Synthesis and repellent properties of vinylidene fluoride-containing polyacrylates

Fluorinated polyacrylats with side group containing vinylidene fluoride (VDF) units (CF₃(CF₂)_n (CH₂CF₂)_m, n = 3, 5; m = 1, 2) were successfully synthesized. The water and oil repellency properties of these polymers are similar to those of fluorinated polyacrylate with side group containing long perfluorooctyl group (CF₃(CF₂)₇). The thermal telomerization of CF₃(CF₂)₅I and CF₃(CF₂)₃I with vinylidene fluoride (VDF) provided CF₃(CF₂)₅CH₂CF₂I (1b) and CF₃(CF₂)₃CH₂CF₂CH₂CF₂I (1c), respectively. The addition of 1b with ethylene followed by hydrolysis gave CF₃(CF₂)₅CH₂CF₂CH₂CH₂OH (2b). Treatment of 1c with ethyl vinyl ether in the presence of Na₂S₂O₄ followed by reduction produced CF₃(CF₂)₃CH₂CF₂CH₂CF₂CH₂CH₂OH (2c). Fluoroacrylates 3b-d were prepared by acrylation of the corresponding fluoroalcohols 2b-d. The semi-continuous process emulsion co-polymerization of 3a-d with octadecyl acrylate and 2-hydroxylethyl acrylate initiated by (NH₄)₂S₂O₈ in the presence of a mixture emulsifiers of polyoxyethylene(10)nonyl phenyl ether (TX-10) and sodium lauryl sulfate provided stable latexes 4a-d, respectively. The water and oil repellency properties of 4b (R_f: CF₃(CF₂)₅CH₂CF₂) and 4c (R_f: CF₃(CF₂)₃CH₂CF₂CH₂CF₂) containing vinylidene fluoride (VDF) units were similar to those of 4a (R_f: CF₃(CF₂)₇) containing long perfluoroalkyl group and much better than those of polymer 4d (R_f: CF₃(CF₂)₃) with short perfluoroalkyl chain. Thus, polyacrylates containing vinylidene fluoride units showed promising aspects as the alternatives to the currently used water and oil repellent agents with long perfluoroalkyl chains.     

Zr掺杂对PdO/Ce1-xPdxO2-δ催化剂CO和CH4催化氧化的影响

采用溶液燃烧法制备出PdO/PdO/Ce_1-xPd_xO_2-δ （PdO/CP）和PdO/Ce1-x-yPdxZryO₂-δ （PdO/CPZ）催化剂,通过硝酸处理去除催化剂表面的PdO物种得到对应的PdO/Ce_1-xPd_xO_2-δ （CP）和Ce1-x-yPdxZryO₂-δ （CPZ）催化剂。考究四种催化剂（PdO/CP、PdO/CPZ、CP、CPZ）对CO和CH₄的氧化活性,并计算得出表面PdO和Pdⁿ⁺物种的转化频率（TOF）。结果表明Zr的添加对PdO催化剂上CO和CH₄的催化氧化活性具有不同的影响。Zr的添加对PdO/CPZ和CPZ催化剂的CO催化活性具有明显的促进作用,前者归因于PdO/CPZ催化剂表面生成了更小颗粒的PdO粒子,后者归因于CPZ催化剂中含有更多的氧空位。对于CH₄的催化氧化,Pdⁿ⁺物种起到关键的作用。由于Zr的掺杂导致CeO₂的晶格中Pd物种的含量减少,致使PdO/CPZ催化剂和CPZ催化剂对CH₄氧化活性的降低。     

NaKV_2O_6的水热合成与结构

以水热法合成偏钒酸的复盐ＮａＫＶ２Ｏ６并测定晶体结构。ＮａＫＶ２Ｏ６晶体属单斜晶系，Ｃ２空间群，ａ＝１０．５６８（３），ｂ＝１０．０８２（２），ｃ＝５．８１０（２）Ａ，β＝１０３．８７（２）°，Ｖ＝６０１．０（３）Ａ３，Ｍｒ＝２５９．９７，Ｆ（０００）＝４９６，μ＝３７．３８ｃｍ（－１），Ｚ＝４，Ｄｃ＝２．８７ｇ·ｃｍ－３，Ｄｏ＝２．８５ｇ·ｃｍ（－３）。结构由重原子法解出，全矩阵最小二乘法修正至Ｒ＝０．０２９，Ｒω＝０．０４３。无水偏钒酸盐骨架为链状结构，其阴离子骨架由ＶＯ４四面体共顶点氧形成ＶＯ－３无限链，链间为平衡电荷的阳离子，阳离子与链之间靠静电引力结合在一起。     

Self-assembly of silver polymers based on flexible isonicotinate ligand at different pH values: syntheses, structures and photoluminescent properties

Two interesting coordination polymers, [Ag₈(IN)₆(NO₃)₂] 1 and [Ag(IN)(HIN)]_1/2 [Ag(IN)] 2 (HIN=isonicotinic acid) have been synthesized hydrothermally at different pH values. 1 crystallizes in the triclinic space group P-1, with , , , α=75.87(3)°, β=80.87(3)°, γ=76.50(3)°, and Z=2. Compound 1 is the first example of a bilayer framework, in which both single layers are connected by the bond interactions (Ag-O) between Ag from two two-dimensional (2D) single layers generated by the A building block and O atoms from one-dimensional (1D) chain constructed by the B building block, in which coordination modes of IN were reported for the first time. 2 crystallizes in the monoclinic space group P2(1)/c, with , , , β=92.90(3)°, V=1185.0(4) and Z=4. Compound 2 exhibits a 2D plywood-like structure assembled by hydrogen bonds and weak Ag-O interactions.     

