A Luminescent Tb(Ⅲ)-4,4’,4’’-nitrilotribenzoate Compound with a Three-dimensional Structure

A coordination polymer of [Tb(ntb)]n(1) based on 4,4’,4’’-nitrilotribenzoate ligand(ntb3–) was synthesized. Compound 1 crystallizes in monoclinic system, space group C2/c with a = 13.7318(4), b = 27.5628(9), c = 5.4046(2) ?, β = 111.142(3)°, V = 1907.88(12) ?3, Z = 4, C21H12NO6Tb, Mr = 533.24, Dc = 1.856 g/cm3, μ = 3.745 mm–1, F(000) = 1032, the final R = 0.0184 and wR = 0.0456 for 1883 observed reflections with Ⅰ > 2s(Ⅰ). In compound 1, the eight-coordinated Tb(III) atoms are bridged by carboxylate groups of ntb3– ligands to generate a one-dimensional Tb-carboxylate chain, which is further linked by the ntb3– ligands to form a three-dimensional structure. Compound 1 exhibits characteristic Tb(Ⅲ) luminescent emissions in the solid state.     

磷钨酸对对苯撑乙烯撑寡聚物-b-聚(2-乙烯基吡啶)自晶种行为的影响※

自晶种具有操作简便和聚合物组装基元适用性广的优点, 它是利用结晶-柔性(crystalline-coil)两嵌段共聚物活性结晶驱动自组装制备长度和组成可控的聚合物纳米纤维的重要策略. 而多金属氧酸及其衍生物具有独特的化学组成和几何结构以及优异的电/磁/光等物理性能. 以对苯撑乙烯撑寡聚物-b-聚(2-乙烯基吡啶)(OPV₅-b-P2VP₄₂)和磷钨酸(H₃O₄₀PW₁₂)分别为模型结晶-柔性两嵌段共聚物和多金属氧酸, 系统考察了磷钨酸对OPV₅-b-P2VP₄₂自晶种行为的影响. 研究发现OPV₅-b-P2VP₄₂的种子纤维在加热退火时的抗溶解能力随着磷钨酸的量增大而增强. 这可能是由于P2VP中的吡啶基元与磷钨酸金属原子间的络合作用, 而非吡啶与磷钨酸间的氢键作用, 使P2VP链间发生交联/聚集, 这不仅可平衡或减弱P2VP链间的排斥力和拉伸作用, 还将提升种子纤维断裂和解离所需的能量.