Zusammenfassung
Nine novel lanthanide coordination complexes with formulae {[Ln(TTTA)(H(2)O)(2)]center dot 2H(2)O}(n) (Ln = Ce, 1 center dot Ce; Pr, 2 center dot Pr, Nd, 3 center dot Nd; Sm, 4 center dot Sm; Eu, 5 center dot Eu and Tb, 6 center dot Tb) and {[Ln(TTTA)(H(2)O)3]center dot 3H(2)O}(n) (Ln = Dy, 7 center dot Dy; Er, 8 center dot Er and Yb, 9 center dot Yb) have been synthesized by hydrothermal ...
Zusammenfassung
Nine novel lanthanide coordination complexes with formulae {[Ln(TTTA)(H(2)O)(2)]center dot 2H(2)O}(n) (Ln = Ce, 1 center dot Ce; Pr, 2 center dot Pr, Nd, 3 center dot Nd; Sm, 4 center dot Sm; Eu, 5 center dot Eu and Tb, 6 center dot Tb) and {[Ln(TTTA)(H(2)O)3]center dot 3H(2)O}(n) (Ln = Dy, 7 center dot Dy; Er, 8 center dot Er and Yb, 9 center dot Yb) have been synthesized by hydrothermal reactions of a new flexible ligand TTTA (2,29,2"-[1,3,5-triazine-2,4,6-triyltris(thio)] tris-acetic acid) with corresponding lanthanide nitrate and characterized by single-crystal X-ray diffraction, IR, thermal analysis, luminescence and magnetic measurements. Due to the synergistic effect of lanthanide contraction with diverse coordination modes and conformations of the flexible ligand, they have three structural types from 3-D polymers to 0-D dimers. Type I for large ions, 1 center dot Ce, 2 center dot Pr and 3 center dot Nd, possesses a rare 3-D five-connected 4 6 6 4 network with 1-D helical inorganic Ln(2)O(2) chains bridged by the organic ligands; type II for medium ions, 4 center dot Sm, 5 center dot Eu and 6 center dot Tb, exhibits 1-D chains constructed from Ln(2)( CO(2)) 4 units connected by the V-shaped conformational ligand; and type III for small ions, 7 center dot Dy, 8 center dot Er and 9 center dot Yb, is scarcely an M(2)L(2) dimer structure. Fascinatingly, in the low-dimensional type II and III structures, different kinds of unusual cyclic hydrogen bonding interactions are formed which, together with other weak interactions such as S. H -O hydrogen bonds, noncovalent S. S interactions or p. p stacking interactions, play important roles in stabilizing the whole network. In addition, the 5 center dot Eu and 6 center dot Tb complexes show strong red and green photoluminescence at room temperature, respectively, and may be good candidates for potential luminescence materials. The magnetic properties for some of the structures have also been investigated.
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