2008 Volume 19 Issue 11

First total synthesis of 10α-hydroxy-4-muurolen-3-one and its C10-isomer
Fu Qiang Bi , Li Jing Fang , Chen Xi Zhang , Yu Lin Li
2008, 19(11): 1265-1267  doi: 10.1016/j.cclet.2008.09.022
[Abstract](151) [FullText HTML] [PDF 262KB](0)
Abstract:
An efficient synthetic route to muurolane type sesquiterpenes starting from (R)-carvone,employing allylic diazene rearrange-ment and the ring closing methesis (RCM) reaction as key steps,is described.The first asymmetric total synthesis of (-)-10α-hydroxy-4-muurolen-3-one B and (-)-10β-hydroxy-4-muurolen-3-one C was accomplished.Through the total synthesis,the absolute configurations of the natural products A,B and C were established.
Synthesis and herbicidal activities of pyridyl sulfonylureas:More convenient preparation process of phenyl pyrimidylcarbamates
Ning Ma , Zhi Jin Fan , Bao Lei Wang , Yong Hong Li , Zheng Ming Li
2008, 19(11): 1268-1270  doi: 10.1016/j.cclet.2008.09.019
[Abstract](149) [FullText HTML] [PDF 200KB](0)
Abstract:
Four 4-monosubstituted pyrimidine pyridyl sulfonylureas were synthesized from pyridinesulfonamide and phenyl pyrimidyl-carbamate and screened for herbicidal activities.We also reported a convenient preparation process of phenyl pyrimidylcarbamates from pyrimidineamine and phenyl chloroformate.
Synthesis of new chiral 1,2,3,4-tetrahydroisoquinoline β-amino alcohols from L-DOPA
Geng Xu , Zhan Zhu Liu
2008, 19(11): 1271-1273  doi: 10.1016/j.cclet.2008.09.024
[Abstract](150) [FullText HTML] [PDF 245KB](0)
Abstract:
Four new chiral 1,2,3,4-tetrahydroisoquinoline-derived β-amino alcohols were synthesized from L-DOPA in good yields.The structures of the target compounds were confirmed by 1H NMR,13C NMR and MS.
Wet carbon-based solid acid/potassium permanganate as an efficient heterogeneous reagents for oxidation of alcohols under mild conditions
Arash Shokrolahi , Abbas Zali , Mohammad Hossein Kes
2008, 19(11): 1274-1276  doi: 10.1016/j.cclet.2008.09.020
[Abstract](152) [FullText HTML] [PDF 166KB](0)
Abstract:
Wet carbon-based solid acid and potassium permanganate were used as new reagents for oxidation of alcohols to their corresponding aldehydes and ketones in heterogeneous mixtures.The experiments were done moderately at mild condition and high yields in suitable times were obtained.
A green and efficient oxidation of benzylic alcohols using H2O2 catalyzed by montmorillonite K-10 supported CoCl2
Ali Ezabadi , Ghloam Reza Najafi , Mohammad M. Hashemi
2008, 19(11): 1277-1280  doi: 10.1016/j.cclet.2008.09.010
[Abstract](160) [FullText HTML] [PDF 261KB](0)
Abstract:
Primary and secondary benzylic alcohols were oxidized to the corresponding carbonyl compounds in good to high yields by environmentally friendly and green oxidant, H2O2 catalyzed by montmorillonite K-10 supported cobalt(II) chloride.
Synthesis and antitumor activity of N1-acetylamino-(5-alkyl/aryl-1,3,4-thiadiazole-2-y1)-5-fluorouracil derivatives
Kai Bo Zheng , Jun He , Jie Zhang
2008, 19(11): 1281-1284  doi: 10.1016/j.cclet.2008.09.021
[Abstract](153) [FullText HTML] [PDF 268KB](0)
Abstract:
A new series of N1-acetylamino-(5-alkyl/aryl-1,3,4-thiadiazole-2-y1)-5-fluorouracil derivatives were designed and synthesized.These compounds have not been reported in literature,and their structure chemical were confirmed by IR,1H NMR and MS (HRMS).The results of antitumor inhibitory activity test showed that some compounds possess more potent antitumor inhibitory activity than 5-fluorouracil.
