The Synthesis And Charaterization Of A Series Rare Earth Complexes

We have synthesized six novel rare earth complexes with 2-D and 3-D structures under hydrothermal and solution conditions. And we characterizations of complexes 1-6 by single crystal X-ray diffraction, IR, elemental analysis, thermal analysis and luminescence have also been described. The main achievements and creativity are given below:1. We set glyphosate (H3L) as the first ligand and oxalate as the second ligand to react with Eu(Ⅲ), Tb(Ⅲ) and finally two novel complexes, [Eu2(H2L)2(C2O4)2]·2.51H2O (1), [Tb2(H2L)2(C2O4)2]·2.46H2O (2) (H2L =glyphosate) have been synthesized under hydrothermal conditions. The H2L- ligand connect Ln3+ions through its O atoms from phosphate group and carbonyl group and formed 1-D Ln-H2L- double chains. The neighboring four 1-D chains are connected with each other through O1 atoms from phosphate group and forming 3-D structures which contend 1-D channels in c direction. Oxalates as the second ligand chelated Ln3+ ions in the aforementioned 1-D channel and forming a 1-D Ln-C2O42-zigzag chain along c direction. Compounds 1 and 2 exhibit typically strong red and green fluorescent emission at room temperature, respectively, indicating the effective energy transfer from the ligands to the lanthanide(Ⅲ) center. As Ln-C2O42- chains set in the channels so compound 1 have small surface area and weed gas adsorption ability.2. Glyphosate was selected as ligand to react with Eu(NO3)3·6H2O and Tb(NO3) 3·6H2O respectively under hydrothermal condition and two colorless acicular single crystal Eu(NO3)(C6H10N2P2O8)(3) and Tb(NO3)(C6H10N2P2O8) (4) were harvested. Glyphosate have dehydration condensation under hydrothermal conditions and formed a new ligand: N,N'-diphosphate 2,5-dicarbonyl piperazine which is six coordinated though the phosphate group. The O atoms from phosphate group connected Ln3+ and formed 1-D double-chain. The chains were connected by the O atoms from piperazine ring to a 2-D plan. The plans are further connected by N,N'-diphosphate 2,5-dicarbonyl piperazine which set between layers and forming a 3-D structure. Fluorescence spectroscopy shows that complexes 3 and 4 exhibit typically strong red and green fluorescent emission at room temperature, respectively.3. N-oxide nicotinic acid (HNNO) has been selected as the first ligand and malonate as the second ligand to react with Eu(Ⅲ) though solution method and harvest a single crystal [Eu(NNO)(OOC-CH2-COO)(H2O)3]·2H2O (5). X-ray shows that every malonate connected two Ln3+ cations and formed 1-D chain which were further connected by a pair of O atoms from carbonyl group from NNO ligands and formed 2-D layers. During the neighboring layers there are strongπ-πfunction which made the structure more complicated. Complexes 5 exhibit typically strong red fluorescent emission at room temperature.4. AlMo6(OH)6O183- polyoxometalates anion has been selected as building units, Hydroxide-3-Carboxy-1-carboxymethyl pyridine as ligand and Eu(Ⅲ) as the center ions to built a new structure based on Anderson type polyoxometalates anion complexes:[Na(C8H7NO4)(C2H3O3)Eu(AlMo6H6O24)(H2O)3]2·17.98H2O (6). The X-ray diffraction data show that acetate is tridentate ligand which connected a pair of Eu3+ and a Na+ ions while 3-Carboxy-1-carboxymethyl pyridine acted as dual-linked ligande connected a pair of Eu3+. The Na+ions connected with Eu3+ by sharing O atoms from water and acetic forming a Na-Eu-Eu-Na short inorganic chain which connected with [AlMo6H6O24]3- alternately and formed the 1-D chains. The 2-D layer are formed by the connection of Eu3+ and [AlMo6H6O24]3- from 1-D chain. The [AlMo6H6O24]3- which set between the layers connected neighboring layers to form the 3-D framework. Compound 6 have big channels along a, b, c directions and exhibit typically strong red fluorescent emission at room temperature.