微生物代谢工程研究组知识库

A series of three-dimensional rare-earth coordination polymers, [M-2(bpdc)(3)(H2O)(4)] (M = Y [1], Sm [2], Eu [3], Gd [4], Tb [5], Dy [6], Er [7], and Yb [8]) were synthesized by solvothermal reactions of 2,2-bipyridine-5,5-dicarboxylate (bpdc) with corresponding metal salts. Single-crystal and powder X-ray diffraction analyses demonstrated that these coordination polymers are isostructural. The carboxyl groups of the bpdc ligand are coordinated to metal ions and the 2,2-bipyridine moieties are left free due to the preferable affinity of rare-earth metals for oxygen-donor atoms. The adjacent eight-coordinate MO8 cores show dicapped trigonal prismatic environments; they are interconnected by carboxyl groups and are further bridged through the bipyridyl linkers to give quite dense three-dimensional networks. Photoluminescent studies at room temperature reveal intense red and green luminescent emissions for Eu-III and Tb-III analogues, respectively. Furthermore, it is noteworthy that bpdc shows an effective antenna effect in sensitizing emissions from Eu-III and Tb-III ions. Thermogravimetric analyses demonstrate that these coordination polymers exhibit exceptional thermal stability (decomposing at T > 580 degrees C under N-2 for compound 1). Water-resistance measurements of these coordination polymers show excellent hydrothermal stability.