Synthesis,Structures And Properties Of Several Poly-Carboxylic Metal-Organic Complexes

As a joint area of inorganic chemistry, physical chemistry and materials chemistry, metal-organic frameworks (MOFs) with original structures and diversified functions have been attracting more and more attention in the past decades.Poly-carboxylic ligand is most commonly used to build metal-organic frameworks due to the strong coordination capability and diversity of its carboxylate radical.In order to investigate the influence of different factors, such as the structure of ligands, the metal ions and auxiliary agent, on the structure of coordination compounds, kinds of poly-carboxylic ligands or derivates have been synthesized from 5 -aminoisophthalate,5-hydroxyisophthalate, 3-aminobenzoic acid and 2-(4-hydroxyphenyl)acetic acid as raw materials. And the corresponding metal-organic frameworks were also obtained. The products were characterized by FT-IR analysis, powder X-ray diffraction, single-crystal X-ray diffraction and 1H-NMR analysis. In addition, the structures and properties of the obtained complexes were also discussed.[Zn (L1) ]n(1) was synthesized by the reaction of pentylcarboxyl amine dimethyl isophthalate and Zn2+; {[Cd(L2)(H2O)]·2H2O}n(2) and{[Co(L2)2·(H2O)2]·2H2O}n(3) were obtained through the coordination of trifluoroacetamide dimethyl isophthalate with Cd2+ and Co2+ respectively.The structures of 1-3 and the coordination modes of ligands were studied in this part.From 5- (2-hydroxyethoxy) isophthalate dimethyl ester ((Me)2L3) as ligand and 4,4-bipyridine as auxiliary agent, two coordination polymers{[Cd2(L3)2(bpy)(H2O)4]·4H2O}n(4) and [Cu2(L3)2(bpy)(H2O)4]n(5),which could be converted to each other when surrounded by corresponding metal ions, were synthesized; Meanwhile, {SmL3(HL3)(H2O)2}n(6), {EuL3(HL3)(H2O)2}n(7) and {TbL3(HL3)(H2O)2}n(8)were also obtained by the reaction of 5- (2-hydroxyethoxy) isophthalate with Sm, Eu and Tb respectively. In this part, the thermal stability and fluorescent property of complex 6-8 were investigated.Two isomorphous complexes {[Co(L4)2(H2O)4]·2H2O}(9) and {[Mn(L4)2(H2O)4]·2H2O}( 10) were synthesized through the coordination of(E)-3-((5-(carboxymethyl)-2-hydroxyphenyl)diazenyl) benzoic acid with Co and Mn; the single chiral helical [Zn(L5) (H2O)2]n(11) was got by the reaction of (E)-3-((2-(allyloxy)-5-(carboxymethyl)phenyl) diazenyl)benzoic acid and Zn. The structure and ultraviolet absorption property of complex 11 were researched.The investigation on the structures of complexes contributes to the prediction of their performance. And the study of properties will largely broaden the application prospect of MOFs.