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Archive By Volume
Acta Chimica Sinica 2007 Vol.65
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Original Articles
Rapid Functionalization of Carbon Nanotube and Its Electrocatalysis
DU Pan; SHI Yan-Mao; WU Ping; ZHOU Yao-Ming; CAI Chen-Xin*
Acta Chimica Sinica 2007, 65 (1): 1-9.
Published: 14 January 2007
Abstract
(
2173
)
PDF
(757KB)(
1077
)
Knowledge map
It was reported that carbon nanotube (CNT) was functionalized with the electroactive Nile Blue (NB), which was a phenoxazine dye, by a method of adsorption to form an NB-CNT nanocomposite. The spectroscopic results showed that NB can be rapidly and effectively adsorbed on the surface of CNT with high stability without changing the native structure of NB and the structure properties of CNT. Moreover, it was shown that the dispersion ability of CNT in aqueous solution had a significant improvement after CNT was functionalized with NB even at a level of high concentration, for example 5 mg of NB-CNT per 1 mL of H
2
O. The NB-CNT/GC electrode was fabricated by modifying NB-CNT nanocomposite on the GC electrode surface and its electrochemical properties were investigated by cyclic voltammetry. The cyclic voltammetric results indicated that CNT could improve the electrochemical behavior of NB and greatly enhance its redox peak currents. While the NB-CNT/GC electrode exhibited a pair of well-defined and nearly symmetrical redox peaks with the formal potential of (-0.422±0.002) V (vs. SCE, 0.1 mol/L PBS, pH 7.0), which was almost independent of the scan rates, for electrochemical reaction of NB monomer, the redox peak potential of NB polymer located at about -0.191 V. The experimental results also demonstrated that NB and CNT could synergistically catalyze the electrochemical oxidation of NADH (
β
-nicotinamide adenine dinucleotide, reduced form) and NB-CNT exhibited a high performance with lowering the overpotential by more than 560 mV. The NB-CNT/GC electrode could effectively sense the concentration of NADH, which was produced during the process of oxidation of substrate (for example ethanol) catalyzed by dehydrogenase (for example alcohol dehydrogenase). The presented method for functionalization of CNT had several advantages, such as rapid and facile CNT functionalization, easy electrode fabrication, high electrocatalytic activity,
etc
., and could be used for fabrication of electrochemical biosensor based on dehydrogenase.
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Original Articles
Investigations on the Electrode Process and Kinetics of Li-ion Extraction/Insertion in Li
3
V
2
(PO
4
)
3
(I)
LIU Su-Qin; LI Shi-Cai; HUANG Ke-Long*
Acta Chimica Sinica 2007, 65 (1): 10-16.
Published: 14 January 2007
Abstract
(
2195
)
PDF
(424KB)(
1592
)
Knowledge map
The compound of monoclinic Li
3
V
2
(PO
4
)
3
, synthesized by sol-gel method, was certified by X-ray diffraction and its electrochemical performance was investigated by charge/discharge method, cyclic voltammetry and differential capacity data (Electrochemical Voltage Spectroscopy, EVS). Electrochemical impedance spectroscopy (EIS) using a two-electrode system in a frequency range from 1 MHz to 0.01 Hz was conducted on a Li
3
V
2
(PO
4
)
3
electrode, and two different equivalent circuits was proposed for fitting the experimental results, consequently to evaluate the kinetics of Li-ion extraction and insertion at Li
3
V
2
(PO
4
)
3
and its evolution of surface/interface.
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Original Articles
Study on Crystal Structure and Interaction with Biologic Molecule of Bis[tri(hydroxymethyl)methylglycine] Ni(II) Complex
GAO En-Jun*
,1,2
; CHENG Mao-Sheng
2
; LI Hao-Yang; DING Li-Na; SUN Ya-Guang
Acta Chimica Sinica 2007, 65 (1): 17-20.
Published: 14 January 2007
Abstract
(
1888
)
PDF
(305KB)(
1270
)
Knowledge map
A single crystal of complex [Ni(tricine)
2
]•6H
2
O was synthesized, where tricine is tri(hydroxy- methyl)methylglycine. The crystal belongs to monoclinic system,
P
2(1)/
n
space group. One nitrogen atom and two oxygen atoms of the tri(hydroxymethyl)methylglycine coordinate to nickel(II). The Ni(II) presents an octahedral geometry. Two dimensional structure of the complex is formed by intermolecular hydrogen bonds. The interaction of complex with fish sperm, ATP and ade is studied by UV spectrum, and their interacion mechanism is also primary analyzed.
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Original Articles
Studies on the Synthesis and Molecular Dynamics Simulation of Dendrimers Containing Amino Acids and Peptides
HE Gu; GUO Li*
,1
; MA Li-Fang
2
; WANG Qian-Qian; HE Ze-Chao
2
Acta Chimica Sinica 2007, 65 (1): 21-26.
Published: 14 January 2007
Abstract
(
1770
)
PDF
(592KB)(
925
)
Knowledge map
A series of poly(ether-amide) dendrimers functionalized by amino acids and peptides were synthesized, and their structures were confirmed by NMR and ESI-MS. The molecular dynamics simulation of peptide dendrimers in solution was performed. The main results demonstrate that the prior conformations of molecules are atom-number dependent, with more atom-number more spherical. C
α
atom radial distribution indicated that with larger peripheral groups more back-folding of the molecules occurs.
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Cited: CSCD(
2
)
Original Articles
Salt-Induced Spontaneous Vesicle Formation from Aqueous Mixture of Anionic/Nonionic Surfactants
ZHAI Li-Min*
,1
; WANG Hui
2
; XU Jian
3
; ZHANG Long-Jun; ZHAO Mei
Acta Chimica Sinica 2007, 65 (1): 27-31.
Published: 14 January 2007
Abstract
(
2232
)
PDF
(455KB)(
901
)
Knowledge map
Without salt, only mixing micelles exist in aqueous mixture of anionic surfactant sodium dodecyl benzenesulfonate (SDBS) and nonionic surfactant octylphenoxypolyethoxyethanol (TX-100). However, the addition of salt induces the spontaneous formation of vesicle, which makes the formation of vesicle much easier and simpler. The mechanism of the formation may be attributed to the compression of salt on the electric bilayer of the surfactant head groups, which reduces their area and increases the packing parameter
P
of the surfactant under the participation of TX-100, resulting in the formation of larger aggregates. The vesicle region is presented in a pseudo-ternary diagram of SDBS/TX-100/brine by visual observation and surface tension measurement, which exhibits a strip-shape. The existence of vesicles is demonstrated by TEM image using negative-staining method. The variations of vesicle size with the salinity and the surfactant concentration are determined using dynamic light scattering method. It is found that the vesicle size is independent on the surfactant concentration, but subject to the salinity of the solution.
