摘要:

AbstractFibrous crystals of boron‐containing MTW‐type zeolite have been hydrothermally synthesized in B2O3‐SiO2‐HF‐H2O gel system at 170 °C in 20 to 28 d by using 1, 4‐diazabicyclo[2.2, 2]octane (DABCO) and methylamine as the co‐template, and characterized with XRD, SEM, TEM, HRTEM and SAED. The results of characterizations show that B atoms are incorporated into the zeolite framework as tetrahedron of B(OSi)4. The fibrous single crystals of 5–50 μm in length and 100–500 nm in width inter‐grow along thec‐axis of the zeolite, and the one dimension 12 oxygen ring channels are perpendic

ISSN:1001-604X    

DOI:10.1002/cjoc.20040220202

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2004

数据来源: WILEY

摘要:

AbstractA series of KF/Al2O3catalyzed Michael‐addition reactions between malononitrile and α,β‐unsaturate cycloketones in DMF solution were studied. At room temperature, 2‐cyano‐3‐aryl‐3–(1, 2, 3, 4‐tetrahydronaphthalen‐1‐one‐2‐yl) propionitrile derivatives were synthesized by the reaction between 2‐arylmethylidene‐1, 2, 3, 4‐tetra‐hydronaphthalen‐l‐one and malononitrile. However, if the temperature was increased to 80 C, 2‐amino‐3‐cyano‐4‐aryl‐4H‐benzo[h]chromene derivatives were obtained in high yields. When the α,β‐unsaturated ketones were replaced by 2, 6‐biarylmethylidenecyclohexanone or 25‐biarylmethylidenecyclopentanone, another series of 2‐amino‐3‐cyano‐4H‐pyran derivatives was isolated successfully. The st

ISSN:1001-604X    

DOI:10.1002/cjoc.20040220203

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2004

数据来源: WILEY

摘要:

AbstractA method is presented for the synthesis of zeolite ZSM‐2 by adding zeolite X as seeds in the synthetic mixture containing both lithium and sodium. At the presence of zeolite X seeds, highly crystalline zeolite ZSM‐2 with composition of (0.3–0.7)Li2O·(0.7–0.3)Na2O·A12O3, · (2.5–4.0)SiO2anH2O can be obtained in a wide range of SiO2/Al2O3ratios from 2.5 to 16, and the optimum Li2O/(Li2O+Na2O) fraction is between 0.3 and 0.7. The ZSM‐2 products were characterized by XRD. SEM, IR.29Si MAS NMR and DTA/TG analysis etc. By29Si MAS NMR spectroscopy, it was found that ZSM‐2 contained nearly equal FAU and EMT phase, and the Si/Al ratios in FAU were slightly lower than those in EMT domains in most cases. The lithium form zeolite ZSM‐2 has comparable N2adsorption

ISSN:1001-604X    

DOI:10.1002/cjoc.20040220204

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2004

数据来源: WILEY

摘要:

AbstractThe new coordination polymer, [K(DNP)(H2O)0.5]n(DNP=2, 4‐dinitrophenol) was prepared by the reaction of 2,4‐dinitrophenol with potassium hydroxide. The molecular structure was determined by X‐ray single‐crystal diffraction analysis, FT‐IR techniques, and elemental analysis. The crystal is monoclinic, space group C(2)/c with the empirical formula of C6N2O5.5K,Mr=231.21. The unit cell parameters are as follows:a=2.0789(3) nm,b=1.2311(2) nm.c=0.7203(1) nm. β=109.611(15)°, V=1.7366(4) nm3, Z=4. 0, = 1.769 g/cm3, F(000)=936, μ (Mo Kα) =0.617 mm−1. The potassium ions coordinate with all the oxygen atoms of phenolic hydroxyl group and nitro‐group of different 2,4‐dinitrophenol (DNP) ligands with high coordination number, and form a god cross‐linked three‐dimensional net structure of which makes the complex with god stabilities. The thermal decomposition of [K(DNP)(H2O)0.5]nhas only an intense exothermic process in the temperature range of 338–343 °C corresponding to a mass loss of 75.029s. The final decomposition resid

ISSN:1001-604X    

DOI:10.1002/cjoc.20040220205

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2004

数据来源: WILEY

摘要:

AbstractThe constant‐volume combustion energy, ΔcU(GUDN, s, 298.15 K), enthalpy of solution in acetic ether, ΔHθmand kinetic behavior of the exothermic decomposition reaction of the title compound (GUDN) are determined by a precise rotating bomb calorimeter, a Calvet microcalorimeter and DSC, respectively. Its standard enthalpy of combustion, Δ, Hθm:(GUDN, s, 298.15 K), standard enthalpy of formation, Δ,Hθm(GUDN, s, 298.15 K) and kinetic parameters of the exothermic main decomposition reaction in a temperature‐programmed mode [the apparent activation energy (Ea) and pre‐exponential factor (A)]are calculated. The values of ΔcU(GUDN, s, 298.15 K), ΔHθm(GUDN, s, 298.15 K), Δ,Hθm(GUDN, s, 298.15 K) and ΔsolHθmof GUDN are (‐7068.64×2.37) I‐g (‐1467.66×0.50) kJ · mol−1, (‐319.76×0.58) kJ · mol−1and (165.737×0.013) kJ·mol−1, respectively. The kinetic model function in integral form and the value ofEaand A of the exothermic main decomposition reaction of GUDN are 220.20 kl · mol−1and 1021.18s−1, respectively. The critical tempera

