bluuebunny/crossref_metadata_2025 huggingface dataset:
The Clar covering polynomial of hexagonal systems II. An application to resonance energy of condensed aromatic Hydrocarbons
Authors: Fu‐Ji Zhang , He‐Ping Zhang , Yu‐Ting Liu
Published: September 2010

The Clar covering polynomial of hexagonal systems is a recently proposed1,2 concept which contains much more topological properties of condensed aromatic hydrocarbons, such as Kekulé structure count, Clar number, first Herndon number, etc. It is shown that this polynomial can be used for calculating the resonance energy of condensed aromatic hydrocarbons with better accuracy.
New Ni(II)Cu(II)Ni(II) trinuclear complexes with an 5=3/2 high‐spin ground
Authors: Ming‐Ming State, Miao , Dai‐Zheng Liao , Zong‐Hui Jiang , Peng Cheng , Geng‐Lin Wang
Published: September 2010

Four new heterotrinuclear complexes have been synthesized and characterized, namely {[Ni(L)2]2[Cu(opba)]}(ClO4)2, where opba denotes o‐phenylenebis(oxamato) and L stands for 1,10‐phenanthroline(phen) (1), 5‐nitro‐l,10‐phenanthroline(NO2‐phen) (2), 2,2′‐bipyridyl(bpy) (S) and 4,4′‐dimethyl‐2,2′‐bipyridyl(Me2bpy) (4). The temperature dependence of the magnetic susceptibility of {[Ni(phen)2]2[Cu(opba)]}(ClO4)23H2O has been studied in the 4–300 K range, giving the exchange integral J—109 cm−1. The HMT vs. T plot exhibits a minimum at about 100 K, characteristic of this kind of coupled polymetallic complex with an irregular spin‐state structure.
The equation of chronoamperometric current on an oblate hemispheroid microelectrode and its verification,
Authors: Guo‐Wang Diao , Liang Li , Zu‐Xun Zhang
Published: September 2010

With the aspect of equivalent diffusion layer an analytical chronoamperometric current equation on an oblate hemispheroid microelectrode for reversible electrochemical condition is derived. To verify this equation the chronoammograms have been obtained with benzoquinone in McIlvaine buffer solution (pH 7.0) at a mercury oblate hemispheroid microelectrode. The experimental results agree with the theoretical conclusions.
Methylene green‐mediated sensor highly sensitive to hydrogen peroxide based on entrapment of horseradish peroxidase in composite membrane of regenerated silk fibroin and poly (vinyl alcohol)
Authors: Xin‐Xin Wu , Hai‐Ying Liu , De‐Yao Qi , Yong‐Cheng Liu , Jiang‐Hong Qian , Sheng‐Hui Liu , Tong‐Yin Yu , Jia‐Qi Deng
Published: September 2010

A novel composite membrane of poly(vinyl alcohol) and regenerated silk fibroin was employed to immobilize horseradish peroxidase (HRP) and IR was used to give a useful insight into the structure of the composite membrane before and after ethanol treatment. A methylene green‐mediated sensor sensitive to hydrogen peroxide was fabricated, based on the composite membrane as immobilization matrix for HRP. Cyclic voltammetry and amperometric measurement were for the first time utilized to demonstrate the suitability of methylene green as an electron transfer mediator between immobilized HRP and a glassy carbon electrode in bioelectrocatalytic reduction of hydrogen peroxide. Performance and characteristics of the sensor were evaluated in respect to response time, detection limit, applied potential and concentration of the mediator. The sensor possesses a variety of characteristics including good sensitivity, rapid response time and low detection of limit of 0.1 μmol/L.
Synthesis of a ball‐chain system C60 aza‐derivative
Authors: Nai‐Xing Wang , Ji‐Sheng Li , Dao‐Ben Zhu
Published: September 2010

Nitrenes generated by thermolysis of alky 1 azides were found to add to C60 in chlorobenzene solvent. The product was isolated by means of silica gel chromatography and identified by field desorption mass spectroscopy and 13C NMR spectroscopy.
A novel secondary metabolite of Chinese red alga Laurencia karlae
Authors: Long‐Mei Zeng , Yong‐Li Zhong , Jing‐Yu Su , Hou‐Ming Wu , Kan Ma
Published: September 2010

