2008 Volume 19 Issue 5

Efficient synthesis of 4(3H)-quinazolinones using a soluble polymeric support
Chang Xie , Hong Xia Li , Ming Guo Liu , Ming Wu Ding
2008, 19(5): 505-508  doi: 10.1016/j.cclet.2008.03.013
[Abstract](144) [FullText HTML] [PDF 245KB](0)
Abstract:
4(3H)-Quinazolinones have been synthesized from poly (ethylene glycol) (PEG) supported aza-Wittig reaction. 2-Dialkylamino-4(3H)-quinazolinones 6 were synthesized efficiently by reaction of secondary amine with PEG-supported carbodiimides 4, whichwere obtained from aza-Wittig reaction of PEG-supported iminophosphoranes 3 with isocyanates.
Synthesis, DNA binding and topoisomerase inhibition of mononaphthalimide homospermidine derivatives
Zhi Yong Tian , Hong Xia Ma , Song Qiang Xie , Xue Wang , Jin Zhao , Chao Jie Wang , Wen Yuan Gao
2008, 19(5): 509-512  doi: 10.1016/j.cclet.2008.03.006
[Abstract](157) [FullText HTML] [PDF 527KB](0)
Abstract:
Two novel mononaphthalimide homospermidine derivatives (2a, 2b) with three or four methylene unit as linkages weresynthesized and evaluated for cytotoxicity against human leukemia K562, murine melanoma B 16 and Chinese hamster ovary CHOcell lines. The presence of homospermidine motif could greatly elevate the potency of 1,8-naphthalimide. Conjugate 2b with longerspacer exhibited higher in vitro cytotoxicity than 2a. The DNA binding experiments indicated that conjugates 2b could bind toherring sperm DNA. The topoisomerase Ⅱ poison trials revealed that 2b could inhibit the activity of top. Ⅱ.
Synthesis of novel biscrown ethers with rigid cis/trans ethylene bridge
Jian Quan Fan , La Sheng Jiang , Min Zhang , Na Wei , Ya Hui Feng , Shu Juan Han , Hui Wang
2008, 19(5): 513-517  doi: 10.1016/j.cclet.2008.03.002
[Abstract](149) [FullText HTML] [PDF 753KB](0)
Abstract:
Two novel biscrown ethers with rigid cisltrans ethylene linker were synthesized v/a Wittig reaction in high yield (about 80%).Their pure cis/trans-isomers were obtained by column chromatography separation. And their structure/configuration was confirmedby 1H NMR, 13C NMR, ESI mass spectrum, elemental analysis and UV-vis spectra.
A rapid and efficient synthesis of indoloquinolinone and its analogues under microwave irradiation
Yu Jing Lu , Ning Sun , Zhi Shu Huang , Lian Quan Gu
2008, 19(5): 518-520  doi: 10.1016/j.cclet.2008.03.028
[Abstract](144) [FullText HTML] [PDF 206KB](0)
Abstract:
A rapid and efficient method was established for the synthesis of indoloquinolinone and its analogues using acid-promotedcyclization in the present of PPA. All the reactions were completed in good yields in 10min under microwave irradiation.
Synthesis of azobenzene-containing liquid crystalline gelator for use in liquid crystal gels
Guang Wang , Xiao Liang Zhao , Yue Zhao
2008, 19(5): 521-524  doi: 10.1016/j.cclet.2008.01.043
[Abstract](152) [FullText HTML] [PDF 690KB](0)
Abstract:
A liquid crystalline gelator containing the azobenzene chromophore was synthesized for the first time; it was used to form self-assembled network in nematic liquid crystals resulting in liquid crystal gels with distinct features.
A rapid synthesis of isoxazolo[5,4-d]pyrimidin-4(5H)-ones under microwave irradiation with solid acid catalysis in solvent-free conditions
A. Davoodnia , M. Roshani , S.H. Malaeke , M. Bakavoli
2008, 19(5): 525-528  doi: 10.1016/j.cclet.2008.01.037
[Abstract](148) [FullText HTML] [PDF 219KB](0)
Abstract:
A rapid and efficient method for the synthesis of isoxazolo[5,4-d]pyrimidin-4(5H)-ones has been developed throughcyclocondensation of 5-aminoisoxazole-4-carboxamides with orthoesters under conventional heating and solvent-free microwaveirradiation with solid acid catalysis. In comparison, the reactions are faster and the yields are higher under microwave irradiation.