Syntheses of molecular wires containing redox center:Reversible redox property and good energy level matching with Au electrode
Er Jing Wang , Cheng Liang Wang , Qing Meng , Hong Xiang Li , Wen Ping Hu , Dao Ben Zhu
2008, 19(11): 1285-1289  doi: 10.1016/j.cclet.2008.06.056
[Abstract](151) [FullText HTML] [PDF 365KB](0)
Abstract:
Molecular wires with tetrathiafulvalene (TTF) as redox center were synthesized and characterized.UV-vis spectra and cyclic voltammetry showed these wires had good reversible redox behavior under ambient conditions and their HOMO energy levels (~-5.0 eV) matched well with the Fermi level of Au (~-5.1 eV).
Total synthesis of bis-(2,3-dibromo-4,5-dihydroxyphenyl)-methane as potent PTP1B inhibitor
Jing Li , Shu Ju Guo , Hua Su , Li Jun Han , Da Yong Shi
2008, 19(11): 1290-1292  doi: 10.1016/j.cclet.2008.07.002
[Abstract](154) [FullText HTML] [PDF 221KB](0)
Abstract:
Protein tyrosine phosphatase 1B (PTP1B) plays an important role as a negative regulator and has been proved to be an effective target for the treatment of type 2 diabetes mellitus.Bis-(2,3-dibromo-4,5-dihydroxyphenyl)-methane 7 was first reported as a natural bromopbenol with significant inhibition against PTP1B which was isolated from red algae Rhodomela confervoides.Intrigued by its astonishing activity (IC50=2.4 μmol/L),compound 7 was synthesized with the overall yield of 24% and evaluated for its PTP1B inhibitory activity compared with natural compound.
Synthesis and characterization of fluorinated polyurethane with fluorine-containing pendent groups
Zhen Ge , Xing Yuan Zhang , Jia Bing Dai , Wei Hu Li , Yun Jun Luo
2008, 19(11): 1293-1296  doi: 10.1016/j.cclet.2008.07.014
[Abstract](145) [FullText HTML] [PDF 233KB](0)
Abstract:
A novel fluorinated polyurethane (FPU) with fluorine-containing pendent groups was prepared by using fluorinated polyether glycol (PTMG-g-HFP) as a soft segment,1,6-hexamethylene diisocyanate (HDI) or toluene diisocyanate (TDI) as a hard segment and 1,4-butanodiol (BDO) as a chain extender.FTIR,1H NMR,13C NMR and GPC were used to characterize the structure of the fluorinated polyurethane.Thermal stabilities of the fluorinated polyurethane and the corresponding hydrogenated polyurethane were studied by TGA.XPS analysis at two different sampling depths for the fluorinated polyurethane was used to investigate the surface compositions of FPU.The results showed the fluorine enrichment on the surface of FPU.
A practical synthesis of(-)fosfomycin from its enantiomer
Meng Zhang , Zheng Yu , Ji Jun Li , Da Li Yin
2008, 19(11): 1297-1300  doi: 10.1016/j.cclet.2008.07.020
[Abstract](162) [FullText HTML] [PDF 252KB](0)
Abstract:
(+)-cis-(1S,2R)-Epoxypropylphosphonic acid,the enantiomer of fosfomycin,which is the industrial side-product in the preparation of the antibiotic fosfomycin,was converted into (-)fosfomycin by a seven-step procedure.The esterification of the dihydroxyphosphonic intermediate was the key step.The title compound was obtained in good yield and its optical purity was up to the medicine quality standard of Chinese Pharmacopoeia.