A novel skeleton compound benkarlaol (1) was isolated from the red alga Laurencia karlae Zhang et Xia, collected from the Nansha Islands in the South China Sea. Its structure and relative stereochemistry were determined by spectroscopic data, especially extensive ID and 2D NMR experiments.
Photoisomerization of norbornadiene group in a rigid bichromophoric compound initiated by remote keto chromophore: long‐distance through‐bond triplet energy transfer
Authors: Chen‐Ho Tung , Li‐Ping Zhang , Yi Li
Published: September 2010

A diad compound 3β(bicyclo[2,2,1]hepta‐2,5‐diene‐2‐methylcarboxylate‐3‐carboxy)‐an‐drost‐5‐en‐17‐one (NBD‐S‐ONE) was synthesized and its photochemistry was examined. Irradiation of NBD‐S‐ONE in acetonitrile at λ > 300 nm selectively excited the keto chromophore. After intersystem crossing, the triplet energy of the keto group was transferred to the NBD group with 18.6% efficiency via a through‐bond mechanism, resulting in the isomerization of the latter group to the quadricyclane group.
A sensitive xanthine oxidase electrode with silk net for estimating fish freshness
Authors: Tu‐Zhi Peng , Li‐Ju Yang , Lian‐Qing Shen
Published: September 2010

An enzyme biosensor was constructed using a plate platinum electrode and immobilized xanthine oxidase (XOD). Only a very small quantity of enzyme was chemically immobilized on a special silk net. Hydrogen peroxide released during the enzymatic reaction was detected by the electrode at +0.65 V (vs. Ag/AgCl). The electrode was very sensitive to hypoxanthine and its detection limit was 1×10–7 mol/L. When it was applied to the determination of fish freshness, the results agreed well with those obtained by traditional methods‐determination of total volatile basic nitrogen (TVB‐N) and microbial count. A range for estimating the freshness of river fish was suggested.
Synthesis, complexation properties and crystal structure of 4′,5‐dibromo‐o‐xylyl‐17‐crown‐5 ether
Authors: Guo‐Xiang Xiong , Qing‐Fu Zhou , Hui‐Jun Xu
Published: September 2010

4′, 5′‐Dibromc‐o‐xylyl‐17‐crown‐5 ether (2BrB17C5) was synthesized, starting from 1,2‐dibromo‐4,5‐bis(bromomethyl)‐benzene and tetraethylene glycol, and was characterized by 1H NMR, MS and elemental analysis. Pale yellow prismatic single crystal obtained from anhydrous ethanol was investigated by X‐ray structural analysis. The complexation properties toward alkali metal ions were examined using the solvent extraction method and UV absorption spectroscopy. The crown ether was found to be conformationally deformed and oblate‐like and is highly selective for lithium ion.
The rotation and the phase transition in solid C60
Authors: Zhi‐Jin Xu , Ji‐Min Yan
Published: September 2010

The interaction between C60's in solid C60 has been calculated by (exp‐6–1) potential, and the cause and the controlled factor of the high rapid rotations of C60's were discussed. In order to describe the disordered degree of C60 rotation, an equivalent M is introduced. The phase transitions at the ∼260 K and at the ∼90 K are studied from the viewpoint of C60 rotation. The potential barriers of the ordered rotation below the ∼260 K and the disordered rotation above the ∼260 K have been given, and the effect of the external pressure on the temperature of phase transition has also been given.
Ab initio theoretical studies on N28, B4N24, B12N16, and B16N12 with Td symmetry
Authors: Xin‐Tian Jiang , Xu‐Guang Hu , Qian‐Shu Li
Published: September 2010

Structures, energies and vibrational frequencies have been calculated for hollow cage clusters N28, B4N24, B12N16, and B16N12 with Td symmetry using ab initio quantum mechanical methods at the RHF/3–21G level. Each species is predicted to be both chemically and kinetically stable. Skeletal polyhedrons of all considered boron nitride hollow cage clusters are constructed from 5‐and 6‐membered rings.
Structure and magnetic properties of homobinuclear gadolinium (III) complex of isonicotinoyl hydrazone
Authors: Ruo‐Hua Zhang , Hong‐Mei Wang , Dai‐Zheng Liao , Jing‐Tang Chen , Hong‐Gen Wang , Xing‐Kan Yao
Published: September 2010