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Cited: Baidu(
10
) CSCD(
2
)
Original Articles
The Synthesis of the Optically Active Ethyl Polyhydroxy Heptanoate
WANG Jin-Xin
1,2
; HE Ling; YOU Qi-Dong*
,1
; LI Ying*
,2
Acta Chimica Sinica 2007, 65 (1): 32-36.
Published: 14 January 2007
Abstract
(
1858
)
PDF
(340KB)(
893
)
Knowledge map
The first synthesis of ethyl (+)-(2
R
,3
S
,4
S
,5
S
)-4,5-epoxy-2,3-dihydroxy-6-methyl heptanoate (
5
)
and ethyl (-)-(2
R
,3
S
,4
R
,5
S
)-2,3,4,5-tetrahydroxy-6-methyl
heptanoate (
11
) was achieved and the key steps involved the construction of chiral carbon centers by the asymmetric epoxidation and dihydroxylation. This efficiently concise strategy has better stereochemistry and is adapted to the synthesis of polyhydroxyl fatty acid analogues. The primary tests of compounds
5
and
11
showed better inhibitory activities against HL60 cell line.
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Original Articles
Design, Synthesis and
in vitro
Antifungal Activities of Non-azole Lead Compound Based on Lanosterol 14
α
-Demethylase of Fungi
ZHU Jü; LÜ Jia-Guo; ZHOU You-Jun*; LI Yao-Wu; CHEN Jun; ZHENG Can-Hui
Acta Chimica Sinica 2007, 65 (1): 37-42.
Published: 14 January 2007
Abstract
(
2137
)
PDF
(728KB)(
1017
)
Knowledge map
Non-azole lead molecules were designed by coupling structure-based de novo design based on the structure of lanosterol 14
α
-demethylase (CYP51). The chemical synthesis and the evaluation of
in vitro
antifungal activities of them were reported. The results exhibited that all of the lead compounds showed potent antifungal activities., especially compounds
5f
and
5g
, which had stronger or equal antifungal activities against 5 test fungi than that of fluconazole.
The studies presented here provided the antifungal lead compounds. Because the affinity of the lead molecules for CYP51 was mainly attributed to their nonbonding interaction with the apoprotein, which was different from the azole antifungal agents. The studies presented here afford the opportunity to develop novel antifungal agents that specifically interact with the residues in the active site and avoid the serious toxicity arising from coordination binding with the heme of mammalian P450s.
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Original Articles
Investigations of the Interaction between 3-Aminophenylboronic Acid and Bovine Serum Albumin Using Fluorimetry
WANG Hua-Fang; LI Wen-You; HE Xi-Wen*
,1
; CHEN Lang-Xing; ZHANG Yu-Kui*
,1,2
Acta Chimica Sinica 2007, 65 (1): 43-48.
Published: 14 January 2007
Abstract
(
2535
)
PDF
(355KB)(
1375
)
Knowledge map
In order to
understand the chemical mechanism and optimal conditions of the molecular imprinting, the interaction between 3-aminophenylboronic acid (APBA) and bovine serum albumin (BSA) was investigated using fluorescence quenching method with many factors, as the pH value, ionic strength and others, which maybe influence the interaction. The research results indicate that under appropriate ionic strength and pH 6.25, the fluorescence quenching shows that APBA strongly
bound with the tryptophan of BSA, and the complex was formed with a molar ratio of 2∶1. Their apparent binding constant is
K
A
=1.0×10
11
L
2
•mol
-2
, so their chemical bonds between donor BSA and acceptor
APBA are relatively strong. According to the results, the interaction mechanism between APBA and BSA is predicted. During following research, it will be entirely possible to separate or enrich BSA composition, maybe it could improve imprinting and eluting efficiency greatly.
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Cited: CSCD(
4
)
Original Articles
Analysis of Two Trace Alkaloid Isomers in
Strychnos nux-vomical
by Electrospray Ionization Tandem Mass Spectrometry
YAN Jing
1,2
; LIU Zhi-Qiang*
,1
; ZHU Hai-Guang
2
; LIU Shu-Ying
Acta Chimica Sinica 2007, 65 (1): 49-52.
Published: 14 January 2007
Abstract
(
1863
)
PDF
(334KB)(
843
)
Knowledge map
According to their molecular mass and ESI-MS
n
data, the trace alkaloid isomers pseudostrychnine and strychnine
N
-oxide in extracts of the total alkaloids from
Strychnos nux-vomical
were qualitatively analyzed by electrospray ionization
tandem mass spectrometry (ESI-MS
n
) method after rough silica gel-column chromatographic separation. We also investigated the relationship between their fragmentation mechanism and structures of the two alkaloid isomers. A new method for quickly and highly sensitively analyzing the two alkaloid isomers was proposed.
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Cited: CSCD(
1
)
Original Articles
In Situ
Synthesis of Polyaniline-LiNi Ferrite Nanocomposite and Its Bonding Mechanism
JIANG Jing; LI Liang-Chao*
,1
; XU Feng; YAN Chong
2
Acta Chimica Sinica 2007, 65 (1): 53-58.
Published: 14 January 2007
Abstract
(
2081
)
PDF
(896KB)(
1041
)
Knowledge map
Polyaniline-LiNi
ferrite (LiNi
0.5
Fe
2
O
4
) nanocomposites were synthesized by
in situ
aqueous polymerization of aniline in the presence of ferrite. The structure, morphologies and magnetic properties of
samples were characterized by X-ray diffraction (XRD), infrared spectra (FTIR), Raman spectra, UV-Vis spectra, transmission electron microscope (TEM) and vibrating sample magnetometer (VSM) techniques. The results indicated that the nanocomposites under applied magnetic field exhibited the hysteresis loops of the ferrimagnetic nature at room temperature. The ferrite particles had the core effect on the polymerization of aniline. The bonding interaction existed between ferrite particles and polyaniline in the composites, and the bonding mechanism was investigated.
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Cited: CSCD(
15
)
Original Articles
Prediction of Equilibrium Hydrate Formation Conditions for Gas Mixtures Using the Statistical Associating Fluid Theory Equation of State
LI Xiao-Sen*
;
WU Hui-Jie
;
FENG Zi-Ping
;
TANG Liang-Guang
;
FAN Shuan-Shi
Acta Chimica Sinica 2007, 65 (1): 59-66.
