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61.
The imidazole covalently coordinated sandwich-type heteropolymngstates Na9[ {Na(H=O2}3{M(C3H4N2)}3( Sb W9O33)2]·xH=O(M=Ni^Ⅱ, Co^Ⅱ, Zn^Ⅱ, Mn^Ⅱ) were obtained by the reaction of Na2WO4·2H2O, SbCl3·6H2O, NiCl2·6H2O [MnSO4·H2O, Co(NO3)2·6H2O, ZnSO4·7H2O] and imidazole at pH≈7.5. The structure of Na9[{Na(H2O)2}3{Ni(C3H4N2)}3(SbW9O33)2]·32H2O was determined by single crystal X-ray diffraction. Polyanion [{Na(H2O)2}3{Ni(C3H4N2)}3(SbW9O33)2}3]^9- has approximate C3v symmetry, imidazole coordinated six-nuclear duster [{Na(H2O)2}3{Ni(C3H4N2)}3]^9+ is encapsulated between two (α-SbW9O33)^9-, the three rings of imidazole in the polyanion are perpendicular to the horizontal plane formed by six metals (Na-Ni-Na-Ni-Na-Ni) in the central belt, and x-stacking interactions exist between imidazoles of neighboring polyanions with dihedral angel of 60%. The compounds were also characterized by IR, UV-Vis spectra, TG and DSC, and the thermal decomposition mechanism of the four compounds was suggested by TG curves. 相似文献
62.
溶胶-凝胶法制备还原态K-Co-Mo催化剂的合成醇性能 总被引:2,自引:1,他引:2
应用溶胶-凝胶法制备了还原态K-Co-Mo催化剂, 比较了不同的组分和不同的反应条件对合成醇性能的影响。实验结果表明,适量钾和钴助剂的添加能显著提高催化剂合成醇的性能,尤其是提高了C2+醇的选择性。此外,反应温度、压力以及空速对合成醇影响明显,升高温度可以提高催化反应中低碳醇的收率,但选择性下降;增加压力和空速可以提高低碳醇的收率和选择性,对合成低碳醇有利。在230 ℃,6.0 MPa,14 400 h-1条件下,催化剂合成低碳醇的收率为375.4 g/kg·h,选择性为70.2%,C1OH/C2+OH为0.48。 相似文献
63.
在低钯含量活性非均布Pd/Al2O3催化剂上,实现了富氧条件下,氢部分选择性催化还原NO过程,低温、富氧条件下NO的转化率高达80%-100%。NO直接分解实验表明,600℃,NO分解转化率在无氧时为17.3%,有0.5%氧存在时接近于0。氢非选择性还原NO条件下,100℃以下,NO转化率为100%。根据实验结果及文献,推测了氢部分选择性还原NO过程中可能存在的反应,不同的反应温度下,NO脱除反应有所不同。在115℃以下,NO还原产物为NH3;115℃-155℃,NO还原产物为NH3、N2O和N2;155℃以上,NO还原产物中无NH3存在。NO还原反应与氢氧反应是平行的竞争反应。 相似文献
64.
微波辐照下无皂阳离子聚(St-MMA)高分子纳米粒子的制备和表征 总被引:10,自引:1,他引:10
讨论了微波辐照下 ,以丙酮 水为分散介质 ,利用阳离子型自由基引发剂偶氮二异丁基脒盐酸盐(AIBA)引发苯乙烯 (St)和甲基丙烯酸甲酯 (MMA)共聚 ,合成出表面带正电荷的P(St MMA)共聚物纳米粒子 ,考察了丙酮用量、单体和引发剂浓度对纳米粒子粒径、粒径分布和乳液稳定性的影响 .结果表明 ,丙酮 水的体积比由 0增加到 1 2 6∶1时 ,粒子的平均水化半径从 12 2 2 1nm降低到 2 4 6 8nm ,粒径分布变宽 ,乳液抗电解质稳定性逐渐增强 ;增加引发剂和共聚单体MMA的浓度 ,粒子的水化半径逐渐减小 ,粒径分散系数增大 . 相似文献
65.
Two New C—21 Steroidal Glycosides from Cynanchum aurichulatum 总被引:2,自引:0,他引:2
Two new C-21 steroidal glycosides, cynanauriculoside I and cynanauriculoside Ⅱ, were isolated from the roots of Cynanchum aurichulatum. Their structures were established using spectroscopic methods including one and two-dimensional NMR. 相似文献
66.
A novel super molecule [Na(C60H80O12)]+[Au(SCN)4]- was obtained by extraction of calix[4] arene (L) for an aqueous solution containing [AuCl4]-, and NaCl into CH2Cl2. The crystal structure and properties of the title super molecule were characterized by single-crystal X-ray diffraction, IR and 1H NMR spectra. The X-ray single crystal structure analysis shows that the crystal was Tetragonal system with space group P4/n and the unit cell parameters were as follows: a=2.880 8(18) nm, b=2.880 8(18) nm, c=2.292 4(5) nm, and final R indices [I>2σ(I)]: R1=0.048 5, wR2=0.106 1. CCDC: 243229. 相似文献
67.
Polyurethanes are one kind of relic protection materials commonly used. During artificial photo-ageing, three polyurethanes, HDI-based polyurethane, MDI-based polyurethane and TDI-based polyurethane, have been considered to undergo UV radiation. Photochemical degradation of the polyurethanes has been monitored by means of Fourier transform infrared spectroscopy with attenuated total reflection accessory (FTIR-ATR). It was proved that the mechanism of the photochemical degradation of polyurethanes might be the scissions of carbamate (urethane) groups and the re-reactions of radical groups formed in the scission reactions. From the experiment results HDI-based polyurethane, an aliphatic diisocyanate, could be considered to be more suitably used as relic protection materials among these three polyurethanes for its ageing products with less color. 相似文献
68.
Complex films of crosslinked poly(methylsiloxane-co-ethylene oxide) and lithium perchlorate were prepared. These solid state polymeric electrolytes show a markedly higher ionic conductivity, and excellent flexibility. The ionic conductivity of the network films closed to 10~(-5) Scm~(-1) at room temperature. The effects of Li~+ content, species and contents of crosslinking agents, molecular weight of poly(ethylene oxide) and temperature on the ionic conductivity of the network films were also investigated. 相似文献
69.
A polystyrene-bonded stannic chloride catalyst was synthesized by the method of lithium polystyryl combined with stannic chloride. This catalyst is a polymeric organometallic compound containing 0.25 mmol Sn (Ⅳ)/g catalyst. The catalyst showed sufficient stability and catalytic activity in organic reaction such as esterification, acetalation and ketal formation, and it could be reused many times without losing its catalytic activity. 相似文献
70.
A star network polymer with a pentaerythritol core linking four PEG-block polymeric arms was synthesized, and its corresponding gel polymer electrolyte based on lithium perchlorate and plasticizers EC/PC with the character being colorless and highly transparent has been also prepared. The polymer host was characterized and confirmed to be of a star network and an amorphous structure by FTIR, ^1H NMR and XRD studies. The polymer host hold good mechanical properties for pentaerythritol cross-linking. Maximum ionic conductivity of the prepared polymer electrolyte has reached 8.83 × 10 ^-4 S·cm^-1 at room temperature. Thermogravimetry (TG) of the polymer electrolyte showed that the thermal stability was up to at least 150 ℃. The gel polymer electrolyte was further evaluated in electrochromic devices fabricated by transparent PET-ITO and electrochromically active viologen derivative films, and its excellent performance promised the usage of the gel polymer electrolyte as ionic conductor material in electrochrornic devices. 相似文献