[Et_4NB_(12)H_(11)NHCOCH_2CONH_2]~-及bipyO_2的稀土混配配合物研究

将[Et_4]_2B_(12)H_(12)与丙二腈反应,生成化合物Et_4NB_(12)H_(11)NCCH_2CN,水解后得[Et_4NB_(12)H_(11)NHCOCH_2CONH_2]~-·[Et_4NBN]~-,该衍生物与稀土氯化物(LnCl_3)及2,2＇-联吡啶-N,N＇-二氧化物(bipyO_2)反应,合成了几种新型的混配稀土配合物Ln(bipyO_2)_4(Et_4NBN)_3(Ln=La,Nd,Sm,Gd,Dy,Ho,Er).元素分析确定了它们的组成,通过IR、UV、~1H NMR、ESR、摩尔电导测定及TG-DTA等对其性质进行了研究。     

稀土络合催化炔烃和开环聚合新进展

本文综述了我国首创开拓的稀土络台催化聚合在炔烃和开环聚合方面的新进展.用稀土络合催化剂可以使乙炔、苯乙块在室温下聚合制备高顺式含量和抗氧化稳定性良好的聚炔烃膜;可以使环氧乙烷、环氧丙烷、环氧氯丙烷和环硫丙烷聚合制备高分子量聚合物;可以使丙交酯聚合制备可控分子量聚合物.     

染料敏化太阳能电池Eu~(3+),Sm~(3+)掺杂TiO_2下转换光阳极的制备及性能

用溶胶-凝胶法制备了Eu,Sm共掺TiO_2粉体,将其与P25复合,制备了下转换光阳极,用于染料敏化太阳能电池,利用其下转换特性提高电池的光电性能.用荧光光谱对粉体的发光性能进行表征,荧光光谱显示:Eu,Sm共掺TiO_2粉体受463nm光激发可以发射550~700nm的可见光,具有下转换功能.当Eu~(3+)的摩尔掺杂含量为1%,Sm~(3+)的摩尔含量为0.5%时,制备的Eu~(3+),Sm~(3+)共掺下转换光阳极,短路电流达到14.08mA/cm2,与使用Eu~(3+)掺杂TiO_2的下转换光阳极电池相比,提高了32.08%,转换效率也达到5.29%.     

微波辐射无皂乳液聚合制备荧光乳液纳米粒子及其性能研究

以苯乙烯(St)为主要单体,对苯乙烯磺酸钠(NaSS)和可聚合稀土荧光配合物(Eu(AA)(BA)_2Phen)为功能性单体,通过微波辐射无皂乳液聚合制备了Poly(St-NaSS-Eu(AA)(BA)_2Phen)共聚物荧光乳液纳米粒子.利用红外光谱对共聚物的结构进行了证实;通过透射电子显微镜和扫描电子显微镜观察了粒子的形态、结构及大小;利用激光光散射粒度仪测试了粒子的大小及分布;结果发现所制备的共聚物荧光乳液纳米粒子呈大小均一的球形形状,粒径大小约为35 nm;采用荧光分光光度计测试,发现共聚物纳米粒子在595 nm和619 nm处出现Eu~(3+)的特征发射光谱,具有良好的荧光效果.     

Multimode Luminescence Tailoring and Improvement of Cs2NaHoCl6 Cryolite Crystals via Sb3+/Yb3+ Alloying for Versatile Photoelectric Applications

Lead-free halide double perovskites are currently gaining significant attention owing to their exceptional environmental friendliness, structural adjustability as well as self-trapped exciton emission. However, stable and efficient double perovskite with multimode luminescence and tunable spectra are still urgently needed for multifunctional photoelectric application. Herein, holmium based cryolite materials (Cs₂NaHoCl₆) with anti-thermal quenching and multimode photoluminescence were successfully synthesized. By the further alloying of Sb³⁺ (s-p transitions) and Yb³⁺ (f-f transitions) ions, its luminescence properties can be well modulated, originating from tailoring band gap structure and enriching electron transition channels. Upon Sb³⁺ substitution in Cs₂NaHoCl₆, additional absorption peaking at 334 nm results in the tremendous increase of photoluminescence quantum yield (PLQY). Meanwhile, not only the typical NIR emission around 980 nm of Ho³⁺ is enhanced, but also the red and NIR emissions show a diverse range of anti-thermal quenching photoluminescence behaviors. Furthermore, through designing Yb³⁺ doping, the up-conversion photoluminescence can be triggered by changing excitation laser power density (yellow-to-orange) and Yb³⁺ doping concentration (red-to-green). Through a combined experimental-theoretical approach, the related luminescence mechanism is revealed. In general, by alloying Sb³⁺/Yb³⁺ in Cs₂NaHoCl₆, abundant energy level ladders are constructed and more luminescence modes are derived, demonstrating great potential in multifunctional photoelectric applications.     