A facile and convenient method for synthesis of alkyl thiocyanates under homogeneous phase transfer catalyst conditions
Ali Reza Kiasat , Rashid Badri , Soheil Sayyahi
2008, 19(11): 1301-1304  doi: 10.1016/j.cclet.2008.07.019
[Abstract](149) [FullText HTML] [PDF 237KB](0)
Abstract:
A simple and environmentally friendly method is described for the efficient conversion of alkyl halide to alkyl thiocyanate using tetrabutylammonium bromide (TBAB) as a phase transfer catalyst.The reactions occur in water and furnish the corresponding alkyl thiocyanate in high yields.No evidence for the formation of isothiocyanates as by-product of the reaction was observed and the products were obtained in pure form without further purification.
Microwave-accelerated synthesis of some 1-aroyl-3,5-dimethylpyrazoles
Aamer Saeed , Amara Mumtaz
2008, 19(11): 1305-1308  doi: 10.1016/j.cclet.2008.07.017
[Abstract](147) [FullText HTML] [PDF 230KB](0)
Abstract:
Rapid and highly efficient synthesis of some 1-aroy1-3,5-dimethylpyrazoles is achieved by the cyclocondensation of corresponding aroyl hydrazides with 2,4-pentanedione in the absence of solvent and catalyst,under microwave irradiation.The reaction proceeds rapidly and is completed within 40-70 s giving a series of 1-aroy1-3,5-dimethylpyrazoles derivatives in high yields.All of the compounds have been characterized by FTIR,1H NMR,and mass spectroscopy.
An effective synthesis of β-aryl substituted isotetronic acids via Suzuki coupling
Huan Sheng Chen , Xia Ping Ma , Zhi Ming Li , Quan Rui Wang , Feng Gang Tao
2008, 19(11): 1309-1311  doi: 10.1016/j.cclet.2008.09.016
[Abstract](147) [FullText HTML] [PDF 216KB](0)
Abstract:
lsotetronic acids are of great agricultural and pharmacological relevance and occur in a number of natural products.A convenient synthetic pathway to β-aryl substituted isotetronic acid derivatives was developed via Suzuki cross-coupling of the corresponding β-bromo substituted isotetronic acid derivatives with arylboronic acids under palladium acetate catalysis.Good to excellent yields have been achieved.
Porous epoxy thermosets obtained by a reaction-induced process and their characterizations
Hao Ai , Kai Xu , Huan Liu , Ming Cai Chen
2008, 19(11): 1312-1314  doi: 10.1016/j.cclet.2008.09.026
[Abstract](155) [FullText HTML] [PDF 1185KB](0)
Abstract:
A novel reaction-induced method with the aid of solvent for porous thermosetting epoxy was first carried out.Investigations of pore structure using scanning electron microscope (SEM) showed that porous epoxy networks with average pore size ranging from 3 to 20 μm were obtained.The pore structure generated by this method can be tailored by changing the solvent content.
Flavonoid triglycosides from the seeds of Camellia oleifera Abel
Li Chun Du , Bei Li Wu , Jian Min Chen
2008, 19(11): 1315-1318  doi: 10.1016/j.cclet.2008.09.011
[Abstract](139) [FullText HTML] [PDF 323KB](0)
Abstract:
Two flavonoid triglycosides,kaempferol 3-O-{β-D-glucopyranosyl-(1→2)-[a-L-rhamnopyranosyl-(1→6)]-β-D-glucopyra-noside} (1) and kaempferol 3-O-{β-D-xylopyranosyl-(1→2)-[a-L-rhamnopyranosyl-(1→6)]-[β-D-glucopyranoside} (2),were isolated from the seed of Camellia oleifera Abel.The absolute configuration of compound 1 was established on the basis of its X-ray analysis.Their cytotoxic activities and anti-HIV-RT activities were evaluated.
