[Ni(phen)_3]_2(1,2,4,5-H_3BTC)_2(1,2,4,5-H_2BTC)·2H_2O的水热合成和晶体结构

近年来配位聚合物因其结构多样性及在催化、药物载体和气体吸附脱附等方面具有潜在的应用价值[1-3]而得到迅速的发展。本文在水热条件下,成功的合成出一例新型的一维超分子化合物,[Ni(phen)3]2(1,2,4,5-H3BTC)2(1,2,4,5-H2BTC)·2H2O。X-射线单晶衍射分析表明,化合物属于三斜晶系,P1空间群,晶胞参数为a=1.2403(3)nm,b=1.2907(3)nm,c=1.4512(3)nm,α=96.261(5)°,β=106.500(6)°,γ=105.061(4)°,V=2.1086(8)nm3,Z=2。在该化合物中,[Ni(phen)3]2+阳离子与[H3BTC]-和[H2BTC]2-阴离子通过静电引力、分子间氢键和分子内氢键,形成一个一维超分子链状结构。     

配合物[Co(C_9H_6NO)_3]·C_2H_5OH的醇热合成与表征

采用醇热合成法合成了标题化合物[Co(C9H6NO)3]·C2H5OH,测定了其晶体结构,晶体属于单斜晶系,P21/n空间群,晶体学参数为:a=1.1268(2)nm,b=1.3034(2)nm,c=1.6606nm(3),β=94.15(1)°,V=2.4325(8)nm3,Z=4,Dc=1.468Mg/m3,F(000)=1112。配合物中有三个N原子和三个O原子与中心离子Co(Ⅲ)配位,形成畸变的八面体配位环境。配合物通过分子间氢键作用与溶剂乙醇分子形成二维超分子的晶体结构。     

配合物[Co(C9H6NO)3]·C2H5OH的醇热合成与表征

采用醇热合成法合成了标题化合物[Co(C9H6NO)3]·C2H5OH,测定了其晶体结构,晶体属于单斜晶系,P21/n空间群,晶体学参数为:a=1.1268(2)nm,b=1.3034(2)nm,c=1.6606nm(3),β=94.15(1)°,ν=2.4325(8)nm3,Ζ=4,Dc=1.468Mg/m3,F(000)=1112.配合物中有三个N原子和三个O原子与中心离子Co(Ⅲ)配位,形成畸变的八面体配位环境.配合物通过分子间氢键作用与溶剂乙醇分子形成二维超分子的晶体结构.     

配合物[Co(C_9H_6NO)_3]·C_2H_5OH的醇热合成与表征

采用醇热合成法合成了标题化合物[Co(C9H6NO)3]·C2H5OH,测定了其晶体结构,晶体属于单斜晶系,P21/n空间群,晶体学参数为:a=1.1268(2)nm,b=1.3034(2)nm,c=1.6606nm(3),β=94.15(1)°,V=2.4325(8)nm3,Z=4,Dc=1.468Mg/m3,F(000)=1112。配合物中有三个N原子和三个O原子与中心离子Co(Ⅲ)配位,形成畸变的八面体配位环境。配合物通过分子间氢键作用与溶剂乙醇分子形成二维超分子的晶体结构。     

超分子化合物(C12H9N2)(ClO4)的合成及晶体结构

合成了超分子化合物(C12H9N2)(ClO4),该化合物晶体属三斜晶系,P1空间群,晶胞参数是:a=0.58033(7)nm,b=0.9874(2)nm,c=1.0630(2)nm,α=93.22(2)°,β=101.41(1)°,γ=98.04(1)°,V=0.5836(2)nm3,Mr=280.66,Dc=1.597g/cm3,Z=2.邻菲咯啉分子中一个N原子被质子化,并和相邻分子的高氯酸根中的O原子形成氢键,相邻的邻菲咯啉分子间通过π-π堆积把化合物扩展为二维超分子结构.     