Photopromoted carbonylation of 1-bromo-6-chlorohexane under ambient conditions
Yao Yun Hu , Jing Mei Yin , Da Bin Gao , Ying Ping Jia , Guang Yun Zhou , Ying Na Cui , Shen Min Li
2008, 19(5): 529-532  doi: 10.1016/j.cclet.2008.03.020
[Abstract](148) [FullText HTML] [PDF 240KB](0)
Abstract:
Photopromoted carbonylation of 1-bromo-6-chlorohexane with CO catalyzed by CuBr2 and CdI2 has been carried out underambient conditions. The results indicate that the carbonylation proceeds with the major product of chlorocsterCICH2(CH2)5COOCH3 under catalysis of CuBr2. Furthermore, the activity of the carbonylation can be improved by additionof basic additives (NaOAc, Na3PO4 or (n-C4H9)3N). Among these additives, (n-C4H9)3N is the most efficient in terms of the yield ofClCH2(CH2)5COOCH3. However, the methoxycarbonyl substituting chlorine product of BrCH2(CH2)5COOCH3 is not obtained inthe presence of CdI2. This is quite different from the carbonylation of monochloroalkane.
Synthesis of aza-naphthindolizinedione derivatives
De Qing Shen , Yu Cheng , Lin Kun An , Xian Zhang Bu , Zhi Shu Huang , Lian Quan Gu
2008, 19(5): 533-536  doi: 10.1016/j.cclet.2008.03.034
[Abstract](149) [FullText HTML] [PDF 266KB](0)
Abstract:
A series of aza-naphthindolizinedione derivatives, such as indolizinoquinolinedione derivatives, indolizinophthalazinedionederivatives and indolizinoquinoxalinedione derivatives were designed and synthesized. The synthetic pathway was also proposed.
Facile and efficient synthesis of 2-substituted-N1-carbethoxy-2, 3-dihydro-4(1H)-quinazolinones in fluorous solvent
Bai Ling Xu , Jin Ping Chen , De Cai Fu
2008, 19(5): 537-540  doi: 10.1016/j.cclet.2008.03.022
[Abstract](148) [FullText HTML] [PDF 199KB](0)
Abstract:
A facile, efficient and novel approach to access 2-substituted-N1-carbethoxy-2,3-dihydro-4(1H)-quinazolinones was developedby condensation of substituted N-carbethoxyanthranilamide with alkyl, aromatic or heteroaromatic aldehydes in the refluxing 2,2,2-trifluoroethanol or hexafluoroisopropanol using p-toluenesulfonic acid as catalyst.
New synthetic way to prepare 2-aryl-8-(piperidin-4-yl)-5, 7-dimethoxy-4H-chromen-4-one as key intermediate for CDK inhibitor
Yan Ling Li , Hao Fang , Wen Fang Xu , Bing He Wang
2008, 19(5): 541-543  doi: 10.1016/j.cclet.2008.03.025
[Abstract](145) [FullText HTML] [PDF 220KB](0)
Abstract:
As an important intermediate to study cyclin-dependent kinase (CDK) inhibitors, 2-aryl-8-(piperidin-4-yl)-5,7-dimethoxy-4H-chromen-4-one derivatives were prepared using β-diketone route with low yield. In our study, chalcone route has been investigatedand the result suggested that the benzaldehydes substituted with electron-donating group give much better yield than β-diketoneroute. This new method will be an efficient way to start further research on new anticancer flavonoids.
Steroidal alkaloids from the bulbs of Fritillaria monatha
Hong Ning Liu , Fei Li , Yong Ming Luo , Wei Feng Zhu
2008, 19(5): 544-546  doi: 10.1016/j.cclet.2008.03.008
[Abstract](149) [FullText HTML] [PDF 220KB](0)
Abstract:
Two new Steroidal alkaloids, named pengbeisine A and pengbeisine B, were isolated from the fresh bulbs of Fritillaria monatha Migo. along with a known alkaloid. The structures were characterized as 22,26-imino-17, 23-oxido-5α-jerv-6-oxo-2α,3β-diol and22, 26-imino-17, 23-oxido-5α-jerv-6-oxo-2β,3α-diol on the basis of spectroscopic methods.
