: ?1 coordination modes have never been reported.Finally, we adopted isomers 5-(Pyridin-3-yl)isophthalic Acid and 5-(Pyridin-4-yl)isophthalic Acid as target ligands and obtained 7 new complexes through hydrothermal synthesis : [Fe(3-pyip)(H2O)2]n(4), [Co(3-pyip)(H2O)2]n(5), [Ni(3-pyip)(H2O)2]n(6), [Mn(3-pyip)(H2O)2]n(7), [Zn(3-pyip)(H2O)2]n(8), [Pb(3-pyip)]n(9) and [Cd(4-pyip)(Me OH)(H2O)]n(10). Single-crystal X-ray diffraction analysis reveals that compounds 4-8 are isostructural heterogeneous withcrystal and showed identical 3-D supramolecular architecture that adopt different metal center. The carboxylate groups of the pyip2- ligands adopt two different coordination modes( ? 1-?1: ?1 and ? 1-?1: ?0)and link metal atoms to form interesting infinitely extended helical feature along their direction. Complex 9 showed that different coordination mode with complexes 4-8(two carboxyl adopt? 1-?1: ?1?? 3-?2: ?2 separatedly), and their structure also are different, which reveal that the same carboxylic acid ligand can form various structural complexes because of the difference of coordination modes. In addition, fluorescent properties of complexes 4-9 were investigated.