The crystal structure of [Gd2(μ‐L)3(H2O)2]1.5(NO3)1.5 (OH)5H2O (where L is union of N, N‐Diisonicotinoyl‐2‐hydroxy‐5‐methyl‐isophthalaldehyde dihydrazone) has been determined by X‐ray diffraction method. The complex crystallizes in the monoclinic system, space group P21/c with a=1.6654(3), b=1.6904(3), c=2.8039(6) nm, β=91.30(3), final R factor is 6.3%. The structure consists of [Gd2(μ‐L)3(H2O)2]3+ cation, one and a half nitrate and 1.5 hydroxyl anions and five water molecules. Within dinuclear cation, Gd(III)—Gd(III) is bridged by oxygen and nitrogen atoms of the three ligands, resulting in GdGd distance of 0.36353(2) nm. Gd(III) exhibits a distorted 1333 stack coordination environment. Magnetic susceptibility measurements in the temperature range 300–4 K revealed the occurrence of weak antiferromagnetic exchange interaction between two Gd(III) ions with a J value of—0.22, and g of 1.93.
Y‐Ba‐Cu‐O mixed oxides for production of diphenols in liquid‐solid phase
Authors: Chi‐Biao Liu , Zhen Zhao , Xiang‐Guang Yang , Xing‐Kai Ye , Yue Wu
Published: September 2010

Superconductor mixed oxides were often used as catalysts at higher temperature in gas phase oxidations, and considered not suitable for lower temperature reactions in the liquid‐solid phase; here the catalysis of YBa2Cu3O7±x and Y2BaCuO5±x, in the phenol hydroxylation at lower temperature with H2O2 as oxygen donor was studied, and found that the superconductor YBa2Cu3O7±x has no catalytic activity for phenol hydroxylation, but Y2BaCuO5±x does, even has better catalytic activity and stability than most previously reported ones. With the studies of catalysis of other simple metal oxides and perovskite‐like mixed oxides, a radical substitution mechanism is proposed and the experimental facts are explained clearly, and draw a conclusion that the perovskite‐like mixed oxides with (AO)(ABO3) and (AO)2(ABO3) structure have better catalytic activity than the simple perovskite oxides with (ABO3)3 structure alone, and (AO) structure unit is the key for the mixed oxides to have the phenol hydroxylation activity. No pollution of this process is very important for its further industrial application.
A nonlinear regression model applied to kinetic multi‐component analysis of esters with a SAW‐impedance sensor
Authors: Qing‐Yun Cai , Li Peng , Rong‐Hui Wang , Li‐Hua Nie , Shou‐Zhuo Yao
Published: September 2010

A kinetic nonlinear regression model for multi‐component assay of esters was proposed based on their different alkaline‐catalysed hydrolysis rate. The reaction rate was determined by monitoring the conductance change in solution with a liquid‐purpose surface acoustic wave impedance sensor(SAW). The model was tested theoretically and experimentally with the mixture of methyl acetate and n‐propyl acetate. The experimental detection limit of methyl acetate and n‐propyl acetate (within 10 min) was 0.5 μmol/L and 1.0 μmol/L respectively and the recovery of the sensor system ranged from 93% to 106% (n=6).
Heterocyclic compounds from 3‐(4‐phenyl) benzoyl propionic acid
Authors: A.Y. Soliman , H.M. Bakeer , La. Attia
Published: September 2010

3‐(4‐Phenyl) benzoyl propionic acid was used as the starting material for the synthesis of furanones (2), pyrrolinones (5), pyridazinones (7), benzoxazinones (8) and quinazolinones (9–11). The behaviour of the derivatives of furanones and benzoxazinones toward different nucleophiles is reported.
Study on the reaction of C60 with DL‐valine and cyclohexanone
Authors: Da‐Gui Zheng , Yu‐Liang Li , Zhong Mao , Dao‐Ben Zhu
Published: September 2010

