Molecular Design And Third-order Nonlinear Optical Properties Of Nitrogen-containing Heterocyclic And Carboxylic Acid Coordination Polymers

Nonlinear optical materials have potential applications in military,optical communication and medical fields.At present,there are relatively few studies on the third-order nonlinear optics of coordination polymers constructed by nitrogen heterocyclic ligands and aromatic carboxylic acid ligands.The research on the mechanism and influencing factors of the third-order nonlinear optics of materials,as well as the relationship between the structure of the compound and the third-order nonlinear optics activity,is still limited.Therefore,we designed and synthesized a series of coordination polymers,and studied the third-order nonlinear optical activity of these coordination polymers,which provided experimental and theoretical basis for the development of new nonlinear optical materials.In this thesis,20 coordination polymers with different structures were synthesized by hydrothermal method,and were characterized by single crystal X-ray diffraction,thermogravimetric analysis,X-ray powder diffraction,UV-Vis absorption spectroscopy,Z-scan technology,etc.The structure,thermal stability and third-order nonlinear optical activity of these coordination polymers were investigated.The main research contents are as follows:1.Using 1,2-bis(4-pyridyl)-ethylene(DPE)or 3,5-bis(4,4'-pyridine)-pyrazole(Hdpp)and carboxylic acid ligands(3,5-bis-carboxybenzene sulfonate(H₂DBS),phthalic anhydride(PA),4,4'-dicarboxydiphenyl ether(H₂ODA),1,5-naphthalene disulfonate(1,5-NDS),1,4-naphthalenedicarboxylic acid(H₂NDC)and 1,3,5-benzenetricarboxylic acid(H₃BTA)as raw materials,and transition metal ions(Co(II),Mn(II),Cd(II),Ni(II))were assembled to obtain 9 compounds.In compound 1,Co(II)ions are connected to form a three-dimensional structure through DPE and DBS,and the three-dimensional structures penetrate each other.In compound 2,the Mn(II)ions are linked by two DBSs to form a ring,and then linked by DPE to form a one-dimensional chain.The Cd(II)ions in compound 3 are connected to a two-dimensional structure through DPE and NDS.In compound 4,Co(II)ions are connected by PA to form a one-dimensional chain,and the chains are connected by Hdpp to form a two-dimensional layer.In compounds 5 and 6,the metal ion adopts an octahedral configuration,and the metal ions are coordinated with Hdpp,BTA and ODA,respectively,to form a separate structure.The Ni(II)ions in compound 7 are connected to form a one-dimensional chain by ODA,and then connected to a two-dimensional structure by Hdpp.In compounds 8 and 9,the metal ions are connected into two-dimensional layers by NDC and Hdpp.Thermogravimetric analysis showed that these compounds have good thermal stability.Z-scan results show that compounds 1-9 have good third-order nonlinear optical activity.Compounds 1,2 and 8 have the third-order nonlinear optical positive refraction self-focusing effect.Compound 6 has the third-order nonlinear optical negative refraction self-defocusing effect,and compounds 3,4,7 and 9 exhibit third-order nonlinear optical anti-saturation absorption effect,compound 5 has a third-order nonlinear optical saturable absorption effect.2.With 1,2-diimidazolylmethylenebenzene(1,2-BIB),1,3-diimidazolylmethylenebenzene(1,3-BIB),1,4-diimidazolylmethylenebenzene(1,4-BIB)and four carboxylic acids(H₂ODA,H₂NDC,PA,4,4'-biphenyl ether dianhydride(H₄BPTC))as raw materials,we prepared 8 compounds.The Ni(II)ions in compound 10are connected by 1,3-BIB and BPTC to form a one-dimensional chain.In compounds 11 and 12,the metal ions are connected into two-dimensional layers by 1,3-BIB and PA.The Ni(II)ion in compound 13 is connected to a three-dimensional structure through 1,3-BIB and ODA.In compounds 14 and 15,five metal ions are linked to 1,3-BIB and 1,4-BIB by NDC to form a three-dimensional structure.In compounds 16and 17,the metal ions are connected into a two-dimensional layer structure through NDC and 1,4-BIB,1,2-BIB and NDC,respectively.Z-scan method results show that compounds 10,13 and 17 have a third-order nonlinear optical anti-saturation absorption effect,compounds 11 and 14 have a third-order nonlinear optical negative refraction self-defocusing effect,and compounds 12,15 and 16 have a third-order nonlinear optical self-focusing effect.3.Using 4-phenyl-2,2':6',2''-terpyridine(PTP),1,5-NDS as raw materials,we prepared 3 compounds.Compound 18 has a discrete structure.In compounds 19 and 20,the metal central ions are connected to form a one-dimensional chain structure through NDS and PTP.The results of Z-scan method show that compounds 18-20 have the third-order nonlinear optical anti-saturation absorption effect.4.The relationship between the structure of these coordination polymers and the metal ion types and the third-order nonlinear optical activity of the materials are summarized.