A new diarylheptanoid from the bark of Myrica rubra
Ding Yong Wang , En Gui Liu , Yu Jing Feng
2008, 19(5): 547-549  doi: 10.1016/j.cclet.2008.03.004
[Abstract](145) [FullText HTML] [PDF 258KB](0)
Abstract:
A new diarylheptanoid, 3,5-dimethoxyl-17-hydroxyl-4,11,19-triketo-[7,0]meta-cyclophane, named as rubanone 1, was isolatedfrom the bark of Myrica rubra along with four known compounds 2-5. Their structures were elucidated by various spectroscopicmethods including 2D-NMR techniques or comparison with authentic samples.
A new lignan derivative from the root of Ilex pubescens
Yu Bo Zhou , Jin Hui Wang , Xiang Mei Li , Xian Li
2008, 19(5): 550-552  doi: 10.1016/j.cclet.2008.03.017
[Abstract](153) [FullText HTML] [PDF 221KB](0)
Abstract:
One new compound, ilexlignan A (1), was isolated from the root of llex pubescens. Its structure was elucidated by thecombination of one-and two-dimensional NMR analysis, mass spectrometry, CD spectrum measurement and chemical evidence.
Synthesis of phosphorus-containing polyoxamacrocycles with one to two reactive thiophosphoryl chloride groups
Xiao Mei Zhang , Dao Quan Wang , Wan Yi Chen
2008, 19(5): 553-555  doi: 10.1016/j.cclet.2008.03.031
[Abstract](148) [FullText HTML] [PDF 218KB](0)
Abstract:
Novel phosphorus-containing polyoxamacrocycles with one to two reactive thiophosphoryl chloride groups 5, 6, 7, 8 weresynthesized from bishydroxyl compounds 1, 2, 3, 4 and thiophosphoryl chloride respectively. Their structures were confirmed by 1HNMR, 13C NMR, 31p NMR and elemental analysis.
Anthranilic acid derivatives from Inula japonica
Jiang Jiang Qin , Hui Zi Jin , Jian Jun Fu , Xiao Jia Hu , Yan Zhu , Yun Heng Shen , Shi Kai Yan , Wei Dong Zhang
2008, 19(5): 556-558  doi: 10.1016/j.cclet.2008.03.026
[Abstract](154) [FullText HTML] [PDF 217KB](0)
Abstract:
Three new anthranilic acid derivatives, N-heneicosanoylanthranilic acid (1b), N-tricosanoylanthranilic acid (1d), N-tetra-cosanoylanthranilic acid (1e), and two known N-arachidylanthranilic acid (1a) and N-docosanoylanthranilic acid (1c) were isolatedfrom the aerial parts of Inula japonica Thunb. Their structures were established by spectroscopic and chemical methods.
A new bibenzyl derivative from Pleione bulbocodioides
Xin Qiao Liu , Qiao Yu Yuan , Yuan Qiang Guo
2008, 19(5): 559-561  doi: 10.1016/j.cclet.2008.03.023
[Abstract](152) [FullText HTML] [PDF 201KB](0)
Abstract:
A new bibenzyl derivative 1, named 2-(4"-hydrixybenzyl)-3-(3'-hydroxyphenethyl)-5-methoxy-cyclohexa-2,5-diene-1,4-dione, and two known stilbenoids (2,3) were isolated from the tubers of Pleione bulbocodioides (Franch.) Rolfe. Their structureswere elucidated by spectroscopic methods.