Published: 14 January 2007
Abstract
(
2181
)
PDF
(366KB)(
1429
)
Knowledge map
The statistical associating fluid theory (SAFT) equation of state in conjunction with the statistical model of van der Waals and Platteeuw was employed to predict the formation equilibrium conditions of binary gas mixtures containing methane, ethane, propane, ethylene, propylene, H
2
S, CO
2
, N
2
and H
2
in the presence of aqueous solutions. The SAFT equation was used to describe the vapor and liquid phases. In calculation, the SAFT took into account hard sphere repulsion, hard chain formation, dispersion and association interactions. The van der Waals and Platteeuw model was applied to calculate the hydrate phase. The predictions were found to be in quite good agreement with the experimental data.
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Cited: CSCD(
5
)
Original Articles
Synthesis and UV Photosensitive Properties of TiO
2
-Amphiphilic Copolymer Composite Nanoparticles
SUN Yong; BI Yan-Ying*
,1
; SHI Feng
2
Acta Chimica Sinica 2007, 65 (1): 67-71.
Published: 14 January 2007
Abstract
(
1839
)
PDF
(936KB)(
1010
)
Knowledge map
The nanometer titanium dioxide particles were modified with the coupling agent vinyltriethoxysilane, dispersed in the medium of methanol applying the ultrasonic technique and encapsulated by
in situ
dispersion copolymerization with styrene (ST) and then with acrylamide or vinylpyrrolidone (VP). Titanium dioxide inorganic core and polymer shell composite nanoparticles were successfully prepared by two-step
in
situ
dispersion copolymerization. The spectra and micromorphology of two composite nanoparticles were characterized by Fourier transform IR spectroscopy, ultraviolet-visible spectroscopy measurement and transmission electron microscopy. The results show that with the photoactivation formed, which derived from coordination bond between core of TiO
2
nanoparticles and shell of amphiphilic copolymers that contain a lot of amide structure, the maximum absorption of both kind of composite nanoparticles are red shifted and the absorption spectra extent of two composite nanoparticles are broadened in the UV-Vis spectra figures, especially TiO
2
/(PST-co-PVP). This means their photosensitization and photoactivation are enhanced especially in visible light region. It is advantageous for photocatalytic properties of some wide bandgap semiconductor materials such as titanium dioxide nanoparticles, and indicates that the applied domain of this kind of material is enlarged.
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Reports
THz Time Domain Spectrum of
β
-Alanine
ZHENG Ying-Ying; LI Yuan-Bo; WANG Wei-Ning*
Acta Chimica Sinica 2007, 65 (1): 72-76.
Published: 14 January 2007
Abstract
(
1809
)
PDF
(454KB)(
856
)
Knowledge map
This paper reported the theoretical and experimental vibrational spectra of
β
-alanine in the frequency range from 0.2 to 2.4 THz (FIR) respectively. Under the room temperature and nitrogen conditions, the absorption peak was found at 2.11 THz and the average refractive index of the pure sample was 1.96 based on the terahertz time-domain spectroscopy (THz-TDS). The absorption spectrum of
β
-alanine from 0.1 to 10.0 THz was simulated by PM3 algorithm of semiempiricism. The agreement between the measured and theoretical results shows the torsional vibrational modes and the structural parameters of the sample.
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Reports
Theoretical Study of the Reaction of Excited State Ti
+
(3d
1
4s
2
) with
Propargyl Alcohol in Gas Phase
CHENG Wei-Xian
1,2
; LI Tao-Hong
3
; CAO Huai*
,1,2
Acta Chimica Sinica 2007, 65 (1): 77-80.
Published: 14 January 2007
Abstract
(
1884
)
PDF
(320KB)(
913
)
Knowledge map
The mechanism of the
excited state Ti
+
(3d
1
4s
2
) reacting with
propargyl alcohol (PPA) in gas phase has been studied using density functional theory (DFT). The geometries for the reactants, intermediates, products and transition states have been fully optimized at B3LYP/DZVP level. The single point energy of each stationary point was calculated at MP4/[6-311+G**(C,H,O)+Lanl2dz (Ti)] level. All the transition states have been verified by the vibrational analysis and the internal reaction coordinate (IRC) calculations. The doublet potential energy surface has been obtained and the mechanism of the reaction has been confirmed. The results showed that the channel leading to the products Ti—H and [C
3
H
3
O]
+
was dominant.
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Reports
Preparation of Core-shell Cu/Al Powders by Displacement Method
CHENG Zhi-Peng; YANG Yi; LIU Xiao-Di; YANG Yong-Lin; LI Feng-Sheng*
Acta Chimica Sinica 2007, 65 (1): 81-85.
Published: 14 January 2007
Abstract
(
1882
)
PDF
(927KB)(
1716
)
Knowledge map
A kind of novel core-shell Cu/Al powders has been prepared by displacement method, in which nano-sized Cu was made to cover the surface of micron-sized aluminum powders. This reaction happened under the existence of coordination agent—fluoride and protective agent—gelatin. The preparation method and reaction mechanism have been discussed. The microstructure and morphology of the Cu/Al powders were investigated by SEM, XRD, EDS and BET. The analysis results show that this method can prepare the compact shell for Cu/Al powders. The Cu particle coated on aluminum particle was uniform and continuous. The average diameter of Cu crystallites was about 20 nm.
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Cited: CSCD(
8
)
Original Articles
Effect of Sodium Modifier on Activity of Cu/SiO
2
Catalysts for Hydrogenation of Benzaldehyde
XU Hua-Long; DU Jun-Ming; HUANG Jing-Jing; SHEN Wei*
Acta Chimica Sinica 2007, 65 (10): 877-880.
Published: 28 May 2007
Abstract
(
2130
)
PDF
(300KB)(
1512
)
Knowledge map
Cu/SiO
2
catalysts were modified by the sodium by impregnation method, catalytic activity for hydrogenation of benzaldehyde to non-chloride benzyl alcohol was investigated in a continuous flow fixed-bed reactor under atmospheric pressure. It was found that the selectivity of benzyl alcohol was significantly enhanced over sodium modified Cu/SiO
2
catalysts. The optimum loading amount of sodium on Cu-based catalysts is about
w
=1.0%. The Na-CuO/SiO
2
catalysts were characterized by XRD, H
2
-TPR, BET and FT-IR, the results revealed that reducing temperature of CuO was increased after modification by sodium. Meanwhile, the sodium species reduced the intensity and amounts of the acidic centers on catalytic surface, which effectively inhibited the formation of toluene at higher temperature.
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Original Articles
Electrocrystallization of Copper in the Presence of PEG-Cl
-
Additive
GU Min*
,1
; LI Qiang; XIAN Xiao-Hong
2
; QING Sheng-Lan; LIU Ke-Wan
Acta Chimica Sinica 2007, 65 (10): 881-886.