One chloro-furoeremophilanoid and two new natural dimers from Ligularia atroviolacea
Jun Zhao , Hao Wu , Ke Xin Huang , Shu Yun Shi , Hua Peng , Xian Feng Sun , Liu Rong Chen , Qun Xiong Zheng , Qi Jun Zhang , Xiao Jiang Hao , Joachim Stöckigt , Xiao Kun Li , Yu Zhao , Jia Qu
2008, 19(11): 1319-1322  doi: 10.1016/j.cclet.2008.09.013
[Abstract](151) [FullText HTML] [PDF 410KB](0)
Abstract:
Three new compounds,including one chloro-furoeremophilanoid (1),one eremophiladiolide (2),a rare dimer of nor-furoeremophilanoid,ligulatrovine A (3),and a known furoeremophilanolide (4),were isolated from Ligularia atroviolacea.The structures of compounds 1-4 were elucidated by spectroscopic methods including ID and 2D NMR experiments as well as X-ray diffraction study.
Two new tetralone derivatives from the culture of Xylaria hypoxylon AT-028
Wen Gu , Hui Ding
2008, 19(11): 1323-1326  doi: 10.1016/j.cclet.2008.09.006
[Abstract](156) [FullText HTML] [PDF 328KB](3)
Abstract:
Two new tetralone derivatives named xylariol A (1) and B (2) were isolated from the EtOAc extract of the culture broth of Xylaria hypoxylon AT-028 (Xylariaceae),and their structures were elucidated by MS,IR,ID-and 2D-NMR spectra,and by X-ray diffraction analysis. 1 and 2 showed moderate cytotoxic activities against Hep G2 cells in the in vitro cytotoxic assay with ICso values of 22.3 and 21.2 μg/mL,respectively.
Two new benzofuran lignan glycosides from Gelsemium elegans
Wei Hua , Qing Chun Zhao , Jia Yang , Guo Bing Shi , Li Jun Wu , Tao Guo
2008, 19(11): 1327-1329  doi: 10.1016/j.cclet.2008.09.012
[Abstract](150) [FullText HTML] [PDF 239KB](0)
Abstract:
Two new benzofuran lignan glycosides,gelsemiunoside A and B,were isolated from the whole plant of Gelsemium elegans Benth.Their structures were elucidated on the basis of spectroscopic evidence.Furthermore,gelsemiunoside A and B were shown a potent cytotoxic activity by suppressing the proliferation of A375-S2 cells.
Layered zirconium phosphate-supported metalloporphyrin:Synthesis and catalytic application
Hai Yan Wang , Wei Dong Ji , Da Xiong Han
2008, 19(11): 1330-1332  doi: 10.1016/j.cclet.2008.07.024
[Abstract](151) [FullText HTML] [PDF 285KB](0)
Abstract:
This paper reports a new route for the preparation of layered alpha-zirconium phosphate (α-ZrP)-supponed metalloporphyrin MnTMPyp.MnTMPyP was intercalated into α-ZrP using α-ZrP·BA (i.e.pre-intercalated buitylamine was arranged by a monolayer mode in α-ZrP) as a starting material.The catalytic activity of the supported material for homovanillic acid (HVA) oxidation was investigated.The results showed a promising layered material-supported catalyst in catalytic system.
Simultaneous laser-induced fluorescence and contactless-conductivity detection for microfluidic chip
Feng Shen , Meng Yang , Yong Yu , Qi Kang
2008, 19(11): 1333-1336  doi: 10.1016/j.cclet.2008.06.057
[Abstract](167) [FullText HTML] [PDF 345KB](0)
Abstract:
A combined detection system involving simultaneous LIF and contactless-conductometric measurements at the same place of the microfluidic chip was described.The LIF measurement was designed according to the confocal principle and a moveable contactless-conductivity detector was used in C4D.Both measurements were mutually independent and advantageous in analyses of mixtures.Various experimental parameters affecting the response were examined and optimized.The performances were demonstrated by simultaneous detection of Rhodamine B.And the results showed that the combined detection system could be used sensitively and reliably.