Eremophilane sesquiterenes from the marine fungus Penicillium sp. BL27-2
Yong Fu Huang , Li Qiao , A.Li Lv , Yue Hu Pei , Li Tian
2008, 19(5): 562-564  doi: 10.1016/j.cclet.2008.03.018
[Abstract](157) [FullText HTML] [PDF 250KB](0)
Abstract:
Six eremophilane sesquiterpenes were obtained from a marine fungus Penicillium sp. BL27-2. Their structures were elucidatedas 3-acetyl-9, 7 (11)-dien-7ot-hydroxy-8-oxoeremophilane (1), 3-acetyl-13-deoxyphomenone (2), Sporogen-AO 1 (3), 7-hydro-xypetasol (4), 8α-hydroxy-13-deo-xyphomenone (5) and 6-dehydropetasol (6) based on detailed NMR analysis. 1 was a newcompound and 2 was obtained as a new natural compound. These compounds were assayed for their cytotoxic activity on P388,A549, HL60, BEL7402 and K562 cell lines by the MTT method. The assay results suggested the epoxide tings in eremophilanemolecules were essential for their activity, and acetylation could enhance their activity.
Indirect determination of cefradine with n-propyl alcohol-ammonium sulfate-water system by extraction-flotation of cuprous thiocyanate
Ling Li Wu , Wei Zhao , Quan Min Li
2008, 19(5): 565-568  doi: 10.1016/j.cclet.2008.03.033
[Abstract](153) [FullText HTML] [PDF 217KB](0)
Abstract:
A new method was developed for the determination of cefradine by extraction-flotation of CuSCN. The experiment indicatedthat in the presence of 0.20 mol/L NaOH the degradation of cefradine took place in water bath at 100℃. The thiol group (-SH) ofthe degradation product could reduce Cu(Ⅱ) to Cu(Ⅰ) for the formation of the emulsion CuSCN in the presence of NH4SCN at pH4.0. By determining the residual amount of Cu(Ⅱ) in the solution and calculating the flotation yield of Cu(Ⅱ), the indirectdetermination of cefradine can be obtained. This method has been applied to determine cefradine in capsules, human serum andurine samples, respectively.
Rapid determination of Cl- by light-absorption ratio variation approach using Cl--eosin Y-Ag+ adsorptive precipitation
Jing Bai , Hong Yan Wang , Hong Wen Gao
2008, 19(5): 569-572  doi: 10.1016/j.cclet.2008.02.004
[Abstract](153) [FullText HTML] [PDF 285KB](0)
Abstract:
The adsorptive precipitation between eosin Y (EY) and AgCl colloids at pH 3.73 caused the sensitive color change of thesolution. The reaction mechanism between EY and AgCl was analyzed and this reaction was used for determination of Cl-in tracelevel by the light-absorption radio variation approach.
Reactivity of ambient volatile organic compounds (VOCs) in summer of 2004 in Beijing
Shan Huang , Min Shao , Sihua Lu , Ying Liu
2008, 19(5): 573-576  doi: 10.1016/j.cclet.2008.03.029
[Abstract](156) [FullText HTML] [PDF 792KB](0)
Abstract:
Ambient volatile organic compounds (VOCs) were sampled at six sites in Beijing in the summer of 2004 and analyzed byGCMS. The chemical reactivities of 73 quantified VOCs species were evaluated by OH loss rates (LOH) and ozone formationpotentials (OFPs). Top 15 reactive species, mainly alkenes and aromatics, were identified by these two methods, and accounted formore than 70% of total reactivity of VOCs. In urban areas, isoprene was the most reactive species in term of OH loss rate,contributing 11.4% to the LOH of VOCs. While toluene, accounting for 9.4% of OFPs, appeared to have a long-time role in thephotochemical processes. Tongzhou site is obviously influenced by local chemical industry, but the other five sites showed typicalurban features influenced mainly by vehicular emissions.
Electrochemical study of the effect of functionalized nickel nanoparticles on cellular uptake of leukemia cancer cells in vitro
Da Dong Guo , Chun Hui Wu , Xue Mei Wang , Bao An Chen
2008, 19(5): 577-580  doi: 10.1016/j.cclet.2008.01.038
[Abstract](166) [FullText HTML] [PDF 748KB](0)
Abstract:
In this study, we have fabricated the functionalized nickel nanoparticles and investigated their effects on cellular uptake ofquercetin in leukemia K562 cancer cells by using electrochemical assay. The results indicate that nickel nanoparticles couldefficiently enhance the quercetin uptake and increase the intracellular accumulation in cancer cells, implying the great potential offunctionalized nickel nanoparticles in target cancer therapy.