Published: 28 May 2007
Abstract
(
2059
)
PDF
(345KB)(
1426
)
Knowledge map
Linear sweep voltammetry, cyclic voltammetry and chronoamperometry techniques were employed to study the copper electrocrystallization process on a glass carbon electrode (GCE) from acid cupric sulfate electrolytes in the presence of polyethylene glycol and Cl
-
ions. The instantaneous nucleation followed by three-dimensional growth was found for the electrocrystallization from the electrolytes with PEG-Cl
-
. The electrochemical active sites on the GCE surface decrease in the presence of PEG-Cl
-
in electrolytes, which inhibited the electrodeposition and electrocrystallization of copper sharply. However, Cl
-
ions had a strong accelerant effect. With the increase of Cl
-
ion concentration, the diffusion coefficient of Cu
2+
, and the rate of copper electrodeposition and nucleation were promoted. An optimum chloride ion and PEG concentration increased the nuclear density on the GCE surface, which was beneficial to electrodeposits.
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Original Articles
Synthesis of Multibranched Porphyrins with Two-photon Absorption and Intramolecular Energy Transfer
WANG Bao-Zhu; WANG Xiao-Mei*
,1
; JIANG Wan-Li
2
; WANG Zheng-Ping
2
; YANG Ping; HU Da-Wei
2
; YAN Yong-Li
3
; QIAN Shi-Xiong
3
Acta Chimica Sinica 2007, 65 (10): 887-893.
Published: 28 May 2007
Abstract
(
2070
)
PDF
(969KB)(
1195
)
Knowledge map
Three new multibranched porphyrins: 5-(4-nitrobenzoxy)-phenyl-10,15,20-tris-(4-bromophenyl)-porphyrin (TPP-NO
2
), 5-(4-nitrobenzoxy)-phenyl-10,15,20-tris-(4-
N
,
N
-diphenylamino-styryl)- phenyl-porphyrin (TPP-X
3
) and 5,10,15,20-tetra-(4-
N
,
N
-diphenylamino-styryl)-phenyl-porphyrin (TPP-X
4
) were synthesized and characterized by IR,
1
H NMR and MS measurements, respectively. Pumped by 800 nm and 532 nm laser pulses, respectively, the sample solution could emit strong up- and down-conversion fluorescence, wherein the former cound be interpreted by two-photon absorption (TPA) mechanism and the latter was attributed to two-photon absorption and intramolecular energy transfer. TPA cross-section was measured by femtosecond Z-scan technique at 800 nm Ti∶sapphire laser. It was found that TPA cross-section of multibranched porphyrins was enhanced by larger dipole moment difference between the ground- and the excited-state, that is, |Δ
μ
ge
| value, and stronger conjugation effect, that is, π-π conjugation, between porphyrin “core” and branches linked to the porphyrin periphery.
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Cited: CSCD(
1
)
Original Articles
Theoretical Studies of Structures and Absorption Spectra of the Oligomers of 1,4-Phenylene Vinylene and Their Derivatives
WANG Ji-Fen*
,1,2
; FENG Ji-Kang*
,2
; XU Jin-Qiu
1
Acta Chimica Sinica 2007, 65 (10): 894-898.
Published: 28 May 2007
Abstract
(
1886
)
PDF
(304KB)(
1004
)
Knowledge map
The structures of oligomers (PV)
n
(PV=1,4-phenylene vinylene,
n
=2~8) and (PVSD)
n
(PVSD= 2-(1,4-phenylene vinylene)-10-vinylene-spirocyclohexane-1,6-dibenzo[
d
,
f
](1,3)dioxepin,
n
=1~4) were optimized by B3LYP/6-31G. The structures of (PV)
n
(
n
=2~8) tend to be coplanar, with the dihedral angles of no larger than 1°. (PVSD)
n
(
n
=1~4) are twisted in seven-membered-rings, with large dihedral angles about 38° between phenyl rings. The relations between the HOMO-LUMO gaps of oligomers and their chain length were analyzed on the basis of the optimized structures. This relationship is useful to study optical properties of their polymers. The ZINDO and TD-DFT were also used to study the energy gaps. To the importance, the absorption spectra were obtained by both means. The polymeric absorption wavelengths were estimated by extrapolating those of the oligomers to the inverse of chain length to zero. The effective conjugation length was obtained during extrapolation. The result shows that the twisted structure of (PVSD)
n
(
n
=∞) breaks the conjugation length. It has broader energy band than that of (PV)
n
(
n
=∞), that is, the absorption band was blue shifted.
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Cited: Baidu(
3
) CSCD(
1
)
Original Articles
Computational Investigation on the Reaction Mechanism of Atomic Oxygen Radical Anion with Ethylene
YU Feng; ZHAO Ying-Guo
2
; WANG Yong; ZHOU Xiao-Guo*
,1
; LIU Shi-Lin
Acta Chimica Sinica 2007, 65 (10): 899-905.
Published: 28 May 2007
Abstract
(
1973
)
PDF
(380KB)(
1255
)
Knowledge map
The reaction mechanism of atomic oxygen radical anion (O
-
) with ethylene (C
2
H
4
) has been investigated at the G3MP2B3 level of theory. The present calculations demonstrate that O
-
associates quickly with C
2
H
4
to form ion-induced dipole complex, which can subsequently isomerize and decompose to various products, corresponding to molecular anions dissociation and associative electron detachment pathways, respectively. Based on the calculated barrier heights for various channels, the main product pathway is the associative electron detachment channel and the corresponding natural product is
c
-C
2
H
4
O; moreover, the branching ratio of molecular anion dissociation channel is smaller, and the main anion product corresponding to H
2
O production channel is CH
2
=C
-
anion. The present calculations are consistent with the previous experimental results.
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Cited: Baidu(
9
) CSCD(
3
)
Original Articles
Studies on the CMC and the Thermodynamic Function of the Anionic Surfactants in the DMA/Long-chain Alcohol Systems Using a Microcalorimetric Method
ZHANG Hong-Lin; KONG Zhe; YAN Yong-Mei; LI Gan-Zuo*
,2
; YU Li
2
; LI Zhen
2
Acta Chimica Sinica 2007, 65 (10): 906-912.