Reaction of C60 with DL‐valine and cyclohexanone in refluxing chlorobenzene under N2 yields three [60]fulleropyrrolidine derivatives (mono‐, bis‐and triadduct) which are characterized on the basis of spectroscopies and cyclic voltammetry. It is found that the ratio of the three products greatly depends on the reaction conditions.
Alkylimido osmium(VI) and ruthenium(VI) porphyrins. Crystal and molecular structures of Os(TTP)(O)(NBut)‐ EtOH and OS(4‐C1‐TPP)(NBut)2
Authors: Li Z‐Ying , Che Chi‐Hling
Published: September 2010

Oxo(tert‐butylimido) or bis(tert‐butylimido)osmium(VI) porphyrins Os(Por)(O)( NBut) and Os(Por)(NBut)2, [Por=meso‐tetrakis(p‐tolyl)porphyrinato (TTP) and meso‐tetrakis(4‐chlorophenyl)porphyrinato (4‐CI‐TPP)] were synthesized by air oxidation of bis(tert‐butylamine)osmium(II) porphyrins [Os(Por)(H2NBut)n (Por=TPP, 4‐C1‐TPP], depending on whether text‐butylamine is present. The bis(tert‐butylamine)ruthenium(II) porphyrins [Ru(Por)(H2NBut)z, Por=TTP, 4‐CI‐TPP] can undergo bromine oxidation to give oxo(tert‐butylimido)ruthenium(VI) complexes in quantitative yields. All these nem complexes were characterized by 1H NMR, UV‐Visible and IR spectroscopy. The X‐ray crystal structures of Os(TTP)(O)(NBut).EtOH and Os(4‐Cl‐TPP)(NBut)2 have been determined. Crystal data: for Os(TTP)(O)(NBu').EtOH: monoclinic, space group P21/c, a=1.3546(6) nm, b=2.3180(3) am, c=1.6817(3) nm, β=90.84(2)°, V=527.97(1) nm3, Z=4. The Os=O and Os=NBut distances in Os(TTP)(O)(NBut).EtOH are 0.1772(7) nm and 0.1759(9) nm, respectively. The average Os=NBut distance of Os(4‐C1‐TPP)(NBut)2 is 0.1775 nm.
Theoretical studies on Lewis acidity scale and bonding character of boron trihalides BX3(X=F, C1, Br, I) by DV‐Xα quantum chemical approach
Authors: Cai Zheng‐Ting , Li Ci‐Ran , Zhang Rui‐Qin , Deng Cong‐Hao
Published: September 2010

The Lewis acidity scale of boron trihalides BX3 (X=F, C1, Br, I) and character of the boron‐halogen bonds have been studied by means of DV‐Xm approach. Present results show that the acid strength of boron trihalides increases in the order BF3<BCl3<BBr3<BI3, in excellent agreement with experiments. Based on boron‐halogen bonding character, the valence of boron atom in boron compounds can be considered M equal to five instead of three which seems to be more reasonable.
Studies on synthesis and kinetics of thermodecomposition of the nickel(II) compounds with Schiff base derived from amino acids
Authors: Li Shu‐Lan , Liu De‐Xin , Yang Zhao‐He
Published: September 2010

Monoaqua salicylaldehyde‐o‐aminobenzoic acid Ni(II) monohydrate (cpl) and monoaqua o‐vanillin‐o‐aminobenzoic acid Ni(II) monohydrate (cp2) were synthesized. The composition and structures of these two compounds were analyzed. Their thermal stability and non‐isothermal kinetics were also investigated by use of TG and DTG curves. The possible reaction mechanisms in their first steps of thermal decomposition reactions were deduced by means of integral and differential methods. Thermodecomposition kinetic equations of the compounds are as follows:

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Studies of the dissociation and the protonation of TB‐chlorosulphophenol
Authors: Zhu Chuan‐Zhmg , Yang Bao‐Lin , Zhao Hong , Gu Wen‐Xiu , Ai Shi‐Yun
Published: September 2010