基于[P_2W_(18)O_(26)]~(6-)的一个超分子化合物的合成与结构研究

利用水热合成法合成出一个新的多酸化合物[(biim)2(H6P2W18O_(62)]·12H_2O(1),通过元素分析、红外和X-射线单晶衍射对其结构进行了表征。1为单斜晶系,C2/c空间群,a=2.36923(8)nm,b=1.33013(5)nm,c=2.18740(7)nm,β=97.457(3)°,V=7.0387(4)nm3,Z=4。氢键作用将化合物连接成为三维的超分子结构。     

超分子化合物(C10H10N2)Co（SCN）4的合成、晶体结构和热稳定性

在室温下合成了一个新的超分子配合物(C10H10N2)Co(SCN)4,通过元素分析、红外和单晶X-射线进行了表征。标题化合物属于正交晶系,P 21 21 2空间群,a=1.283 32(11)nm、b=1.297 53(12)nm、c=0.544 12(5)nm、V=0.906 04(14)nm3、Z=2。在化合物中,每个Co2+离子与4个SCN-的4个N原子形成变形的四面体几何构型、4,4’-联吡啶的两个氮原子双质子化,并与SCN-的S原子形成N—H…S氢键,构成一维氢键超分子链。通过热重分析研究该化合物的热稳定性。     

氢键连接的二维超分子化合物[(Bi_2Cl_4I_6)(H_2tmdp)_2(CH_3OH)_4]的合成与晶体结构

合成了标题化合物,并对其结构进行了X-射线单晶衍射测定。该化合物属三斜晶系,空间群P1,晶胞参数a=1.1690(2)nm,b=1.2025(2)nm,c=1.1114(2)nm,α=116.07(3)°,β=101.17(3)°,γ=88.21(3)°,Z=1。晶体结构中,每个铋离子均呈现出六配位并与另一铋离子通过共用卤素离子形成双核[Bi2Cl4I6]4-配阴离子,1,3-二(4-哌啶基)丙烷完全质子化形成[H2tmdp]2+配阳离子,配阴离子[Bi2Cl4I6]4-、配阳离子[H2tmdp]2+以及溶剂CH3OH分子之间通过复杂的氢键形成二维层状超分子结构。     

氧钒配合物[VO2(C10H8N2)2]·NH4HSO4的合成、晶体结构和荧光性能

在80℃下合成了1个新的标题化合物,通过元素分析、红外和单晶X-射线进行了表征。标题化合物属于三斜晶系,P-1空间群,a=0.671 14(9)nm,b=1.165 88(14)nm,c=1.401 83(18)nm,α=96.410 0(10)°,β=94.825 0(10)°,γ=97.901(2)°,V=1.074 2(2)nm3,Z=2。配合物由1个VO2、两个2,2’-联吡啶分子和1个NH4HSO4构成,NH4HSO4分子通过氢键在a方向形成一维超分子链状结构,通过荧光光谱研究了该化合物的荧光性质。     

乙醇合4,4′-(2-氟苯基)-双(3-甲基-1-苯基-5-吡唑啉酮)甲烷的合成及其晶体结构

标题化合物C27H23FN4O2(C2H5OH)是由2分子1-苯基-3-甲基-5-吡唑啉酮和1分子2-苯甲醛微波辐射4 m in,用乙醇重结晶得到。在该化合物的晶体结构中,一个结构单元包含1分子4,4′(2-氟苯基)双(1-苯基-3-甲基-5-吡唑啉酮)甲烷和1分子乙醇。结构通过X射线衍射法确定,其晶体属于单斜晶系,P21/c空间群,Mr=500.56,a=0.949 6(19)nm,b=2.217 4(4)nm,c=1.285 4(3)nm,β=100.71(3)°,V=2.659 5(10)nm3,dc=1.250 g/cm3,Z=4,F(000)=1 056,μ=0.087 mm-1,最终偏差因子分别为R=0.059 1,wR=0.149 9,分子之间通过相邻分子间形成的N—H…O和O—H…N氢键相连。     