Determination of ziram in vegetable samples by square wave voltammetry
Ping Qiu , Yong Nian Ni
2008, 19(11): 1337-1340  doi: 10.1016/j.cclet.2008.07.013
[Abstract](155) [FullText HTML] [PDF 220KB](0)
Abstract:
The electrochemical behaviour and electrode reaction mechanism of ziram (zinc-dimethyl dithiocarbamate) on a hanging mercury drop electrode were investigated in Britton-Robinson (B-R) buffer by using cyclic and square wave voltammetry (SWV).Based on these studies a voltammetric method for determination of ziram was developed and applied to determine the ziram in synthetic and spiked vegetable samples,satisfactory results were obtained in both eases.
Protein surface recognition of the novel tetra-carboxylphenyl calix[4]arene to cytochrome c
Wen Ting An , Yong Jiao , Xiao Hua Sun , Chuan Dong , Shao Min Shuang , Ping Fang Xia , Man Shing Wong
2008, 19(11): 1341-1344  doi: 10.1016/j.cclet.2008.09.004
[Abstract](154) [FullText HTML] [PDF 894KB](0)
Abstract:
The interaction of the novel tetra-carboxylphenyl calix[4]arene (TCPC) with the bovine heart cytochrome c (Cc) was first investigated by fluorescence spectroscopy and molecular modeling methods.The formation of a stable 1:1 complex was monitored by fluorescence titration,and its binding constant is 1.916×107 L mol-1. Molecular modeling reveals the recognition mechanism of TCPC to the Cc surface,that is,the electrostatic interaction drives TCPC to the Cc surface,and the van der Waals interaction orientates TCPC parallel to the cleft of Cc.
High-speed countercurrent chromatography for purification of single-walled carbon nanotubes
Ying Cai , Zhi Hong Yan , Ying Chun Lv , Min Zi , Li Ming Yuan
2008, 19(11): 1345-1348  doi: 10.1016/j.cclet.2008.07.018
[Abstract](153) [FullText HTML] [PDF 1488KB](0)
Abstract:
A new chromatographic purification of single-walled carbon nanotubes using high-speed countercurrent chromatography is reported.The purification was accomplished on the basis of experiment that dispersed the single-walled carbon nanotubes with sodium dodecyl sulfate,and the result mixture was separated using the two phase system composed of n-butanol/water=1/1 (v/v).The sizes of SWNTs separated were observed by scanning electron microscopy.The results demonstrated that the high-speed countercurrent chromatography possessed a good efficency for purification of single-walled carbon nanotubes.
Isolation and purification of phenylethanoid glycosides from plant extract of Plantago asiatica by high performance centrifugal partition chromatography
Li Li , Chun Ming Liu , Zhi Qiang Liu , Jing Wang
2008, 19(11): 1349-1352  doi: 10.1016/j.cclet.2008.09.002
[Abstract](154) [FullText HTML] [PDF 339KB](0)
Abstract:
Two phenylethanoid glycosides (PhGs) were isolated and purified from the aerial parts of Plantago asiatica for the first time by high performance centrifugal partition chromatography (HPCPC) using ethyl acetate-n-butanol-ethanol-water (0.5:0.5:0.1:1,v/v/v/v). A total of 45.6 mg of compound 1 and 293.8 mg of compound 2 were purified from 1341 mg of the n-butanol extract of P.asiatica.The structures of the two PhGs were tentatively identified as plantamajoside and acteoside or isoacteoside by electrospray ionization multi stage tandem mass spectrometry (ESI-MSn) in the negative ion mode.
A highly sensitive colorimetric and ratiometric sensor for fluoride ion
Zhao Wu Xu , Jin Tang , He Tian
2008, 19(11): 1353-1357  doi: 10.1016/j.cclet.2008.09.005
[Abstract](152) [FullText HTML] [PDF 688KB](0)
Abstract:
A new benzoimidazole-naphthalimide derivative 4 was synthesized and its photophysical properties were studied.This compound showed highly selectively and sensitive colorimetric and ratiometric sensing ability for fluoride anion.