Published: 28 May 2007
Abstract
(
2273
)
PDF
(350KB)(
988
)
Knowledge map
The critical micelle concentration (CMC) and thermodynamic function of anionic surfactant sodium laurate (SLA) and sodium dodecyl sulfate (SDS) in the
N
,
N
-dimethylacetamide (DMA)/long-chain alcohol systems were studied using titration microcalorimetric method. The power-time curves of SLA and SDS with the presence of long-chain alcohol (
n
-heptanol,
n
-octanol,
n
-nonanol and
n
-decanol) in DMA system were determined. Then, from the curves, the CMC and thermodynamic functions (Δ
H
m
0
, Δ
G
m
0
and Δ
S
m
0
) were obtained by thermodynamic theory. The relationships between temperature, alcohol’s carbon number, concentration and thermodynamic properties were discussed. For SLA or SDS in DMA solution, under the same concentration of alcohol, the values of CMC, Δ
H
m
0
and Δ
S
m
0
increase, while the values of Δ
G
m
0
decrease with the increment of the temperature. Under the same condition of identical temperature and alcohol’s concentration, the values of CMC, Δ
H
m
0
,Δ
G
m
0
and Δ
S
m
0
decrease with the increment of the alcohol’s carbon number. In the presence of the same kind of alcohol, the values of CMC and Δ
G
m
0
increase, but the values of Δ
H
m
0
and Δ
S
m
0
decrease with the concentration increasing in alcohol series at the same temperature.
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Cited: Baidu(
23
) CSCD(
3
)
Original Articles
Catalytic Synthesis of Nitrogen-doped Bamboo-shaped Carbon Nanotubes
WANG Li-Jun*
,1
; XIE Li-Li; LI Yong-Lun
2
; YUAN Hao; LI Qing-Hua; LI Quan-Zhi
3
Acta Chimica Sinica 2007, 65 (10): 913-916.
Published: 28 May 2007
Abstract
(
2176
)
PDF
(2696KB)(
1098
)
Knowledge map
Bamboo-shaped, nitrogen-doped, large-inner diameter carbon nanotubes were synthesized by catalytic method with organic amine as carbon and nitrogen source. By Fe/SBA-15 molecular sieve catalyst, nitrogen-doped bamboo-shaped carbon nanotubes (CN
X
) were synthesized at 973 K high cracking reaction temperature. The effects of Fe content, diethylamine and hexamethylene tetraamine source on the shape and nitrogen-doped content of CN
X
were discussed. Nitrogen-doped bamboo-shaped carbon nanotubes with N/C ratio of 0.26 were synthesized.
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Cited: CSCD(
9
)
Original Articles
Study on the Eruption of Heat for
Escherichia coli
B Aroused by Lanthanum Nitrate and Its Mechanism
LIU Guo-Sheng*
,1,2
; RAN Zhi-Lin; WANG Hai-Lei; LIU Yi*
,2
; SHEN Ping
3
; LU Yan
4
Acta Chimica Sinica 2007, 65 (10): 917-922.
Published: 28 May 2007
Abstract
(
2052
)
PDF
(476KB)(
897
)
Knowledge map
The biological effect of rare earth lanthanum nitrate on the growth of
Escherichia coli
B have been studied with calorimetric method. There were exceptional changes on the growth thermogenic curves for high concentration of lanthanum nitrate, for example the peak high, the total quantity of heat (
Q
) of cultures and the growth rate constants (
k
) increased evidently compared with normal
E. coli
B culture. When the concentration of lanthanum nitrate was 300 and 500 mg/L,
Q
of the cultures reached to 3.89 and 2.54 times of normal culture respectively. The livability of cells and biomass of cultures were measured with biological methods, and the results show that the growth and multiplication of cells were inhibited, and the biomass decreased at high concentration of lanthanum nitrate. These revealed that inhibiting cells discharged more quantity of heat than the normal growing cells, and this phenomenon was named as “eruption of heat”. The mechanism of eruption of heat were suggested that La
3+
ion damages of the outer cell membrane and augment its permeability, proton electron-chemistry potential energy across cell membrane was reduced or could not even be engendered, energy could not be translated into ATP effectively in the course of oxidative phosphorylation and released with heat only, so the cells growth were inhibited finally due to scarceness of current energy ATP.
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Original Articles
Theoretical Investigation on the Separation Characteristics of Electrolyte Solutions with the Nanofiltration Membranes (II): Mixed Electrolyte Solutions
FU Sheng; YU Yang-Xin*; WANG Xiao-Lin
Acta Chimica Sinica 2007, 65 (10): 923-929.
Published: 28 May 2007
Abstract
(
2114
)
PDF
(373KB)(
952
)
Knowledge map
The separation of mixed-electrolyte solutions with nanofiltration membranes was investigated by the combination of the extended Nernst-Planck equation, Donnan equilibrium model and the Poisson-Boltzmann equation. The nanofiltration membrane pores were modeled as slitlike pores characterized by the fixed pore size, pure water permeability and surface electrical potential. The ions in mixed-electrolyte solutions were represented as charged hard-spheres with the hydrodynamic diameters and diffusion coefficients at infinite dilution. The membrane parameters for three commercial nanofiltration membranes (ESNA1-LF, ESNA1 and LES90) were determined from the experimental ion fluxes and rejections of the electrolyte solutions through the corresponding membranes. The theoretical predictions show that diffusion and electro-migration are the main mechanisms of ion transport, and the steric and electrostatic effects are dominant for the ion rejections in nanofiltration (NF) membranes. From comparisons of the predicted ion rejections with the experiment data, it is suggested that the theory should give satisfactory results at low concentration for the mixed-electrolyte solutions containing monovalent ions, while deviations were found at a high concentration or for divalent ions.
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Cited: CSCD(
4
)
Original Articles
Theoretical Study on the Dipole Cycloaddition Reaction of Benzaldoxime with Propinol
LIN Xian-Jie; XU Wei-Ren
2
; WU Jian; LIU Cheng-Bu*
,1
Acta Chimica Sinica 2007, 65 (10): 930-936.
Published: 28 May 2007
Abstract
(
2132
)
PDF
(347KB)(
1062
)
Knowledge map
The reaction mechanism, thermodynamic and kinetic behavior of the dipole cycloaddition reaction of benzaldoxime with propinol have been studied by DFT method at B3LYP/6-31G* level. The results show that there are eight reaction channels, corresponding to eight transition states, in the reaction process. The main parts of all transition states are non-planar five-membered ring, in which the geometry of
Z
-benzaldoxime and
E
-benzaldoxime is maintained partially, but the bond length, bond angle and charge are all changed. The four reaction channels including hydroxyl-type benzaldoxime are endothermic reaction, thermodynamically non-spontaneous process, but the other four reaction channels including ion-type benzaldoxime participation are exothermic reaction and thermodynamically spontaneous process. The latter four reaction channels, which have lower reaction barriers, faster reaction velocities and bigger equilibrium constants than those of the former fours, are the chief reaction channels. Two kinds of products can be obtained in the addition reaction of benzaldoxime with propinol, in which 3-hydroxymethyl-dihydroisoxazol is the main product when reaction equilibrium is reached.