镀银镍粉/硅橡胶高导电复合材料的制备及性能研究

研究镀银镍粉体积分数对镀银镍粉/硅橡胶高导电复合材料性能的影响。结果表明:随着镀银镍粉体积分数增大,复合材料的邵尔A型硬度增大,拉断伸长率快速减小,体积电阻率减小并出现明显逾渗现象;当镀银镍粉体积分数为0.44时,复合材料具有良好的导电稳定性和优异的电磁屏蔽效能,但耐电化学腐蚀性能较差。     

Victrex® poly(ethersulfone) (PES) and Victrex® poly(etheretherketone) (PEEK)

Properties of two high performance engineering thermoplastics, amorphous polyethersulfone (PES) and semicrystalline polyetheretherketone (PEEK), are discussed. Both resins can be processed by conventional techniques, compounded with high performance fibers, and have high service temperature (up to 300°C). Due to the amorphous character PES can be dissolved and spray coated into metals.     

Photopyroelectric Spectroscopic Studies of ZnO-MnO(2)-Co(3)O(4)-V(2)O(5) Ceramics

Photopyroelectric (PPE) spectroscopy is a nondestructive tool that is used to study the optical properties of the ceramics (ZnO + 0.4MnO(2) + 0.4Co(3)O(4) + xV(2)O(5)), x = 0-1 mol%. Wavelength of incident light, modulated at 10 Hz, was in the range of 300-800 nm. PPE spectrum with reference to the doping level and sintering temperature is discussed. Optical energy band-gap (E(g)) was 2.11 eV for 0.3 mol% V(2)O(5) at a sintering temperature of 1025 °C as determined from the plot (ρhυ)(2)versushυ. With a further increase in V(2)O(5), the value of E(g) was found to be 2.59 eV. Steepness factor 'σ(A)' and 'σ(B)', which characterize the slope of exponential optical absorption, is discussed with reference to the variation of E(g). XRD, SEM and EDAX are also used for characterization of the ceramic. For this ceramic, the maximum relative density and grain size was observed to be 91.8% and 9.5 μm, respectively.     

Calcium silicate hydrate (II) (“C-S-H(II)”)

This semicrystalline phase, originally named ‘calcium silicate hydrate(II)’ by Taylor (1950), has been studied with X-rays, electron optics, chemical investigation of silicate anion type, infrared spectra, and thermal methods. It is structurally related to jennite (C₉S₆H₁₁) and probably also to the fibrous CSH of cement pastes, the three phases forming a sequence of decreasing crystallinity. The specimen studied had approximate composition C₂SH_3.2 after standing over saturated CaCλ₂ at about 15°C. CSH(II) contains metasilicate chains and pyrosilicate groups and has a disordered layer structure. Much of the water can be lost reversibly without significant change in lattice parameters.     

Photooxidative stability of substituted poly(phenylene vinylene) (PPV) and poly(phenylene acetylene) (PPA)

The addition of side groups to improve the photooxidative stability of polymers used in polymer-based light-emitting diodes (LEDs) is explored. Infrared spectroscopy and computational chemistry techniques are used to study the effects of chemical substitution of the reactive vinylene moiety in poly(phenylene vinylene) (PPV). The bond order of the vinylene group in small oligomers is calculated using semiempirical techniques to assess the improvement in stability toward oxidants such as singlet oxygen. We find that PPV dimers allow relative comparisons across a range of possible substitutions. Experimental results correlate well with these calculations. The addition of electron-withdrawing substituents, such as nitrile groups, to the vinylene moiety is found to be particularly effective in reducing the reactivity of alkoxy-substituted PPV toward singlet oxygen. The photooxidative stability of a poly(phenylene acetylene) (PPA) derivative is also studied. It appears that this family of polymers is more stable toward photooxidation than are its PPV analogs. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 2451–2458, 1998     

Chemical cross-linking of conducting poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) using poly(ethylene oxide) (PEO)

