Synthese, Structures And Properties Study Of Novel Coordination Polymers Base On Di-, Tri-, Tetracarboxylate And N-Heterocyclic Derivatives

Based on the principle of molecular engineering,9 new coordination polymers were synthesized by comprehensive utilization of N-Heterocyclic Derivatives ligands, carboxylic acid ligands and transition metal ions (or their multi-nuclear clusters) under hydrothermal conditions in this study. The influence of reaction conditions, geometric structure of coordination ligands, intermolecular force on the structure of coordination polymers were studied. Meanwhile, studing the synthetic conditions and rules for synthesing, analysizing the topological types, exploring furtherly the principle of molecular self-assembly and relationships between structures and properties for these novel compounds.The polycarboxylic acid ligands is to construct the ideal member for the design and synthesis of metal-organic coordination polymers. Polycarboxylic acid ligands can contain more than one carboxyl groups, whcih exhibit good coordination ability. The deprotonated carboxyl groups have versatile coordination modes, and hence laid the foundation for the assembly of the complex structure of the polymer. Furthermore, according to the documents about coordination polymers, transition metal elements have excellent affinity for the majority of coordination atom, such as oxygen, nitrogen and sulphur, et al., and the coordination number is changeable. Much attention is focused on the coordination Chemistry for the transition metal recently.In summary, we have chosen three polycarboxylate:H4aobtc、H3L and H2pbda ligands and the auxiliary neutral ligands:bpp、phen、2,2’-bpy after analyzing carefully. Nine unusual metal-organic coordination polymers have been successfully obtainted through hydrothermal reactions of metal ions in the presence of the selected ligands. Their structures were characterized by IR spectra, elemental analyses, ICP analyses, XRPD, single-crystal X-ray diffraction analyses; while their thermal stabilities (TG) and magnetic properties have also been studied. The successful isolation of this species provides an unprecedented example in the realm of metal-organic coordination polymer, but also laid the theoretical and experimental foundation for the study of the synthesis of the material law, directed the synthesis of related materials and the development of its nature.The molecular formulas of the compounds described in this paper are as follows: [Co(aobtc)0.5(bpp)1.5]·0.5H2O (1) [Zn(aobtc)0.5(phen)]·2H2O (2) [Zn(aobtc)0.5(2,2’-bpy)] (3) [Co(HL)(phen)] ·1.5H2O (4) [Co4(HL)3(μ3-OH)2(H2O)2]·5H2O (5) [Zn(pbda)(2,2’-bpy)] (6) [Zn(pbda)(phen)] (7) [Co(pbda)(2,2’-bpy)] (8) [Co2(pbda)2(phen)2(H2O)2]·H2O (9)Compound 1 is a 3D homochiral coordination polymers network, which constructed from dinuclear-metal cluster and organic ligands. There are polytypes of helical chains along the same direction exist in the 3D structure of 1, which is still very rare in Metal Organic Frameworks up to now. Compound 2 shows a new 3D self-digitating network, which is first assembled from the dinuclear-metal cluster. Compound 3 is a novel (2D →3D) interdigitated array, which is also constructed from dinuclear-metal cluster. Compound 4 is a new (1D→2D) interdigitating framework, constructed from metal cation and oganic ligands, which are further assembled into a 3D supramolecular structure by supramolecular interaction. Compound 5 is an unprecedented 2D Nanoscaled Quadruple-layer Metal-Organic Framework, which is constructed from octanuclear metal cluster. Octanuclear Co(Ⅱ) Clusters is linked by the H3L ligands in double- and quadruple-edged bridgings into 2D layered architecture, and each of these bidentate 2D frames is interdigitated with each other to form a 3D supramoleular framework stabilized by hydrogen bonds. Compound 6,7 and 8 are nearly isostructural and feature 1D left- and right-handed helical structure. Compound 9 is a supramolecular structure containing unusual 1D meso helices.