The electrochemical behavior of N-n-undecyl-N´-(sodium-p-amino-benzenesulfonate) thiourea and its interaction with bovine serum albumin
Hong Xia Luo , Yang Du , Zhi Xin Guo
2008, 19(5): 581-584  doi: 10.1016/j.cclet.2008.03.024
[Abstract](143) [FullText HTML] [PDF 296KB](0)
Abstract:
In pH 5.5 phosphate buffer solution, N-n-undecyl-N'-(sodium-p-amino-benzenesulfonate) thiourea (UPT) produced a pair ofredox peaks on the bare glassy carbon electrode. At the multi-walled carbon nanotube (MWNT) modified electrode, theelectrochemical behavior of UPT enhanced greatly. In the presence of bovine serum albumin (BSA), the peak currents ofUPT decreased linearly due to the formation of a super-molecular complex. This method was successfully applied to thedetermination of BSA in a bovine serum sample.
Preparation of cauliflower-like bismuth sulfide and itsapplication in electrochemical sensor
Qing Xiang Wang , Feng Gao , Shun Xing Li , Wen Weng , Zheng Shui Hu
2008, 19(5): 585-588  doi: 10.1016/j.cclet.2008.03.001
[Abstract](151) [FullText HTML] [PDF 930KB](0)
Abstract:
A solvothermal process was developed for the preparation of cauliflower-like Bi2S3 from N,N-dimethylformamide (DMF)solution of bismuth nitrate [Bi(NO3)3·5H2O] and thioacetamide (TAA) with 2-undecyl-1-dithioureido-ethyl-imidazoline (SUDEI)as the morphology-controlling agent· The obtained Bi2S3 products were characterized by transmission electron microscopy (TEM),scanning electron microscopy (SEM), and X-ray diffraction (XRD), etc· The sensing properties of Bi2S3 with differentmorphologies were evaluated by the electrochemical analysis of dopamine (DA) and ascorbic acid (AA) coexisting solution·The results showed that cauliflower-like Bi2S3 showed a better resolving ability than rod-like Bi2S3 for the simultaneousdetermination of DA and AA·
Electrochemical sensing of DNA immobilization and hybridization based on carbon nanotubes/nano zinc oxide/chitosan composite film
Wei Zhang , Tao Yang , Da Ming Huang , Kui Jiao
2008, 19(5): 589-591  doi: 10.1016/j.cclet.2008.03.012
[Abstract](125) [FullText HTML] [PDF 1100KB](0)
Abstract:
A novel electrochemical DNA biosensor based on zinc oxide (ZnO) nanoparticles and multi-walled carbon nanotubes (MWNTs)for DNA immobilization and enhanced hybridization detection is presented. The MWNTs/nano ZnO/chitosan composite filmmodified glassy carbon electrode (MWNTs/ZnO/CHIT/GCE) was fabricated and DNA probes were immobilized on the electrodesurface. The hybridization events were monitored by differential pulse voltammetry (DPV) using methylene blue (MB) as anindicator. The sensor can effectively discriminate different DNA sequences related to PAT gene in the.transgenic corn, with adetection limit of 2.8×10-12 mol/L of target sequence.
Study of enzyme biosensor based on carbon nanotubes modified electrode for detection of pesticides residue
Shu Ping Zhang , Lian Gang Shan , Zhen Ran Tian , Yi Zheng , Li Yi Shi , Deng Song Zhang
2008, 19(5): 592-594  doi: 10.1016/j.cclet.2008.03.014
[Abstract](127) [FullText HTML] [PDF 1001KB](0)
Abstract:
he paper describes a controllable layer-by-layer (LBL) self-assembly modification technique of multi-walled carbon nanotubes(MWNTs) and poly(diallyldimethylammonium chloride) (PDDA) towards glassy carbon electrode (GCE), Acetylcholinesterase(ACHE) was immobilized directly to the modified GCE by LBL self-assembly method, the activity value of AChE was detected by using i-t technique based on the modified Ellman method. Then the composition of carbaryl were detected by the enzyme electrode with 0.01U activity value and the detection limit of carbaryl is 10-12 g L-1 so the enzyme biosensor showed good properties for pesticides residue detection.
