Research On Supramolecular Complexes With Flexible Open-chain Schiff Base Ligands

This work proposed new ideas in the self-assembly of supermolecules, as well as controlled design strategies of functional coordination compounds through investigations of the crystal structures and properties of supramolecular complexes with series of flexible open-chain Schiff base ligands. The thesis is included six parts.1. The background of this work is concisely introduced with the emphasis on the current survey of assembly and regulation of helical structures, secondary building of supramolecules, supramolecular devices based on allosteric effects, metalloenzyme mimics related to absorption and transport of gas in bio-supramolecular field and the aim as well as the progress of this work have been outlined. Flexible open-chain Schiff bases were selected as the main ligands, which is based on the follow two points. Firstly, these ligands are easily prepared and modified; the second is that the structures of flexible open-chain Schiff bases' complexes is susceptible and changefully.2. The successful design and synthesis of series of double helical complexes with flexible open-chain Schiff base ligands are described, in which regulation between single and double helical structures, symmetric and asymmetric helical structures, low degree and high degree of asymmetry of helical structures have been accomplished. Antitumour activity of three double helical Mn(III) complexes was investigated.3. Two kinds of advanced supramolecular assembly with the flexible open-chain Schiff base complexes as the Secondary Building Blocks (SBUs) have been synthesized and structurally characterized: the first is based on the coordinating binding with double helical complexes as the SBUs to construct one-dimensional networks; the second is based on the hydrogen bond binding with mononuclear Mn0II) complexes.4. the successful design of synthesis of Ce(III) and Ce(IV) complexes with flexible open-chain Schiff base ligands are described, in which the valence state of metal centers and structure mode of the complexes were regulated and controlled by the basicity of the reaction solution. Thus, the absorption and release of oxygen could also be controlled by the basicity.5. The study of lanthanide complexes of the flexible open-chain Schiff base ligands is introduced with emphasis on the absorption and fixation of aerial CO₂. The fixation modes are regulated by the flexibility of the spacers. The fixation action could be controlled by the radii of the alkaline used in the reaction.At last, a briefly conclusion and an outlook on this work have been noted.