ISSN:1001-604X    

DOI:10.1002/cjoc.20040220206

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2004

数据来源: WILEY

摘要:

AbstractA combined method of density functional theory (DFT) and statistics integral equation (SIE) for the determination of the pore size distribution (PSD) is developed based on the experimental adsorption data of nitrogen on activated mesocarbon microbead (AMCMB) at 77 K. The pores of AMCMB are described as slit‐shaped with PSD. Based on the PSD, methane adsorption and phase behavior are studied by the DR method. Both nitrogen and methane molecules are modeled as Lennard‐Jones spherical molecules. and the well‐known Steele's 10–4–3 potential is used to represent the interaction between the fluid molecule and the solid wall. In order to test the combined method and the PSD model, the Intelligent Gravimetric Analyzer (IGA‐003) was used to measure the adsorption of methane on the AMCMB. The DFT results are in good agreement with the experimental data. Based on these facts, we predict the adsorption amount of methane, which can reach 32.3wat 299 K and 4 MPa. The results indicate that the AMCMBs are a good candidate for adsorptive storage of methane and natural gas. In addition, the capillary condensation and hysteresis phenomenon of methane are also observed

ISSN:1001-604X    

DOI:10.1002/cjoc.20040220207

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2004

数据来源: WILEY

摘要:

AbstractBased on the Finnis‐Sinsclair (FS) many‐body potential model, the melting process of a system, which consists of 500 Cu atoms, controlled by period boundary condition has been simulated. The means of pair correlation function, mean square displacement and Honeycutt‐Anderson bonded pair have been used to characterize the melting behavior of Cu at different heating rates. The simulation indicates that melting point of metal Cu is 1444 K during a continuous heating process, and the calculated diffusion constant at the melting point is 4.31×10−‐9/s. These results are better than those from the EAM method, showing that the FS potential model works well in some disorder

ISSN:1001-604X    

DOI:10.1002/cjoc.20040220208

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2004

数据来源: WILEY

摘要:

AbstractThe 5‐parameter Morse potential (5‐MP for short) of the interaction system between an oxygen atom and palladium surface clusters was constructed. The adsorption and diffusion of an oxygen atom on low index surfaces Pd (100). Pd (111). Pd (110) and Pd (311) stepped surface were investigated in detail with 5‐MP. It is found that fcc and hcp sites on the (111) surface and (111) microfacets are equivalent. The calculation results show that O atom adsorbs in the three‐fold hollow site, and the long‐bridge site is a stable site both in regular Pd (110) surface and in the (1×2) missing‐row reconstruction structure. Moreover, in the study of O‐Pd (311) surface system, We conclude that there are two stable adsorption states (four‐fold site: H4, three‐fold site: Hn) on O‐Pd (311) surface and the three‐fold site (Hf) is the metastable adsorption. At low coverage oxygen atom favors the four

ISSN:1001-604X    

DOI:10.1002/cjoc.20040220209

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2004

数据来源: WILEY

摘要:

AbstractThe heteropolytungstate Na9[{Na(H2O)2}3{Cu(H2O)}3(BiW9O33) 42H2O is obtained by the reaction of Na2WO4·2H2O, Bi(NO3)3· 5H2O with CuCl2· 2H2O at pH≠6. The structure and chemical composition are determined by X‐ray diffraction analysis and elemental analysis. The crystal data and main structure refinement are:a= 1.410(3) nm, b=2.338(5) nm, c=3.173(6) nm, β=98.06(4)°.V= 10.354(35) nm3. monoclinic crystal system, space group:C2/c, Z = 4, R1= 0.0471.wR2= 0.0642 I>2σ(I)].R1=0.1371,wR2= 0.0868 (all data). [(Na(H2O)2}3{Cu(H2O)}3W9O33)2]9–hasD34symmetry. IR, UV‐vis spectra, TG curve and magnetic property of the complex were also discussed. The compound exhibits an antiferromagnetic coupling withJ= ‐8.0

ISSN:1001-604X    

DOI:10.1002/cjoc.20040220210

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2004

数据来源: WILEY

摘要:

AbstractSeveral new transition metal complexes using Schiff base containing pyridine and amide moieties (N, N′‐bis(ß‐salicylaliminoethyl)‐2, 6‐pyridinedicarboxylic amide, H1L) as the ligand have been prepared. Their compositions and structures are corroborated by elemental analysis. IR, W,1H NMR, DTA‐TG and molar conductivity data. Their anti‐bacterial activities have been studied by microcalorimetry. The result shows that the ligand and all complexes are potential anti‐bacteria reagent and their inhibitory capacities are concentration‐depended. The Mn complex has the strongest i

ISSN:1001-604X    

DOI:10.1002/cjoc.20040220211

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2004

数据来源: WILEY