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Original Articles
Study of Air/Fuel Ratio Performance of Low-Precious Metal Pt-Rh Three-Way Catalysts
GUO Jia-Xiu; YUAN Shu-Hua; GONG Mao-Chu; ZHANG Lei; ZHANG Li-Juan; ZHAO Ming; CHEN Yao-Qiang*
Acta Chimica Sinica 2007, 65 (10): 937-942.
Published: 28 May 2007
Abstract
(
1812
)
PDF
(318KB)(
1365
)
Knowledge map
The catalytic activities on C
3
H
8
, CO and NO of low-precious metal of Pt-Rh three-way catalysts prepared by impregnation were studied. The influence of adding CeO
2
-ZrO
2
and BaO into catalysts on air-to-fuel ratio (A/F) was mainly investigated. The reason that A/F was broadened was studied by oxidization reaction, water-gas shift and steam reforming over catalysts. The results indicated that the catalyst merely containing CeO
2
-ZrO
2
had excellent ability of water-gas shift, and steam reforming of C
3
H
8
began to occur at 250 ℃ and maintained 20% of the conversion of C
3
H
8
before 450 ℃. BaO was added to the catalyst containing CeO
2
-ZrO
2
, which could significantly promote water-gas shift and steam reforming and further broadened the three-way working-window of the catalyst. Only addition of CeO
2
-ZrO
2
to the catalysts could promote oxidation reaction activity of CO, but the influence on oxidation of C
3
H
8
was not obvious. Catalyst containing BaO and CeO
2
-ZrO
2
could further promote oxidation reaction activity of CO but did not obviously promote oxidation of C
3
H
8
.
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Cited: CSCD(
4
)
Original Articles
Theoretical Study of Structures, Bonding and Mechanism on Reaction of CpRu(PPh
3
)
2
SSi
i
Pr
3
with SCNR (R=Ph, 1-Naphthyl)
DING Yang-Jun; ZHANG Zhen-Wei; ZHU Shu-Fen; BI Si-Wei*
Acta Chimica Sinica 2007, 65 (10): 943-949.
Published: 28 May 2007
Abstract
(
1959
)
PDF
(1758KB)(
980
)
Knowledge map
The model reaction mechanism of CpRu(PH
3
)
2
SSi
i
Pr
3
with SCNH, derived from CpRu(PPh
3
)
2
- SSi
i
Pr
3
with SCNR (R=Ph, 1-naphthyl), was investigated by using density functional theory (DFT). The structures and bonding involved in the reaction mechanism were analyzed. The phosphine ligand is first dissociated from the reactant to afford an intermediate in the reaction. The sulphur atom in the intermediate has sp
2
hybridization, and the remaining p orbital is symmetrical to the d orbital of the metal center. Thus, the lone pair on the p orbital can have interaction with the d orbital to form a π bond, which leads to the coplanarity of the center of Cp ring, Ru, P, S and Si atoms, rather than the deviation of P, S and Si atoms from the plane. Our results of calculations predict that formation of a four-membered ring containing metal center is the rate-determining step. Decrease of steric hindrance, formation of p conjugation and occurrence of chelation are responsible for the favorable thermodynamics of the reaction.
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Cited: CSCD(
2
)
Original Articles
Comparative Study of Formation Mechanism of K
0.5
Bi
0.5
TiO
3
Powders Synthesized by Three Chemical Methods
HOU Yu-Dong*; HOU Lei; YANG Jian-Feng; ZHU Man-Kang; WANG Hao; YAN Hui
Acta Chimica Sinica 2007, 65 (10): 950-954.
Published: 28 May 2007
Abstract
(
1968
)
PDF
(1355KB)(
1186
)
Knowledge map
Lead-free piezoelectric powders, K
0.5
Bi
0.5
TiO
3
(KBT), were synthesized by sol-gel, hydrothermal and sol-gel-hydrothermal methods, respectively. The structures and morphologies of the powders were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results show that the pure perovskite KBT powders can be obtained by all three methods; however, the formation mechanism and morphology evolution of powders prepared by various processes are quite different. It was deduced that the solid diffusion mechanism was applied to sol-gel process. Due to the high-temperature treatment above 700
℃, the KBT powders produced by sol-gel method had large size with serious agglomeration. The cubically shaped nanopowders were prepared by hydrothermal method, which belongs to dissolution-crystallization mechanism. The
in
-
situ
transformation mechanism was applied to sol-gel-hydrothermal process, and gel clusters played a crucial role in the formation of nanowire morphology.
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Original Articles
Preparation and Property Evaluation of Molecularly Imprinted Polymer Grafted Micro-spherical Resin
LI Bao-Li; ZHANG Min; JIANG Ping; DONG Xiang-Chao*
Acta Chimica Sinica 2007, 65 (10): 955-961.
Published: 28 May 2007
Abstract
(
2317
)
PDF
(1255KB)(
1500
)
Knowledge map
The method of surface grafting of molecularly imprinted polymer on the spherical resin with the living radical polymerization was studied. The surface of poly-styrene-
co
-divinylbenzene resin was grafted with iniferter (initiator-transfer-terminator agent). Under the radiation of UV light, using (-)-ephedrine as the template, methacrylic acid as functional monomer, molecularly imprinted polymer was grafted on the surface of the resin. The influence of the synthetic conditions on the property of the material was investigated. The re-binding experimental result showed that the imprinted polymer grafted resin has affinity and selectivity for the template molecule. The recognition resulted from the imprinting process.
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Cited: Baidu(
16
) CSCD(
14
)
Original Articles
Study on the Interaction between Epirubicin Hydrochloride and Nucleic acid and Its Analytical Application by Resonance Rayleigh Scattering Spectra
LIU Shao-Pu*; WANG Fen; LIU Zhong-Fang; HU Xiao-Li
Acta Chimica Sinica 2007, 65 (10): 962-970.
Published: 28 May 2007
Abstract
(
1919
)
PDF
(403KB)(
917
)
Knowledge map
The interaction between epirubicin hydrochloride and DNA such as calf thymus DNA(ct DNA), salmon DNA(sDNA), herring sperm DNA(hsDNA) was studied using resonance Rayleigh scattering (RRS) method. In pH 2.0 acidic medium, the RRS signal of epirubicin or nucleic acid alone was very weak, but it was enhanced greatly and new RRS spectra appeared when they interacted with each other to form a bound product. There was a little difference of RRS spectra of the bound products for a variety of DNA and their increments of RRS intensity were followed by this sequence, ctDNA≈sDNA>hsDNA. Furthermore the RRS intensity is proportional to the concentration of DNA in a certain range, and so a new method for the determination of DNA with epirubicin by RRS technique was developed. The sensitivity of the method was high with detection limits of different DNA being between 24.0 ng/mL and 28.0 ng/mL and the results of determination of DNA in the synthetic samples with RRS method were satisfactory. The optimum conditions, influence effects and the properties of analytical chemistry of the bound products were also investigated and the reaction mechanism was discussed using RRS associated with absorption and fluorescence spectra.
