Synthesis, Structure And Fluorescence Performance Of Coordination Polymers From In Situ Ligands Reaction

Recently, the design and assembly of coordination polymers have been of great interests due to their interesting topologies and potential applications as catalyst, superconductor, magnetic, and optical materials. In situ ligand synthesis is of great interest in coordination chemistry as an effective method in synthesizing coordination compounds. Actually, a variety of novel coordination complexes involving hydro(solvo)thermal in situ synthesized ligands were synthesized successfully, which could not be prepared by ordinary methods. We have synthesized nine coordination compounds and one organic compound using H4bta, H2ox and d10 transition metal as primary raw material through hydrothermal in situ acylation reaction. we try to conclude the main factors of influencing the synthesis of coordination polymers, find the regulating functions of organic ligands for structure, catch the synthesis rules.1. Two coordination polymers [Zn(μ2-H2bta)1/2 (μ4-H2bta)1/2(phen)(H2O)]n (1) and [Zn(μ4-bta)1/2(phen)(H2O)]n (2) with H4bta, ZnCl2 and phen have been synthesized through hydrothermal syntheses method by controlling pH value.Compound 1 is 2-dimensional layer structure with two kinds of H4bta of different coordination modes, while 2 is a 1-dimensional double metal chain. Both of them are linked into 3-dimensional net work structure by hydrogen bonds andπ-πinteraction. We have characterized them by elemental analysis, IR spectroscopy and studied their fluorescence.2. A series of metal-organic frameworks (MOFs) 4-8 based upon d10 metal and the ligand H4bbh (3) (H4bbh = benzene-1,2,9,10- bihydrazide) synthesized through hydrothermal in situ acylate reaction with H4bta (H4bta = benzene-1,2,4,5- tetracarboxylic acid) and hydrazine hydrate (N2H4·H2O) have been prepared and characterized. Because of the special structure, H4bbh exhibits a variety coordination modes in the networks revealing very interesting topologies architectures. Compounds [Zn(H4bbh)(phen)(H2O)]2 (4) and [Zn(μ2-H2bbh) (2,2'-bpy)]2 (5) are all dinuclear. [Zn(μ2-H2bbh)1/2(μ2-H2bbh)1/2(H2O)]n (6) exhibits 2-dimensional layer containing two different kinds coordination modes of H4bbh. [Cd(μ3-H2bbh)(phen)]n (7) is a 1-dimensional double-metal chain. The four compounds were linked by hydrogen bonds andπ-πinteractions into 3-dimensional architecture. [Pb4(μ6-H2bbh)2(μ6-H2bta)2]n (8) is a 3- dimensional structure with ligands framework disordered. We have studied the effects of the reaction conditions such as pH value, temperature and solvent and so on. All of them were characterized by IR, elemental and fluorescence analysis. They show good florescence property in solid state condition at room temperature.3. Two coordination polymers [Co(ox)(Him)(bim)]n (9), [Mn(OH)(ox)1/2 ]n (10) have been synthesized with different metal salts under the same examination conditions through hydrothermal reaction. We obtained compound 9 by hydrothermal in situ acylate reaction with oxalic acid and o-phenylenediamineligands, but no in situ reaction when we synthesized compound 10. Different metal may influence the in situ acylate reaction between oxalic acid and o-phenylenediamine ligands. Compound 9 is 1-dimensional zigzag chain structure linked byμ2- coordination mode of oxalic ligand and compound 10 is 3- dimensional network structure withμ4- coordination mode of oxalic chains intersecting the OH- layers. We characterized them with IR, elemental.