Dicarboxylic Acid Complexes Of The New Rare Earth And Rare Earth Benzoic Acid Derivative Complexes

Seventeen single crystals of rare earth carboxylate complexes were obtained in all by diffusion method, hydrothermal method or solvent method, which have not been reported by literatures. The structures and properties were characterized through X-ray single-crystal diffraction, elemental analysis, IR spectrometry, UV spectrometry, fluorescence spectrometry and DTA-TGA. The following is the main results:1. Benzene-1,4-dioxyacetatic acid as the ligand, four new rare earth complexes, {Ln2(1,4-BDOA)3(H2O)4·6H2O}n (1,4-H2BDOA = benzene-1,4-dioxyacetatic acid; Ln = Dy, 1, Ho, 2, Tb, 3 and Sm, 4) were prepared by diffusion reaction. The four complexes are isomorphous with similar crystal structures. In the complexes, each Ln3+ ion is nine-coordinated with seven oxygen atoms from 1,4-BDOA ligands and two oxygen atoms from water molecules. The adjacent two Ln3+ ions are bridged by carboxylate groups from 1,4-BDOA ligands in bidentate-bridging and chelating-bridging modes as a building block. These building blocks are cross-linked through 1,4-BDOA spacers to form 2-D network structure. The adjacent 2-D layers are further interlinked by hydrogen bonds to form a 3-D supermolecular structure. The fluorescent spectra of complex 1, 3 and 4 show the characteristic emission of Dy3+, Tb3+ and Sm3+ ion, respectively.2. Benzene-1,2-dioxyacetatic acid and 1,10-phenanthroline as the ligand, three rare earth binuclear complexes [Ln2(1,2-BDOA)3(phen)2(H2O)2]·2H2O (Ln = Eu, 1, Tb, 2 and Dy, 3; 1,2-H2BDOA = benzene-1,2-dioxyacetatic acid; phen = 1,10-phenanthroline) were firstly synthesized by hydrothermal method. In the binuclear molecule, the two center Ln3+ ions are linked by only one 1,2-BDOA ligand through its two bidentate-chelating carboxylate groups. And the other two 1,2-BDOA ligands act as a terminal ligand using two monodentate carboxylate oxygen and ether oxygen atoms to chelate the same Ln3+ ion, respectively. 3-D supramolecular frameworks are built up by the hydrogen bonds andπ-πstacking interactions. The fluorescent spectra of the three complexes show the characteristic emission of Eu3+, Tb3+ and Dy3+ ion, respectively.3. 4-Sulfobenzoic acid and 1,10-phenanthroline as the ligand, four complexes {[Dy2(4-SBA)3(phen)2(H2O)4]·2H2O}n (1), {[Eu2(4-SBA)3(phen)2(H2O)2]}n (2), {[Tb2(4-SBA)3(phen)2(H2O)4]·2H2O}n (3) and {[Sm2(4-SBA)3(phen)2(H2O)2]}n (4) (4-H2SBA = 4-sulfobenzoic aicd) were firstly synthesized by hydrothermal method. The four complexes show two different structures. Complex 1 and 3 are similar and have 1-D chain structures by bidentate and tridentate 4-SBA ligands as linkages and 3-D network structures were formed by strong hydrogen bonds. The complex 2 and 4 are similar and have 2-D network structure by tridentate and tetradentate 4-SBA ligands as linkages. The fluorescent spectra of the four complexes show the characteristic emission of Dy3+, Eu3+, Tb3+ and Sm3+ ion, respectively.4. The derivations of benzoic acid as the ligand (2-iodobenzoic acid, 3-iodobenzoic acid, 3-bromobenzoic acid and 2-trifluorobenzoic acid), six mixed rare earth complexes were synthesized by solvent method and characterized.