Hydrothermal synthesis and crystal structural characterization of two new modified polyoxometalates constructed of positive and negative metal–oxo cluster ions

Two new interesting polyoxometalate derivatives 1 and 2 constructed of modified metal–oxo cluster ions carrying positive and negative changes, respectively, was hydrothermally prepared and structurally characterized by IR, ESR, XPS, elemental analysis and X-ray crystallography. The result of structure determination shows that compound 1 and 2 are isostructural and both contain polyoxocation and polyoxoanion, and both cation and anion are built on mixed Mo–V tetra-capped pseudo-Keggin units with P centre, [Mo₈V₈O₄₀(PO₄)]ⁿ⁻, bonded to four or two [Ni(2,2′-bipy)₂H₂O]²⁺ complexes, respectively, via terminal oxygen of the capping V atoms. Magnetism measurement indicates that there exists antiferromagnetic interaction in complex 1 and 2.     

新奇的双帽 pseudo-Keggin 结构磷钼钒酸盐的水热合成、晶体结构、性质及其量子化学计算

报道了一种新奇的磷钒酸盐[NH₄]₄H[PMo₈V₄^ⅣV₂^ⅤO₄₂]·24H₂O的合成方法,用元素分析、EPR、IR、UV谱和TG等手段进行了表征,并用X射线衍射法测定了晶体结构.结果表明,该杂多酸盐属于四方晶系,空间群P4/mnc,a=b=1.2592(2)nm,c=1.7565(4)nm,V=2.7848(8)nm³,Z=2.杂多阴离子具有双帽pseudoKeggin结构,不仅其中的8个金属位置被V和Mo无序占有,而且整个磷钼钒酸盐杂多阴离子的取向也是无序的.还应用EHMO方法研究了簇阴离子的电子结构.     

Ce1-xTbxO2-δ复合氧化物氧缺位的拉曼光谱研究

采用溶胶-凝胶法制备了Ce1-xTbxO2-δ复合氧化物, 利用不同Raman激发波长(514和785 nm), 结合X射线衍射(XRD)、氢气-程序升温还原(H2-TPR)和氧气-程序升温脱附(O2-TPD)表征, 考察了Ce1-xTbxO2-δ复合氧化物在O2, He和H2气氛下氧缺位的原位变化情况和CeO2的F2g特征Raman峰位的偏移. 实验结果表明, 随着Tb掺杂量的提高, 由于晶胞收缩使得CeO2的F2g特征Raman振动峰发生蓝移. 514 nm Raman激发波长反映了催化剂的表面信息, 而785 nm激发波长反映了整体信息. 正是由于表面和整体变化的不一致, 造成原位Raman实验过程中氧缺位浓度变化趋势的不同. 在He和H2气氛下, 由于温度升高时伴随着Ce1-xTbxO2-δ中O2气的脱出, 使复合氧化物的微观结构发生改变, 以致Ce0.9Tb0.1O2-δ中的氧缺位浓度(A587/A465)在785 nm激发波长下出现先升高后下降的现象.     

Structure characterization of several oxalate-bridged transition-metal coordination polymers

Four oxalate-bridged transition-metal supramolecular compounds [Co₂(im)₄(ox)₂] 1, [Co(im)₂(ox)] 2, [Mn(2,2′-bpy)(ox)] 3 and [Fe(H₂O)₂(ox)] 4 (im, imidazole; ox, oxalate; bpy, bipyridine) were obtained from the simple hydrothermal reactions of Mⁿ⁺oxL (M, transition metal; L, aromatic N-donor ligand) system. They all exhibit the 1-D chain structures, consisting of the (or ML²⁺) units linked by oxalate bridges. Interestingly, the 1-D oxalate chains in the title compounds are further self-assembled into the 3-D supramolecular networks through the interchain various secondary bonding interactions. Because the units adopt the different configuration, the oxalate chains show either zigzag type as in compounds 1–3 or linear type as in compound 4. Compounds 1 and 2 are isomeric, and only in packing modes of interchain im molecules there exists the difference.     

新的四帽Keggin结构的金属-氧簇合物[NiMo12O40H10{Ni(H2O)3}4]的水热合成与结构表征

多金属氧酸盐 (也称金属 -氧簇 )由于在催化、材料及医药等领域的应用日益广泛而备受关注 .近年来 ,一些新颖的非经典结构的化合物不断被合成出来 .如带二帽的 Keggin结构化合物 [V15O4 2 ]9- [1] ,[PV14 O4 2 ]9- [2 ] ,[As V14 O4 2 ]9- [3 ] ,[{ Mo8V7O4 2 } 2 ]14 - [4 ] ,     

Synthesis, structure and non-linear optical property of a copper(II) thiocyanate three-dimensional supramolecular compound

A novel copper(II) thiocyanate complex [Cu(im)₂(NCS)₂] 1 (im=imidazole) has been prepared and characterized by spectroscopic analysis and crystallographic method. This supramolecular compound exhibits a three-dimensional solid state structure constituted by N–HS hydrogen bonds and π–π stacking interactions. The compound in DMF solutions has a very strong third-order non-linear optical (NLO) behavior with absorption coefficient and refractive index ₂=1.18×10⁻¹¹ mw⁻¹, n₂=−9.00×10⁻¹⁶ m²w⁻¹, respectively, and third-order NLO susceptibility χ⁽³⁾ of 7.00×10⁻¹⁰ esu.