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Cited: Baidu(
32
) CSCD(
16
)
Original Articles
Synthesis and Theoretical Studies of 3,6-Diazido-1,2,4,5-tetrazine
LI Xiao-Tong; PANG Si-Ping*
,2
; YU Yong-Zhong; LUO Yun-Jun
Acta Chimica Sinica 2007, 65 (10): 971-976.
Published: 28 May 2007
Abstract
(
2093
)
PDF
(344KB)(
1426
)
Knowledge map
3,6-Diazido-1,2,4,5-tetrazine (DAT) has been synthesized from 3,6-bis(3,5-dimethylpyrazol-l- yl)-1,2,4,5-tetrazine by hydrazinolysis and diazotization. The molecular geometries, infrared vibrational spectra, and thermodynamic properties of DAT were calculated using the density functional theory (DFT) method at the B3LYP/6-31G* level. The investigation into simulation and experiment of IR spectra indicates that there exists no azido-tetrazole tautomerism in solid DAT. The thermodynamic parameters including heat capacities, entropies and enthalpies were calculated according to IR spectra, and also the polynomial functions between thermodynamic parameters and temperature were determined. The accurate heat of formation 1088 kJ•mol
-1
of DAT in gas phase was obtained via designed isodesmic reaction in which the tetrazine ring and the azide group have been kept. The data obtained from the present study show a satisfactory detonation performance, with detonation velocity
D
of 8.45 km•s
-1
and detonation pressure
P
of 31.3 GPa, both of which are higher than those of TNT and HMX counterparts.
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Cited: Baidu(
32
) CSCD(
9
)
Original Articles
Synthesis, Characterization and CD Spectrum of Porphyrin Derivatives with Circularly Polarized Property
LUO Kai-Jun
1,2
; JIN Jun
3
; XIE Ming-Gui*
,2
; JIANG Qing
2
; XU Ling-Ling
Acta Chimica Sinica 2007, 65 (10): 977-982.
Published: 28 May 2007
Abstract
(
1925
)
PDF
(319KB)(
1005
)
Knowledge map
A series of porphyrin compounds and Zn complexes with cholesterol ester side chains were synthesized and their UV-Vis and fluorescence spectrum were tested. CD spectrum showed that these compounds in polymethyl methacrylate (PMMA) solid film had circular dichroism property in soret and Q bands because of mutual coupling between chiral cholesterol ester moieties and tetraphenylporphyrin ring, furthermore, it was found that the CD spectrum of cholesterol ester porphyrin compounds was changed along with concentration of these compounds in PMMA solid film.
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Cited: Baidu(
5
) CSCD(
1
)
Original Articles
Studies on the Reconstitution of the Water-Oxidizing Complex in Manganese-depleted Photosystem II with Mn
2
Ca Complex
LING Lin; CHEN Gui-Ying; WANG Wen-Guo
2
; CHEN Hui
2
; LI Shu-Qin*
,1
; CHEN Chang-Neng
2
; LIU Qiu-Tian
2
; KUANG Ting-Yun
Acta Chimica Sinica 2007, 65 (10): 983-988.
Published: 28 May 2007
Abstract
(
1892
)
PDF
(316KB)(
987
)
Knowledge map
The reconstitution of water-oxidizing complex (WOC) with a Mn
2
Ca mixed metal complex in manganese-depleted photosystem II was for the first time reported. The Mn
2
Ca complex was shown to be more effective in restoring electron transfer and oxygen evolution capacity during photoactivation in comparison with that of MnCl
2
. It was proposed that the carboxylato bridge between the Ca and Mn atoms may benefit the formation and stability of the Mn cluster.
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Original Articles
Study of Electron Paramagnetic Resonance Spectra and Impedance Spectra for the Solid Solutions Ce
1-
x
Nd
x
O
2-
δ
LIN Xiao-Min*
,1,2
; LI Li-Ping
2
; SU Wen-Hui
3,4
Acta Chimica Sinica 2007, 65 (10): 989-993.
Published: 28 May 2007
Abstract
(
1944
)
PDF
(342KB)(
975
)
Knowledge map
Solid solutions Ce
1-
x
Nd
x
O
2-
δ
(
x
=0.05~0.55) were prepared by sintering the gel at 800 ℃ for 10 h by sol-gel method. XRD showed that solid solutions Ce
1-
x
Nd
x
O
2-
δ
were crystallized in a cubic fluorite structure. The electron paramagnetic resonance spectra suggested that the content of Ce
3+
ions is decreased with the increasing dopant content
x
in the solid solutions Ce
1-
x
Nd
x
O
2-
δ
, which suggested that doping with lower valence Nd
3+
ions may control the redox of Ce
4+
ions in the solid solutions. The impedance spectra of the solid solutions showed ionic conduction. The conductivities of Ce
0.9
Nd
0.1
O
2-
δ
were 4.25×10
-3
and 1.12×10
-2
S•cm
-1
at 600 and 700 ℃ respectively, and activation energy was 0.82 eV.
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Reports
Study of Potential Energy Function for Ground State N
2
O
-
HUANG Duo-Hui
1,2
; WANG Fan-Hou*
,1
; ZHU Zheng-He
3
Acta Chimica Sinica 2007, 65 (10): 994-997.
Published: 28 May 2007
Abstract
(
1998
)
PDF
(284KB)(
1198
)
Knowledge map
Density functional methods (B3LYP) with 6-311++G(3df, 3pd) basis has been used to optimize the possible structure of N
2
O
-
molecule. The results show that the ground state of N
2
O
-
(
C
s
) molecule is
2
A' state. The equilibrium geometry, dissociation energy and harmonic frequency were calculated, and the results show that
R
N—N
=0.11873 nm,
R
N—O
=0.13012 nm, ∠NNO=133.94448°, and
D
e
=10.3857 eV, and the bending vibrational frequency
ν
1
=656.7488 cm
-1
, symmetric stretch frequency
ν
2
=998.1562 cm
-1
, asymmetric stretch frequency
ν
3
=1684.3093 cm
-1
, respectively. Analytical potential energy function for N
2
O
-
has been derived by using many-body expansion method, which was successfully used for describing the equilibrium geometry of N
2
O
-
.