A novel protein refolding method integrating ion exchange chromatography with artificial molecular chaperone
Qin Ming Zhang , Chao Zhan Wang , Jiang Feng Liu , Li Li Wang
2008, 19(5): 595-598  doi: 10.1016/j.cclet.2008.03.030
[Abstract](125) [FullText HTML] [PDF 184KB](0)
Abstract:
Artificial molecular chaperone (AMC) and ion exchange chromatography (IEC) were integrated, thus a new refolding method,artificial molecular chaperone-ion exchange chromatography (AMC-IEC) was developed. Compared with AMC and IEC, theactivity recovery of lysozyme obtained by AMC-IEC was much higher in the investigated range of initial protein concentrations,and the results show that AMC-IEC is very efficient for protein refolding at high concentrations. When the initial concentration oflysozyme is 180 mg/mL, its activity recovery obtained by AMC-IEC is still as high as 76.6%, while the activity recoveries obtainedby AMC and IEC are 45.6% and 42.4%, respectively.
Fabrication and gas sensing property of honeycomb-like ZnO
Chao Li , Zhi Shuo Yu , Shao Ming Fang , Huan Xin Wang , Yang Hai Gui , Jia Qiang Xu , Rong Feng Chen
2008, 19(5): 599-603  doi: 10.1016/j.cclet.2008.03.032
[Abstract](131) [FullText HTML] [PDF 1029KB](0)
Abstract:
We report the structural characterization and proposed formation mechanism of honeycomb-like ZnO conglomerationsfabricated by direct precipitation method. X-ray diffraction (XRD), energy-disperse X-ray spectrometry (EDS), scanning electronmicroscopy (SEM) showed that the as-prepared ZnO calcined at 700℃ were micron sphere particles with honeycomb-likestructure. In the UV-vis absorbing spectrum, it was observed that there is a new additional absorption band at 260 nm, and it wasspeculated that the absorption may be caused by defects on the surface and interface of honeycomb-like ZnO. The as-productsshowed high sensitivity and short response time to sulfured hydrogen gas. These results demonstrate that honeycomb-like ZnOconglomerations are very promising materials for fabricating H2S gas sensors.
Formation of a three-dimensional bispyridyl based metal–organic architecture containing unique Ag···Ag (d10–d10) interactions
Xiao Ling Guo , Yun Yin Niu , Qing Li Wang , Ben Lai Wu , Hong Yun Zhang , Hong Wei Hou , Yi Han , Ling Fang Wang
2008, 19(5): 604-606  doi: 10.1016/j.cclet.2008.01.020
[Abstract](121) [FullText HTML] [PDF 708KB](0)
Abstract:
A novel co-ordination polymer based on IB metal thiocyanates, [Ag2(NCS)2(4,4'-bipy)]n (1)(4,4'-bipy=4,4'-bispyridine), hasbeen synthesized by the pre-assembly method and characterized by X-ray crystallography. The complex exists as a three-dimensional network consisting of (AgSCN)n undulating layers linked by 4,4'-bipy bridges.
Photoinduced hydrogen evolution in an artificial system containing photosystem I,hydrogenase,methyl viologen and mercaptoacetic acid
Dong Jin Qian , Ai Rong Liu , Chikashi Nakamura , Stephan Olav Wenk , Jun Miyake
2008, 19(5): 607-610  doi: 10.1016/j.cclet.2008.03.015
[Abstract](143) [FullText HTML] [PDF 272KB](0)
Abstract:
Hydrogen evolution was detected in an artificial system composed of light-harvesting unit of purified photosystem Ⅰ, catalyst ofhydrogenase, methyl viologen and electron donor under radiation. Absorption spectral features confirmed that electron transferfrom electron donors to proton was via a photoinduced reductive process of methyl viologen.
