Synthesis, Structure And Catalytic Property Of Chiral Co(II) Coordination Networks Based On Amino Acid Derivatives

In the last decades, incredible large amount of architectures and flexible framework of coordination polymers have been constructed with coordination bonds, and some molecular interactions or host-guest interactions as well. Among them the chiral coordination polymers have been attracted much attention due to their interesting aesthetic topologies and their potential applications in enantioselective separation, asymmetric catalysis, luminescence materials, ferroelectric materials, nonlinear optical activities, and magnetic materials, etc.. It is demonstrated that the design and synthesis of chiral ligands is of great importance for the chemists to constuct chiral coordination polymers with expected structure and function and establish the relationship of their structure and properties.In this thesis, two chiral amino derivatives of L-Tyr (L1, C₁₅H₁₆N₂O₃), (L2, C₁₇H₁₇NO₅) have been synthesized and characterized by H-NMR. Then using these two ligands as starting material, two coordination compounds {[Co(L1)₂(H₂O)]}n (1), {[Co(L2)(H₂O)₄]·5 H₂O}n (2) have been synthesized and characterized by X-ray diffraction analysis. The results reveal that compounds 1 and 2 both crystallize in the centrosymmetric orthorhombic crystal system and the two are in the space group of P212121. In the structure of compound 1, adjacent Co centers are linked by the L1 ligands to form an infinite 1D zigzag chain along the b axis, and this zigzag chain is further connected by hydrogen-bonding interactions to form a 3D supramolecular network. Compound 2 crystallizes in the space group P212121. In solid state, a lot of lattice water molecules are contained, which construct a 1D helix chain. And the 1D helix chain of water molecules is further connected by hydrogen-bonding and weakπ-πstacking interactions to form a 3D supramolecular network containing 1D channels filled by lattice water molecules.Catalytic property of coordination compound 1 was studied. The obtained results reveal that compound 1 is a good catalyst for enantioselective oxidation of cyclohexene.