Investigation On Functional Complexes Constructed By Pyridine-carboxylate Ligands With Large Conjugated System

Complexes have potential applicants in adsorption, catalysis, molecular recognization, optics, magnetism and electrics, which have gradually developed into a novel functional materials and attracted much attention. In this dissertation, four ligands 4’-(4-carboxyphenyl)-2,2’:6’,2’’-terpyridine(Htba),4’-(3,5-dicarboxyphenyl)-2,2’:6’,2’’’-terpyridine(H2dtba),4’-(3,5-dicarboxyphenyl)-4,2’:2’,4’’-terpyridine(H2datp) and4’-(4-pyridine)4,2’:2’,4’’-terpyridine(XN) with large conjugated π electronic systems were designed and synthesized. Seven 3d complexes, fourteen 4f complexes and five3d-4f complexes have been prepared and characterized using single crystal X-ray diffraction, PXRD, TG and so on. The properties of fluorescent recognition, slow magnetic relaxation and photocatalytic hydrogen production are thoroughly studied.The main works of this dissertation are as following:(1) Three ligands(H2dtba, H2 datp and XN) were synthesized, and seven novel complexes were got by tuning the synthesis conditions. We also studied the effect of synthesis conditions on the structures. Moreover, fourteen different 4f-based complexes with different dimensionality and five 3D 3d-4f complexes were designed and prepared. Amongst them, three compounds are 1D chains based on polynuclear Dy-clusters, [Ln(datp)(OAc)(DMA)]n display 2D and 3D structure due to lanthanide contraction effect. Four complexes with different fluorescence colors were successfully synthesized by doping with different ratios of Eu3+ and Tb3+, and the characteristic sharp emission bands of Eu3+and Tb3+ions simultaneously exist in them. [LnZn(tba)(CO3)2(H2O)]n are a series of two-fold interpenetrating 3D 3d-4f complexes, and they are the first example of d-f heterometallic complexes with both chiral and interpenetrated features.(2) {[CuΙ2CuΙΙ(datp)2]·1.5DMF}n(7) is a mixed-valence Cu-based complexe,analytical test reveal that it shows semiconductor behaviour with energy band gap of2.01 eV, and it also exhibits excellent solvent stability. Pt was successfully introduced on 7, and it exhibit good photocatalytic hydrogen production performance under UV-visible-light irradiation.(3) The fluorescent recognition properties of {[Zn(datp)]·2H2O}n(5),[Ln(datp)(OAc)(DMA)]n(Ln = Eu(12),Tb(14)), [EuxTb1-x(datp)(OAc)(DMA)]n(x =0.8(12a),0.6(12b),0.4(12c),0.2(12d) and [TbZn(tba)(CO3)2(H2O)]n(19) were studied,the results indicated that 5 can detect benzaldehyde and nitrobenzene with the lowest detection limit of 10 ppm and 20 ppm. In addition, metal ions and solvent recognition of 12,12a-12 d and 14 were investigated, and 12 and 12a-12 d can detect Al3+ and acetone, while 14 displays high-sensitivity luminescent sensing to Cu2+ and pydine.19 as luminescent sensors can detect small organic molecules formol, acetaldehyde and propanal. The response time of them are all within 10 second.(4) Magnetic studies reveal that five Dy-based complexes show slow magnetic relaxation with different energy barriers.