Synthesis, Structure And Nonlinear Optical Properties Of Metal Phosphor Coordination Complexes

The first second harmonic generation(SHG) phenomenon was discovered in 1961 use quartz with Cr:Al₂O₃ by Franken.It not only symbolized the naissance of the nonlinear optic science,also accelerated the development of the nonlinear optical crystal forcefully.Along with the deep research in the nonlinear optic science and the continuous development of the new materials,nonlinear optical crystal materials have the important potential applications in telecommunications,optical computing,laser diode,optical signal processing,and optic data storage.These research and applications bring forward more requests for the physical and chemical properties of nonlinear optical crystals.At the same time,many applications are developing endlessly.Therefore,search and synthesize new type of nonlinear optical crystal with excellent properties is a very important task.Also,it becomes a focus for many scientists in this field.The research on the nonlinear optics includes two aspects.One is discover new nonlinear optic phenomena,find out their mechanism and rule and develop new nonlinear optic technique and materials.The other is to apply nonlinear optic technique into the relative fields.Metal-organic complex is new type of semi-organic nonlinear optical materials that were discovered in the latest two decades.Metal-organic complex can combine the advantages of both organic and inorganic materials,such as high NLO efficiency,low cut-off wavelength,various and flexible of structure,and stable physical and chemical properties.In metal-organic complex,the central mental ions can act as electron acceptor,donor,or the bridge connects the donor and acceptor.The physical and chemical properties of the complex can be effectively dominated by changing the central ions and ligand.Consequently,metal-organic complex is a very promising nonlinear optical crystal.In this dissertation,we chose some simple ligands as raw materials.A series of metal-organic complex were synthesized under room temperature.Their molecule structures were determined and some relative physical and chemical properties were studied in the purpose of discovering some new phenomena between the structure and NLO properties.It will settle foundation studies for developing this work frothily.The main works in this dissertation are list as follows:(1) TPPO was introduced into the synthesis of the second order nonlinear optic crystal materials.A series of complex containâ…¡B group metal and TPPO were synthesized.Their formula were determined as ZnCl₂(TPPO)₂(1),ZnBr₂(TPPO)₂(2), ZnI₂(TPPO)₂(3),CdCl₂(TPPO)₂(4) and HgBr₂(TPPO)₂(5).The frequency-doubling effects and transmittance spectrum were measured.The results indicate that the frequency-doubling effect of crystal(1) is most intensity in all of these five crystals. The powder SHG intensity of(1) was estimated about 4 times that of KDP.The powder SHG intensity of(2),(3) and(5) were decreased in turn.Big crystal of(1) was grown under room temperature.The conversion efficiency and threshold were measured to be 1.5%and～2.4 GW/cm².Some properties of(1) are superior to that of KDP.More importantly,the crystal of(1)can reach phase matching of SHG in the visible region.Therefore,it appears to be a promising candidate for fabricating NLO frequency conversion devices.(2) In this chapter,NCS^- was introduced into the system of TPPO andâ…¡B group complex.Zn(NCS)₂(TPPO)₂(6),[Cd(NCS)₂(TPPO)]_n(7) and [Zn(TPPO)₄][Zn(NCS)₃(TPPO)]₂(8) were synthesized under room temperature and their structure were determined.Only(8) has a noncentrosymmetry configuration. Powder SHG intensity of(8) was estimated about 0.5 time that of KDP.(3) p-Aminobenzoic acid pillared coordinated polymer[Zn(PABA)₂]·H₂O(9), [Zn(H₂O)₂(H₂PO₄)₂]·2PABA(10) and PABA·H₃PO₄(11) were synthsizied under room temperature,and their structure were determined.Only(9) has a noncentrosymmetry configuration.The powder SHG efficiency of(9) is comparable with that of KDP. Furthermore,the SHG efficiency of compound(9) after removal and reintroduction of the guest H₂O molecules were measured.The SHG efficiency is decreased obviously after removal of the guest H₂O molecules.And it can come back when the H₂O molecules were reintroduced into the framework.This can be attributed to the two following reasons.(a) When the H₂O molecules were removed,the relative positions of some atoms in the crystal lattice may be changed to a certain extent.(b) The hydrogen bonding between H₂O molecules and carboxylic oxygen atoms may have more contribution to the SHG efficiency.So,the SHG efficiency decreased with the removal of the H₂O molecules.(10) and(11) are 3D supramolecular hybrid complex pillared by PABA ligand.The structure of(10) was featured by containing ZnO₆ octahedral,and(11) was a hybrid complex constructed from alternately arranged organic acid and inorganic acid layers.(4) In this chapter,a series of zero dimensional complex Ln(phen)(TPPO)₂(NO₃)₃ (Ln=La,Ce,Pr,Nd) were synthesized under room temperature.We tried to synthesize the complex using heavy rare earth ions after Nd,but failed.We think it was controlled by lanthanide contraction effect.