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71.
研究了Nd~(3+)和Ho~(3+)的内、外消旋-双(苯基亚砜)乙烷配合物的固体和溶液(非水溶剂)的电子光谱,分析了可见范围的电子光谱并计算了光谱参数(b~(1/2)、δ和Ω_1)和f-f跃迂强度,指出了“超灵敏”跃迁的振子强度与配合物的共价程度及配位数相关。 相似文献
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通过一锅水热法制备了一系列磷改性Ni-Al-O催化剂(Px-Ni-Al-O),以O2为氧化剂,评价了系列催化剂的乙烷氧化脱氢制乙烯性能。结果表明,助剂P的掺入不仅可以减小NiO晶粒的尺寸,还影响了Ni和Al之间的相互作用。在350~475℃的温度范围内,P改性Ni-Al-O催化剂上乙烯选择性均高于未改性的催化剂,且适量P的引入还可以提高乙烷转化率。当反应温度为475℃时,P0.15-Ni-Al-O催化剂上乙烯选择性和收率分别为61.4%和31.9%。此外,P改性后的催化剂表现出较强的抗积碳性能,连续反应22 h不失活。 相似文献
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Jun Xia Xiao‐Lin Gong Xing Fan 《Acta Crystallographica. Section C, Structural Chemistry》2015,71(10):878-882
Assemblies of pyrazine‐2,3‐dicarboxylic acid and CdII in the presence of bis(1,2,4‐triazol‐1‐yl)butane or bis(1,2,4‐triazol‐1‐yl)ethane under ambient conditions yielded two new coordination polymers, namely poly[[tetraaqua[μ2‐1,4‐bis(1,2,4‐triazol‐1‐yl)butane‐κ2N4:N4′]bis(μ2‐pyrazine‐2,3‐dicarboxylato‐κ3N1,O2:O3)dicadmium(II)] dihydrate], {[Cd2(C6H2N2O4)2(C8H12N6)(H2O)4]·2H2O}n, (I), and poly[[diaqua[μ2‐1,2‐bis(1,2,4‐triazol‐1‐yl)ethane‐κ2N4:N4′]bis(μ3‐pyrazine‐2,3‐dicarboxylato‐κ4N1,O2:O3:O3′)dicadmium(II)] dihydrate], {[Cd2(C6H2N2O4)2(C6H8N6)(H2O)2]·2H2O}n, (II). Complex (I) displays an interesting two‐dimensional wave‐like structure and forms a distinct extended three‐dimensional supramolecular structure with the help of O—H...N and O—H...O hydrogen bonds. Complex (II) has a three‐dimensional framework structure in which hydrogen bonds of the O—H...N and O—H...O types are found. 相似文献
76.
Xitao Wang Zhong He Shunhe Zhong Xiufen Xiao 《天然气化学杂志》2007,16(2):173-178
Pd-MoO3/SiO2 catalyst has been prepared using the method of incipient wetness impregnation. The photo absorbing behaviors and chemisorbing properties of the catalyst have been characterized by UV-vis spectra and TPD-MS experiments. The results indicated that metal Pd loaded on MoOe/SiO2 has a significant effect on the photo absorbing performance of MoO3/SiO2, and an obvious blue shift of the absorption edge is produced. Under UV irradiation, the chemisorption state of CO2 undergoes decomposing process to form CO at 481 K, and a two-site adsorption state of ethane can be formed at around 496 K. Photo-oxidation of ethane using carbon dioxide can mainly produce propanal, ethanol and acetaldehyde in the temperature range of 353-423 K. The presence of metal Pd improves the catalytic activity remarkably. 相似文献
77.
ZnO could be a suitable catalyst for the oxidative conversion of CH4,C2H6 and C3H8.However,the main drawback is its thermal instability.Therefore,ZnO supported on ZrO 2,TiO2,γ-Al2O and SiO2 was investigated for the oxidative dehydrogenation of propane and ethane,and the oxidative coupling of methane.The stability of the supported ZnO is partially improved,but ZnO reacts with the support material,forming new compounds (Zn-zirconates,-titanates,-aluminates and-silicates),which already occurs below reaction temperature.This might also be the case for many other heterogeneous catalysts. 相似文献
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A series of group 12 metal coordination polymers with 1,2-bis(diphenylphosphino)ethane dioxide (dppeO2), {[ZnCl2(μ-dppeO2)]·CH2Cl2}n (1·CH2Cl2), [ZnBr2(μ-dppeO2)]n (2), [CdI2(μ-dppeO2)]n (4), [(HgI2)2(μ-dppeO2)]n (5), [Zn(SCN)(μ-SCN)(μ-dppeO2)]n (6), and [Cd(NO3)(μ-SCN)(μ-dppeO2)]n (7), have been synthesized and structurally characterized. The structures of the compounds are all based on an infinite 1D chain constructed by four-coordinate metal ions and dppeO2 ligands adopting the trans bridging coordination fashion. In the coordination polymers 1, 2 and 4, the halide ions act as terminal ligands, leading to discrete 1D chains with alternative MX2 and dppeO2 repeating units. The mercury compound 5 features a unique square-wave-like inorganic chain –[Hg(1)–I–Hg(2)–I]–, and the 1D HgI2(μ-dppeO2) chains are further linked by HgI2 bridges to form a 3D network. In the thiocyanate-containing compounds 6 and 7, the 1D chains are linked by one (6) or two (7) bridging SCN– ions to result in 2D layered structures. Solid-state emission spectra of the coordination polymers show different variations compared to the free dppeO2 ligand, such as enhancement (1, 2, 6 and 7), shift (3 and 4) and quenching (5) upon metal coordination. 相似文献