In-situ copolymerization of aniline with alkyl amine by APS:Kinetics and application
M. Rashid , Shams Qamar Usmani , Suhail Sabir
2008, 19(11): 1358-1362  doi: 10.1016/j.cclet.2008.06.045
[Abstract](147) [FullText HTML] [PDF 355KB](0)
Abstract:
The kinetic study of in-situ copolymerization of aniline with o-and p-methylaniline by ammonium persulfate (APS) has been carried out.UV-vis spectroscopic method was used to investigate the course of copolymerization.Structural characterization was studied by FT-IR spectral analysis.The electronic spectra of the copolymers poly(aniline-co-p-toluidine) and poly(aniline-co-o-tolnidine) show blue shift.The shift has been observed in the bands corresponding to π→π* transition as well as in the exciton transition.The increase in absorbance recorded during the reaction for different concentration of aniline,o-and p-toluidine at various intervals of time of polymerization reaction indicates a growth in the polymer formation.The resulting first-order rateconstant was used to calculate the rate of copolymer formation using the rate equation-d[A]/dt=kcn.
Sphere-to-rod transition of short-chain PEO-b-PDMS-b-PEO in aqueous solution induced by copolymer concentration
Xiao Li Zhan , Bi Chen , Qing Hua Zhang , Ling Min Yi
2008, 19(11): 1363-1366  doi: 10.1016/j.cclet.2008.07.012
[Abstract](154) [FullText HTML] [PDF 2095KB](0)
Abstract:
A short-chain triblock copolymer EO9-DMS7-EO9 was synthesized by coupling reaction of allyl-terminated poly(ethylene oxide) and Si-H-terminated poly(dimethylsiloxane).The structure and purity of synthesized copolymer was carefully character-ized.Self-assembly behavior of EO9-DMS7-EO9 triblock copolymer in water was investigated.And it was found that along with the increase of copolymer concentration,morphology of self-assembled aggregates transits from sphere to rod.A plausible under-standing of the morphology transition for the investigated triblock copolymer was proposed.
Microstructure and corrosion behavior of electroless deposited Ni-P/CeO2 coating
Hui Ming Jin , Shi Hang Jiang , Lin Nan Zhang
2008, 19(11): 1367-1370  doi: 10.1016/j.cclet.2008.06.040
[Abstract](160) [FullText HTML] [PDF 1853KB](0)
Abstract:
Electroless Ni-P/nano-CeO2 composite coating was prepared in acidic condition,and its microstructure and corrosive property were compared with its CeO2-free counterpart.Scanning electronic microscopy (SEM) and X-ray diffraction (XRD) spectrometer were used to examine surface morphology and structure of the as-plated coating.Differential scanning calorimeter (DSC) and transmission electronic microscopy (TEM) were used to study the coating's phase change at high temperature.The coating's corrosive behavior in 3%NaCI+5%H2SO4 solution was also investigated.The results showed that Ni-P coating had partial amorphous structure mixed with nano-crystals,while the Ni-P/CeO2 coating had perfect amorphous structure.In high-temperature condition,Ni3P precipitation and Ni crystallization took place in both coatings but at different temperatures,while the Ni-P/CeO2 coating had sintered phase of NiCe2O4 spinels.The anti-corrosion property was better in the CeO2-containing coating,and this was due to its less liability to undergo local-cell corrosion than its CeO2-free counterpart.Ni-P/CeO2 coating's pure amorphous structure was the result of Ni's hindered crystal-typed deposition and P's promoted deposition.
