Synthesis And Structures Of A Few Transition Metals Coordination Polymers Constructed By Supramolecular Self-assembly

Recently, coordination polymers and supramolecular architectures formed through the deliberate selection of metals and multifunctional ligands have received much attention for their fascinating structural diversity and specific functionality, which have made them highly promising in various applications, particularly absorption, catalysis and molecular magnetization. The aim of this work is to investigate the self-assembly laws and structures of coordination polymers constructed by either covalent bonds or weak intermolecular forces. This thesis is divided into five chapters.In the first chapter, one briefly introduce about the concept and development of coordination polymers are given, as well as the current survey, research significance and the results in this thesis.In the second chapter, one three-dimensional polymeric cobalt(II) complex constructed with p-phthalic acid in the presence of an additional chelate ligand 4-aminopyridine has been described. This observation combining the reported results suggests that: 1) Due to the weak acidity and less solubility of dicarboxylates acid and their complexes, the conditions to synthesize its coordination polymers are relatively critical; 2) The coordination polymers synthesized under hydrothermal conditions are easily packed more stable than those synthesized under common temperatures and pressuresIn the third chapter, construction and structures of two coordination polymers having diverse dimensional and shapes, self-assembled by 2-pyrazinecarboxylatic acid(2-pzcH) with metal salts have been described. The results shows that: 1) Only polymeric complexes with fixed component can be constructed varying the ratios of metal ions and 2-pzcH ligand. It indicates that the formation of the coordination polymers takes on specificity. 2) The transition metal ions show important control ability on the structures of coordination polymers.In the fourth chapter, construction and structures of coordination complexes containing spacer 4,4'-methylenedianiline(4,4'-cda) are described. Six coordinationcomplexes having diverse dimensional and shapes are self-assembled by 4,4'-cda with metal thiocyanate or metal azide under different conditions. The results shows that: 1) Under weakly acid condition, the ligand 4,4'-methylenedianiline has ability to form double-stranded chains with bivalent metal ions which have octahedral geometry. And it is more suitable for rigid acids, for example Ni(II) in complex 4 and Co(II) in complex 6. 2) When the additional chelate ligand SCN- is insteaded by N3-, it is found that the double-chains in structures in extended into double-rings by bridging azid groups with the μ-1,3 mode. It indicates that N3~ has better bridging ability than SCN- in single-metal coodination polymers of solid state.In the fifth chapter, a concise conclusion about this work and an outlook are presented.