Synthesis, Crystal Structure And Optical Property Of The Rare Earth With Salicylic Acid And Its Derivatives Complexes

Rare earth element has a unique electronic structure. To a great extent, throughinteracting with organic carboxylic acid, which can change and enhance itsluminescent characteristics. So the rare earth complexes show much excellent light,electricity, magnetic, and other functions. it is a new type of rare earth organicluminescent material. The research of synthesis, crystal structure and optical propertyof the rare earth with salicylic acid and its derivatives complexes has importantsignificance for obtaining the optimum of synthesis and development the newapplication value of the rare earth aromatic carboxylates. In this paper, the study iscarried out according to the rare earth ions(Re=La3+, Sm3+,Ce3+) chosen to be thecentral ions and salicylic acid,5-bromosalicylic acid and5-sulfosalicylic acid to bemain ligands,1,10-phenanthroline as the secondary ligand. We successfullysynthesized the complexes La2(C7H4BrO3)2Cl4(Phen)2, La(Hsal)3(Phen)2and thecomplexes of rare earth Ce, Sm as the center ion and5-sulfosalicylate as the ligand.The composition, crystal structures and properties of the obtained products weredetermined by Elemental Analysis (EA), Fourier Transform Infrared Spectrum (FTIR),Thermal Analysis (DSC-TGA), X-ray Single Crystal Diffractometer(XRD), UltraioletSpectrophotometer (UV) and Fluorescence Spectrophotometer (FS) et al,respectively. There is the main content as following:(1) The complexes La2(C7H4BrO3)2Cl4(Phen)2was successfully synthesized byhydrothermal method, and had been characterized by X-ray Single Crystal Diffraction,IR spectrum, Element Analysis, TG and Photoluminescent. The results showed thatthe crystal structure belongs to orthorhombic, space group Pbca with a=8.1957(10)nm，b=22.104(3) nm，c=22.110(3) nm，=90.00°, β=90.00°, γ=90.00°, Z=4, V=4054.1(8) nm3(CCDC No.:856640). The lanthanum(Ⅲ) ion is eight-coordinated bytwo nitrogen atoms, two oxygen atoms and four chloride atoms formed adodecahedron geometric configuration. The1D infinite chains framework isconsisted by a bridge of5-bromination salicylate and two chloride bridge bridging.The optical properties of the compound is studied by using FS, the results show that compound and ligands fluorescence spectrum are similar, and the fluorescencespectrum is the performance of the ligand. this shows ligands involved in thecoordination, and the fluorescence intensity of complexes is high than the ligand.(2) The mononuclear complexes of Sm(SSA)(H2O)2·H2O was successfullysynthesized by hydrothermal method, and had been characterized by X-ray SingleCrystal Diffraction, IR Spectrum, Element Analysis, TG and Photoluminescent. Theresults showed that the crystal structure belongs to monoclinic system, space groupP2(1)/n with a=8.8844(16) nm, b=8.9254(16) nm, c=14.366(3) nm,=90.00°, β=100.810(2)°, γ=90.00°, Z=4, V=1119.0(3) nm3(CCDC No.:875346). Thesamarium(Ⅲ) ion is eight-coordinated by eight oxygen atoms formed a four partyreverse prismoid geometric configuration. The optical properties of the compound isstudied by using UV and FS, the results show that compound and ligands fluorescencespectrum are similar, and the fluorescence spectrum is the performance of the ligand.this shows ligands involved in the coordination, and the fluorescence intensity ofcomplexes is lower than the ligand.(3) The mononuclear complexes of lanthanum was successfully synthesized byhydrothermal method, and had been characterized by X-ray Single Crystal Diffraction,IR Spectrum, Element Analysis, TG and Photoluminescent. The results showed thatthe crystal structure belongs to monoclinic system, space group P2(1)/c with a=16.1490(11) nm, b=10.9504(8) nm, c=22.4218(16) nm,=90.00°, β=90.0370°, γ=90.00°, Z=4, V=3965.0(5) nm3. The lanthanum (Ⅲ) ion is ten-coordinated by fournitrogen atoms from two phenanthroline and six oxygen atoms from three salicylicacid formed a double-cap four party reverse prismoid geometric configuration.(4) The three dimension complexes of cerium was successfully synthesized byhydrothermal method, and had been characterized by X-ray Single Crystal Diffraction,IR Spectrum, Element Analysis, TG and Photoluminescent. The results showed thatthe crystal structure belongs to orthorhombic system, space group Pnma with a=9.537(3) nm, b=7.026(2) nm, c=14.230(5) nm,=90.00°, β=90.00°, γ=90.00°, Z=4,V=953.5(5) nm3(CCDC No.:876487). the O5participating in coordination isdisorder, and the share of every O5position is50%. Ultraviolet performance ofcomplexes was studied by using UV, the results showed that the maximum absorptionpeak position, intensity and shape of compound is similar to the ligand, and theposition of the peak shifted to blue.