Syntheses,Fluorescent And Magnetic Properties Of Coordination Complexes Derived From Tartaric Acid Derivatives D-H₂DBTA And D-H₂DTTA

Coordination Polymers(CPs)are coordination complexes with infinite structure formed by combining inorganic metal cations or metal clusters with organic ligands through coordination bonds.A great deal of attention has been directed toward the use of CPs in the designs and syntheses of new materials.These CPs are widely regarded as attractive materials for applications in catalysis,fluorescence,gas storage,sensing and solar energy conversion and so on.In this thesis,nine novel complexes were obtained from two chiral tartaric acid derivatives,(+)-Dibenzoyl-D-tartaric acid(D-H₂DBTA)and D-(+)-Di-p-toluoyl tartaric acid(D-H₂DTTA)by solvent volatilization reaction at room temperature,five of which are coordination polymers.The structures of these complexes were characterized by X-ray single and powder crystal diffraction,infrared spectroscopy and elemental analysis.The thermal stabilities,fluorescence,and magnetic properties of complexes have also been researched.1.Using the D-H₂DBTA and the transition metal cations Zn²⁺and Cd²⁺,the complexes 1?4 were synthesized by solvent volatilization at room temperature.X-ray single-crystal diffraction analyses reveals that complexes1 and 4 all crystallize in orthorhombic P2₁2₁2₁ space group,which are characterized by mononuclear one-dimensional(1D)structures respectively.The complex 3 crystallizes in orthorhombic P2₁2₁2 space group with mononuclear zero-dimensional(0D)structure.While complex 2 crystallizes in monoclinic P2₁ space group with mononuclear 1D structure.The diverse structures show that both metal cations and auxiliary ligands can regulate the structure of the complex.The studies of fluorescence properties reveal that the four complexes all perform good luminescence in aqueous solution,so we further studied the potential application value of the complexes as fluorescent probes.The results show that the fluorescence intensity of complex 1 can be significantly quenched by Cu²⁺,while increased by Zn²⁺.The value of Cu²⁺quenching constant K_sv is 7.35×10⁴ M^-1 which is higher than that of some reported complexes,and the detection limit is 0.298?M.Such high K_sv and low detection limit imply that complex 1 is a good candidate for the detection of Cu²⁺cations.According to the results of the mechanism study,we infer that the reason for the fluorescence quenching may be the weak interaction between Cu²⁺and complex 1.Similarly,the addition of Zn²⁺can also enhance the fluorescence intensity of complex 4.This result can be attributed to the carboxyl O which is easily combining with Zn²⁺and has significant selectivity for Zn²⁺.The combination of the ligands and metal cations will enhance the rigidity of the ligands and reduce the energy loss caused by the non-radiation decay of the ligand and then enhance the fluorescence of the complex.The detection limit of complex 4 for Zn²⁺is 0.525?M,which can be used as a fluorescent probe for the specific detection of Zn²⁺in aqueous solution.In addition,complexes 2 and 3 did not show specificity for the detection of cations or anions,which may be caused by the different structures of the four complexes.2.Four novel complexes 5?8 based on D-H₂DBTA and transition metal cations were successfully synthesized and fully characterized.Complex 5crystallize in orthorhombic P2₁2₁2₁ space group featuring mononuclear 1D structure.Complexes 6 and 7 are triclinic P1 space group with mononuclear0D structures.Complex 8 is monoclinic P2₁ space group characterized mononuclear 0D structure.The different structures of the complexes once again show that the metal cations have a certain regulatory effect on the structure of the complex.Magnetic studies confirm the existence of ferromagnetic interactions between manganese cations of the one-dimensional chain in complex 5.In addition,the fluorescence properties of complexes 6,7 and 8 indicate that the different structures and the electronic configurations of the metal cations will change the luminescence properties of the complexes.3.A new chiral one-dimensional gadolinium coordination polymer[Gd(HDTTA)₃(CH₃OH)₃]_n(9)(D-H₂DTTA=(+)-Di-p-toluoyl-D-tartaric acid)was synthesized at room temperature,and fully structurally characterized by infrared,elemental analysis,X-ray single-crystal and powder diffraction.The structure analysis shows that complex 9 belongs to the trigonal system with R3 space group and displays an infinite chain structure along the c axis.In 9,neighboring Gd³⁺cations are connected by three partly deprotonated HDTTA^-ligands with the Gd···Gd distance of 7.686(1)?.Thermal analysis results show that complex 9 has good stability below 200?.The single crystal structure and circular dichroism(CD)spectrum demonstrates the chirality of the complex.Magnetic studies reveal that complex 9 displays weak antiferromagnetic interactions between Gd³⁺cations and it exhibits a certain magnetocaloric effect(-?S_m=7.26 J kg^-1 K^-1 with?H=7 T and T=2.5 K).Complex 9 can be used as a chiral and magnetic bifunctional material.