Elucidating strategic network dynamics through computational modeling

In this study we describe a comprehensive computational model of network dynamics (COM-NeD) and demonstrate how it may help us better understand and theorize the dynamics of strategic networks. Specifically, we model a population of firms characterized by idiosyncratic resource needs and productive capacities, while having to respond to the demands of external events by establishing ties and receiving needed resources from other firms. Through COM-NeD we investigate a set of established theoretical perspectives that represent distinct strategies for seeking and establishing interfirm ties. Rigorous computational experiments demonstrate the expected behavior of such a system under a broad range of assumptions. The results shed light on the complexity of strategic network dynamics, demonstrating novel interactions of firms’ internal resource capacity, relational search approaches, and external resource growth.

Synthesis and Structural Properties of Anhydrous Rare Earth Cinnamates, [RE(cinn)3]

Anhydrous rare earth tris(cinnamates) [RE(cinn)₃] (RE = La–Lu, Y and Sc and cinnH = trans‐cinnamic acid) were prepared by metathesis in water and by direct reaction of the metal with cinnamic acid in a 1,2,4,5‐tetramethylbenzene flux at ca. 200 °C. X‐ray crystal structure determinations and X‐ray powder data show that, in the solid state, the larger lanthanoids (La–Dy) form an isomorphous polymeric series consisting of homoleptic nine‐coordinate metal centres bonded to three chelating and bridging tridentate cinnamates. The late RE^III cinnamate (RE = Dy, Ho–Lu, Y) complexes also form linear one‐dimensional polymeric chains with all RE metal atoms being seven‐coordinate. The cinnamates are either bound tridentate bridging in a μ‐η²:η¹ fashion, or μ‐η¹:η¹ syn‐syn bidentate bridging. A structural break occurs at dysprosium which has been characterised in both crystallographic forms, and gives solely the late RE form when precipitated at 80 °C. Sc^III cinnamate was also isolated as an analytically pure precipitate which was, again, found to be anhydrous in nature. A structural change was identified by powder XRD between the late RE^III cinnamates and Sc^III cinnamate.     

[{Er(NC5H4COOH)(H2O)2}2(H5O2)(HgCl5)(HgCl4)2(H2O)2]n – Synthesis,Crystal Structure and Properties

The first heterometallic 4f‐5d inorganic‐organic metal‐isonicotinic acid hybrid [{Er(NC₅H₄COOH)(H₂O)₂}₂(H₅O₂)(HgCl₅)(HgCl₄)₂(H₂O)₂]_n ( 1 ) has been synthesized via hydrothermal reaction and structurally characterized. Complex 1 crystallizes in the space group C2/c of the monoclinic system with four formula units per unit cell: a = 24.194(3), b = 20.792(3), c = 15.289(4) Å, β = 128.39(2)°, V = 6028(2) ų, C₃₆H₄₇Cl₁₃Er₂Hg₃N₆O₂₀, M_r = 2280.94, D_c = 2.513 g/cm³, S = 0.929, μ(MoKα) = 11.017 mm^?1, F(000) = 4248, R = 0.0425 and wR = 0.0739. The crystal structure analysis reveals that the title complex is characteristic of a one‐dimensional chain‐like structure. Photoluminescent investigation reveals that the title complex displays interesting emissions. Optical absorption spectra of 1 reveal the presence of an optical gap of 3.45 eV. The magnetic properties show that complex 1 exhibits antiferromagnetic interactions.     

Ytterbium perfluorooctanesulfonate as an efficient and recoverable catalyst for the synthesis of trisubstituted imidazoles

Synthesis of trisubstituted imidazoles was successfully accomplished using rare earth(III) perfluorooctanesulfonates (RE(OPf)₃), RE = Sc, Y, La-Lu as catalysts in fluorous solvents. Ytterbium perfluorooctanesulfonates (Yb(OPf)₃) catalyze the high efficient synthesis of trisubstituted imidazoles in fluorous solvents. By simple separation, fluorous phase containing only catalyst can be reused several times.     

Synthesis, crystal structure, and physical properties of the monoclinic form of the R4Mo4O11 compounds (R=Yb and Lu) containing infinite chains of trans-edge-shared octahedral clusters

Polycrystalline samples and single crystals of the R₄Mo₄O₁₁ compounds (R=Yb and Lu) were synthesized by solid-state reactions at high temperature in sealed Mo crucibles. The structure of Lu₄Mo₄O₁₁ (a=10.5611(1), b=5.61930(5), c=15.6877 (2), β=99.5131(4) and Z=4) was determined by single crystal X-ray diffraction and refined by least squares on F² converging to R₁=0.0425, wR₂=0.0980 for 3508 intensities. Contrary to the R₄Mo₄O₁₁ compounds with lighter rare earths, which crystallize in the orthorhombic space group Pbam, the Yb and Lu compounds crystallize in the monoclinic space group P2/m. The R₄Mo₄O₁₁ compounds contain distorted infinite oxide-molybdenum chains of trans-edge-sharing Mo₆ octahedra diluted with the rare earths. Magnetic susceptibility measurements indicate that the oxidation state of the Yb atoms is +3, affording 14 metallic valence electrons per Mo₄ fragment and, the absence of localized moments on the Mo network. Resistivity measurements on single crystals show that the Yb₄Mo₄O₁₁ and Lu₄Mo₄O₁₁ compounds are small band-gap semi-conductors.