A novel approach to large-scale formation of through-hole porous anodic aluminum template
Ya Nan Zhang , Miao Chen , Zhi Lu Liu , Yan Chun Zhao
2008, 19(11): 1371-1374  doi: 10.1016/j.cclet.2008.09.008
[Abstract](156) [FullText HTML] [PDF 4088KB](0)
Abstract:
A novel anodic oxidization equipment was designed to fabricate a large number of porous anodic alumina (PAA) templates in one time.This approach improved the efficiency of the preparation of the PAA templates remarkably in a normal lab and is expected to be used for the large-scale production in the future.
Research on the explosion characteristics of chlorine dioxide gas
Ri Ya Jin , Shuang Qi Hu , Ying Hao Zhang , Tao Bo
2008, 19(11): 1375-1378  doi: 10.1016/j.cclet.2008.09.001
[Abstract](160) [FullText HTML] [PDF 385KB](1)
Abstract:
The explosion characteristics of chlorine dioxide gas have been studied for the first time in a cylindrical exploder with a shell capacity of 201.The experimental results have indicated that the lower concentration limit for the explosive decomposition of chlorine dioxide gas is 9.5% ([ClO2]/[airl]),whereas there is no corresponding upper concentration limit.The maximum pressure of explosion relative to the initial pressure was measured as 0.024 MPa at 10% ClO2 and 0.641 MPa at 90% ClO2.The induction time (the time from the moment of sparking to explosion) at 10% ClO2 was 2195 ms,but at 90% ClO2 the induction time was just 8 ms.The explosion reaction mechanism of ClO2 is of a degenerate chain-branching type involving the formation of a stable intermediate (Cl2O3),from which the chain branching occurs.
Trans-cis photoisomerization of azobenzene by n→π* excitation:A semiclassical dynamics study
Shuai Yuan , Wei Feng Wu , Yusheng Dou , Jian She Zhao
2008, 19(11): 1379-1382  doi: 10.1016/j.cclet.2008.07.007
[Abstract](156) [FullText HTML] [PDF 257KB](0)
Abstract:
A realistic dynamics simulation study is reported for the trans-cis photoisomerization of azobenzene triggered by the n→π* excitation and the results show that the formation of cis isomer follows the rotational motion around the N=N bond.The simulation find that the CNN bond angle bending vibrations also play a significant role in the vibronic coupling between the HOMO and LUMO,which essentially leads a nonadiabatic transition of the molecule to the electronic ground state.
A density functional theoretical studies on the structures and aromaticities of (CH)n(BCO)6-n (n=0-6)
Zheng Guo Huang , Li Zhou , En Cui Yang
2008, 19(11): 1383-1386  doi: 10.1016/j.cclet.2008.07.025
[Abstract](151) [FullText HTML] [PDF 213KB](0)
Abstract:
Density functional theoretical calculations have been made on the electronic structure of (CH)n(BCO)6-n(n=0-6) at B3LYP/6-311+G(d) level.The nuclear-independent chemical shifts (NICS) values calculated using the gauge-including atomic orbitals (GIAO) method were used to assess on the aromaticities of these molecules.The results shows that (CH)n(BCO)6-n(n=0-6)species are aromatic.
Study on the active sites of Cu-ZSM-5 in trichloroethylene catalytic combustion with air
Cheng Hua Xu , Chuan Qi Liu , Yan Zhong , Xiu Zhou Yang , Jian Ying Liu , Ying Chun Yang , Zhi Xiang Ye
2008, 19(11): 1387-1390  doi: 10.1016/j.cclet.2008.07.010
[Abstract](171) [FullText HTML] [PDF 393KB](0)
Abstract:
The catalytic activity of Cu-ZSM-5 in trichloroethylene (TCE) combustion increases with the increasing skeletal Cu amount and however decreases with the increase of surface amorphous CuO,which is detected by infrared spectroscopy (IR) and diffuse reflectance ultraviolet-visible spectroscopy (DRS-UV-vis),therefore the skeletal Cu species are concluded to be the active sites for the TCE combustion.
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