Facile synthesis and characterization of novel pseudo-hypercrosslinked resin
Si Guo Yuan , Shao Hui Zhang , Wei Hua Zou , Yong Hao Zhou , Xiao Hui Zhou
2008, 19(5): 611-614  doi: 10.1016/j.cclet.2008.02.003
[Abstract](118) [FullText HTML] [PDF 928KB](0)
Abstract:
A kind of pseudo-hypercrosslinked polymer resin was firstly synthesized via a continuous Friedel--Crafts alkylation poly-merization of benzene, diphenyl and their dichloromethyl derivatives. And the micromorphology and adsorption properties of theseresins were investigated. The results demonstrated that the novel resins have high-specific surface area (581.26-974.88 m2/g), high-pore volume (0.56-1.65 mL/g), small average porous radius (1.93-3.67 nm) and excellent adsorption properties for small non-polarorganic molecules.
The study on preparing anti-radiation material by reverse microemulsion method
Ping Ping Jiang , Xue Min Lin , Jian Bo Chen
2008, 19(5): 615-618  doi: 10.1016/j.cclet.2008.03.009
[Abstract](126) [FullText HTML] [PDF 269KB](0)
Abstract:
A new way to prepare PMMA contain lead salt was presented. This work firstly prepares the material by microemulsionpolymerization. The ability of anti-radiation, transmittance ratio and glass transition temperature (Tg) of the material wascharacterized. The anti-radiation ability is enhanced with the increasing of lead salt content and the thickness of the material. Thetransmittance ratio decreased with the content of the lead salt. The glass transition temperature of the material is increased with thelead salt content of the organic glass.
Pharmacophore model for neonicotinoid insecticides
Jian Li , Xiu Lian Ju , Feng Chao Jiang
2008, 19(5): 619-622  doi: 10.1016/j.cclet.2008.03.011
[Abstract](137) [FullText HTML] [PDF 371KB](0)
Abstract:
An effective prediction pharmacophore model (RMS=0.634, Correl=0.893, Weight=1.463, Config=11.940) was success-fully obtained by 3D-QSAR based on a series of nAChR (nicotinic acetylcholine receptors) agonists, which consists of a hydrogen-bonding acceptor, a hydrogen-bond donor, a hydrophobic aliphatic and a hydrophobic aromatic centre. This pharmacophore modelmay provide theoretical basis for designation and development of higher active insectici
Effect of water droplet in solvent sublation
Peng Yu B , Hui Ru Dong , Nan Nan Wang
2008, 19(5): 623-626  doi: 10.1016/j.cclet.2008.03.010
[Abstract](131) [FullText HTML] [PDF 303KB](0)
Abstract:
Aqueous phase layer around bubble and water droplet are two additional processes in solvent sublation. In the dynamic processof mass transfer, they are always neglected, but they are very important in the investigation of thermodynamic equilibrium. In thispaper, the effect of water droplet in solvent sublation was discussed in detail, and the previous mathematical model of solventsubaltion was improved. Matlab 6.5 was used to simulate the process of water droplets, and the comparison between the previoushypothesis and the improvement in this paper showed the superiority, especially in the investigation of thermodynamic equilibrium.Moreover, the separation and concentration of the complex compound dithizone-Co(Ⅱ) from aqueous phase to n-octanol by solventsublation also proved the improved mathematical model was reasonable.
An ab initio potential energy surface and vibrational energy levels of HXeBr
Zheng Guo Huan , En Cui Yang , Dai Qian Xie
2008, 19(5): 627-630  doi: 10.1016/j.cclet.2008.03.019
[Abstract](130) [FullText HTML] [PDF 244KB](1)
Abstract:
A three-dimensional global potential energy surface for the electronic ground state of HXeBr molecule is constructed from morethan 4200 ab initio points. These points are generated using an internally contracted multi-reference configuration interactionmethod with the Davidson correction (icMRCI+Q) and large basis sets. The stabilities and dissociation barriers are identified fromthe potential energy surfaces. The three-body dissociation channel is found to be the dominate dissociation channel for HXeBr.Based on the obtained potentials, low-lying vibrational energy levels of HXeBr calculated using the Lanczos algorithm is found tobe in good agreement with the available experimental band origins.
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