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Reports
Volumetric Properties of
L
-Alanine in Aqueous LiNO
3
, NaNO
3
, KNO
3
and NaClO
4
Solutions
LIU Chun-Li
1,2
; ZHOU Li
2
; LIN Rui-Sen*
,1
Acta Chimica Sinica 2007, 65 (10): 998-1001.
Published: 28 May 2007
Abstract
(
2253
)
PDF
(274KB)(
926
)
Knowledge map
Densities of
L
-alanine in aqueous LiNO
3
, NaNO
3
, KNO
3
and NaClO
4
solutions have been measured at 298.15 K with an Anton Paar Model 55 densimeter. Apparent molar volumes, limiting partial molar volumes and transfer partial molar volumes have been calculated. Hydration numbers and volumetric interaction coefficients for
L
-alanine were evaluated. The transfer partial molar volumes from water to oxacid salt solutions have been discussed in terms of electrostatic interaction and structural interaction. The results show that all the transfer partial molar volumes of
L
-alanine are positive and increase with the increasing concentration of salts. The reduction in the electrostriction with increasing concentration of salts was confirmed by the decreased hydration number. The contribution of electrostatic interaction to transfer partial molar volumes is predominant. Electrostatic interaction is responsible for the trends of transfer partial molar volumes in NaNO
3
, KNO
3
and NaClO
4
solutions, while in LiNO
3
solutions the influence of structural interaction is prominent.
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Communications
Spontaneous Formation of Vesicle Induced by Hydrotalcite-like Compounds
DU Na; HOU Wan-Guo*
,1,2
; SONG Shu-E
1
Acta Chimica Sinica 2007, 65 (11): 1003-1006.
Published: 14 June 2007
Abstract
(
2031
)
PDF
(666KB)(
790
)
Knowledge map
The spontaneous formation of vesicle induced by charged solid nanoparticle was reported. When mixing 5.0 g/L Mg
3
Al hydrotalcite-like compound (HTlc) sol and 0.02 mol/L surfactant solution of zwitterionic surfactant, dodecyl betaine (C
12
BE), and anionic surfactant, sodium bis(2-ethylhexyl) sulfosuccinate (AOT), with molar ratio of C
12
BE to AOT equal to 3∶2, it was found that Mg
3
Al HTlc nanoparticles with structural positive charges may induce spontaneous formation of vesicles in the volume ratio range of the HTlc sol to the surfactant solution from 1∶9 to 4∶6, and a stable HTlc-vesicle composite was formed. The obtained HTlc-vesicle composite was characterized by negative-staining TEM and dynamic light scattering. Some HTlc nanoparticles were possi-bly enveloped in vesicles.
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Cited: Baidu(
4
) CSCD(
1
)
Original Articles
P(VDF-HFP)-Based Polymer Electrolytes Prepared by High-Voltage Electrospinning Technology
HUANG Zai-Bo; GAO De-Shu*; LI Zhao-Hui; LEI Gang-Tie; ZHOU Ji
Acta Chimica Sinica 2007, 65 (11): 1007-1011.
Published: 14 June 2007
Abstract
(
2296
)
PDF
(1132KB)(
1259
)
Knowledge map
Non-woven membranes based on poly(vinylidene fluoride-co-hexafluoropropylene) [P(VDF- HFP)] copolymer which contain microporous structure have been prepared by electrospinning method. The resulting polymer-ionic liquid electrolytes P(VDF-HFP)/EMIBF
4
possess an ionic conductivity of 8.43 mS•cm
-1
at room temperature and high temperature for initial weight losing over 300 ℃. The electric double-layer capacitors, applying the
polymer-ionic liquid electrolytes as separator, were fabricated and tested. It exhibits excellent electrochemical properties, such as maintaining a specific capacity of 90.67 F•g
-1
even after 500 cycles at 1.0 mA•cm
-2
constant current charge-discharge and enjoying the cycling efficiency of 96.86%.
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Cited: CSCD(
6
)
Original Articles
Theoretical Study on the Structures and Isomerization Mechanisms of 5-Methylcytosine-BH
3
Complexes
JIN Ling-Xia; WANG Wen-Liang*
,1
; WU Dong-Bing
2
; WANG Wei-Na
Acta Chimica Sinica 2007, 65 (11): 1012-1018.
Published: 14 June 2007
Abstract
(
2108
)
PDF
(2081KB)(
1012
)
Knowledge map
The structures and isomerization reactions of 5-methylcytosine-BH
3
complexes have been investigated by the B3LYP and MP2 methods with 6-311+G(d) basis set. 6 complexes and 4 transition states were located. Natural bond orbital analysis was performed to reveal the origin of intermolecular interaction. To obtain the accurate binding energies and potential energy surface, single point energy calculations and BSSE correction were performed. The results indicate that
a
,
b
1
,
b
2
and
c
with BH
3
directly combining N(3), O or N(4) are stable complexes with the binding energies of 104.58, 92.25, 63.49 and 43.41 kJ•mol
-1
, respectively. The complexes may be formed with BH
3
directly combining to 5-methylcytosine as well as with BH
3
entirely transferring on 5-methylcytosine-BH
3
. The influence of cytosine methylation was not obvious on stabilization orders and the energy barriers of isomerization.
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Original Articles
Theoretical Study on Mechanism and Characters of Thermodynamics and Kinetics of the Insertion Reaction of CCl
2
into CH
2
O
LI Zhi-Feng*
,1
; LÜ Ling-Ling; KANG Jing-Wan
2
Acta Chimica Sinica 2007, 65 (11): 1019-1026.
Published: 14 June 2007
Abstract
(
1988
)
PDF
(2660KB)(
992
)
Knowledge map
The insertion reaction mechanism of CCl
2
into CH
2
O has been studied by using the B3LYP/6-311G* and CCSD(T)/6-311G* at single-point. The geometries of reactions, transition states and products were completely optimized. All the transition states were verified by the vibrational analysis and the internal reaction coordinate (IRC) calculations. The results show that the reaction (1) is the dominant reaction path, which proceeds via two steps: (i) two reactants form an intermediate (IM1), which is an exothermal reaction of 9.73 kJ•mol
-1
without energy barrier, (ii) P1 is obtained via the TS1 and the H-shift, in which the energy barrier is 47.32 kJ•mol
-1
. The pressure dependences of the total rate constant were calculated by applying RRKM-TST model in temperature range from 300 to 1900 K. The statistical thermodynamics and Eyring transition state theory with Wigner correction were used to study the thermodynamic and kinetic characters of this reaction. The results show that the appropriate reaction temperature rang is 400 to 1800 K at 1.0 Atm (101325 Pa), in which the reaction has a bigger spontaneity capability, a larger equilibrium constant (
K
) and higher rate con-stant (
k
).
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