Hybrid films of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) were prepared with different molecular weights of poly(ethylene oxide) (PEO). The cross-linking reaction between PEO and PEDOT:PSS was performed at high temperature and confirmed by using differential scanning calorimeter (DSC), contact angle measurement, and solid-state ¹H NMR. The effect of chemical reaction on the conductivity and morphology of these hybrid films was studied by using 4-point probe and atomic force microscope (AFM), respectively. As-spun PEO/PEDOT:PSS films have lower electric conductivity due to the addition of nonconductive PEO, and exhibits no molecular weight dependence on conductivity. After chemical cross-linking reaction at high temperature, only PEDOT:PSS films with lowest molecular weight PEO additives show enhanced conductivity with increasing reaction time. AFM result indicates that the heat-treated PEO/PEDOT:PSS hybrid films show grain-like morphology compared to ethylene glycol treated PEDOT:PSS films which shows continuous PEDOT domain. In the present work we demonstrate that the cross-linking reaction can be used to improve the wet stability of PEDOT:PSS nanofiber, showing good water resistance and excellent dimensional stability.     

Poly(butadiene-acrylic acid(g)acrylonitrile(g)acrylic acid)

Summary In the present work we describe, the synthesis and characterization of a new gel obtained by crosslinking a cooligomer of butadiene-acrylic acid (BuAA), by reaction with acrylonitrile and acrylic acid. The purified product was characterized by FTIR, elemental analyses and scanning electronic microscopy. The thermal properties were studied and swelling indexes were determined in different solvents and at different pH values. The capacity of poly(butadiene-acrylic acid(g)acrylonitrile(g)acrylic acid) [gel A] to separate different organic substances, such as amino acids and colorants, was determined.     

纳米粉体(CeO_2)_(0.9-x)(GdO_(1.5))_x(Sm_2O_3)_(0.1)的溶胶-凝胶低温燃烧合成

采用溶胶 -凝胶法与低温燃烧法相结合 ,合成了 (CeO2 ) 0 .9-x(GdO1 .5 ) x(Sm2 O3) 0 .1 系列粉体 .结果表明 :由硝酸盐与柠檬酸混合形成的凝胶 ,可在较低温度 (2 0 0～ 3 0 0℃ )点火并燃烧 ,其火焰温度达 90 0℃以上 .经TEM ,XRD测试 ,燃烧后即直接形成了粒径为 2 0～ 3 0nm ,具有萤石结构的单相粉体 ,由该粉体制备的固体电解质在中温下电导率为 5 .8× 10 - 2 S/cm ,组装的单个H2 -O2 燃料电池最大功率密度达 70mW /cm     

Finite strain behavior of poly(ethylene terephthalate) (PET) and poly(ethylene terephthalate)-glycol (PETG)

Uniaxial and plane strain compression experiments are conducted on amorphous poly(ethylene terephthalate) (PET) and poly(ethylene terephthalate)-glycol (PETG) over a wide range of temperatures (25-110 °C) and strain rates (.005-1.0 s⁻¹). The stress-strain behavior of each material is presented and the results for the two materials are found to be remarkably similar over the investigated range of rates, temperatures, and strain levels. Below the glass transition temperature (θ_g=80 °C), the materials exhibit a distinct yield stress, followed by strain softening then moderate strain hardening at moderate strain levels and dramatic strain hardening at large strains. Above the glass transition temperature, the stress-strain curves exhibit the classic trends of a rubbery material during loading, albeit with a strong temperature and time dependence. Instead of a distinct yield stress, the curve transitions gradually, or rolls over, to flow. As in the sub-θ_g range, this is followed by moderate strain hardening and stiffening, and subsequent dramatic hardening. The exhibition of dramatic hardening in PETG, a copolymer of PET which does not undergo strain-induced crystallization, indicates that crystallization may not be the source of the dramatic hardening and stiffening in PET and, instead molecular orientation is the primary hardening and stiffening mechanism in both PET and PETG. Indeed, it is only in cases of deformation which result in highly uniaxial network orientation that the stress-strain behavior of PET differs significantly from that of PETG, suggesting the influence of a meso-ordered structure or crystallization in these instances. During unloading, PETG exhibits extensive elastic recovery, whereas PET exhibits relatively little recovery, suggesting that crystallization occurs (or continues to develop) after active loading ceases and unloading has commenced, locking in much of the deformation in PET.