The dissociation constant of each step for TB‐chlorosulphophenol has been determined by potentiometric method, and the thermodynamic constants. ΔG°, ΔH° and ΔS°, of the dissociation p‐ have been calculated. The protonation constants were measured by the spectrophotometric method. The pH values of various forms of anions of the chromogenic reagent at their concentrations were also calculated.
Comparative studies on the mechanism of uridine phosphorolysis
Authors: Zhao Shan‐Rong , Chen Kai‐Xian , Jiang Hus‐Liang , Wang Qin‐Mi , Ji Ru‐Yun
Published: September 2010

We have used quantum mechanical method to study the transition states(TSs) of uridine phosphorolysis reaction. Comparing the four different reaction pathways and the five transition states obtained, we conclude that enzymatic uridine phosphorolysis takes place mainly according to acid‐catalyzed Sn2 mechanism. The proposed reaction pathway is consistent with many experimental results.
Electrodeposition mechanism of NiMoP alloy in the solution of ammoniac citrate
Authors: Zeng Yue , Yao Su‐Wei , Cao Xue‐Qiang , Huang Hong‐Xin , Zhong Zi‐Yi , Guo He‐Tong
Published: September 2010

The induced codeposition mechanism of Mo, P and Ni from the solution of ammoniac citrate was studied by means of steady‐state polarization, AC impedance and X‐ray Photoelectron Spectroscopy (XPS). The result of electrochemical measurements proved that [NiCit(NHs)2]‐ is the electro‐active species of nickel, though nickel ions exist mainly as [NiCit(NH3)3]− in ammoniac citrate. XPS experiments proved the existence of tetravalent molybdenum corresponding to MoO2 on the surface of mme deposits. The intermediate product, MoO2, WM probably reduced to Mo in the alloy deposit by atomic hydrogen adsorbed on the induced metal nickel. The reduction of H2PO−2 occurs through two distinctive steps with PH3 an an intermediate, which subsequently reacts with atomic hydrogen to form P in the alloy deposit. The electrodeposition mechanism was proposed in this paper.
Electronic factor in electron self‐exchange reaction of hydrated redox ion pairs from thermodynamic data
Authors: Bu Yu‐Xiang , Deng Cong‐Hao
Published: September 2010

An accurate scheme for determining the electronic factor of the electron self‐exchange reaction in solution is presented in this paper. The wed various activation parameters and slopes of potential energy surfaces are obtained in terms of an improved activation model and the accurate potential function determined from the vibrational spectroscopic and thermodynamic data. The coupling matrix elements are determined using numerical integral method over the perturbed double‐zeta Slater‐type state functions. Theoretical results of electronic factor in this work an found in close agreement with those extracted from experimental rate constant data and to be less than unity. Results indicate that outer‐sphere electron transfer reactions in solution involving hydrated transition metal ions are nonadiabatic in nature.
Time‐dependent treatment of intramolecular energy transfer for HeICl complex
Authors: Zhao Xian , Bu Yu‐Xiang , Wu Ai‐Ling , Guan Da‐Ren
Published: September 2010

The time‐dependent golden wave packet method has been used for calculating the decay widths of vibrational predissociation for HeICl complex in the B state with total angular momentum J=0. This is a good example of intramolecular energy transfer. We examine the dependence of the final rotational distribution (partial decay width) of ICI fragment on the stretching excitation. It is found that computed final rotational distributions are weakly dependent on the vibrational level being excited. Unlike the smoothly varying rotational distribution for lower initial vibrational levels, for higher initial vibrational levels the rotational distribution indicates the very pronounced oscillatory structure. The analysis of the rotational distribution as a function of propagation time reveals the predominant role of the final states interaction in determining the final rotational distribution.
A strategy to improve the accuracy of digital simulation for electroanalytical chemistry
Authors: Fang Hui , Chen Hong‐Yuan
Published: September 2010

A strategy for digital simulation methods was presented for solving partial differential equations, called as IPBFP which is to insert M points before the first time point of the usual way, to decrease simulation errors. The theoretical analysis and simulation results show that it can improve the fully implicit method with any dimensionless diffusion coefficient λ, Crank‐Nicolson method with large λ and Saul'yev method with small λ. The IPBFP in convenient to arrange the simulation time points flexibly and reduce calculation time and errors. This approach can combine the merits of non‐uniform time grid and uniform time grid methods in simulation for electrochemical studies.
Semiconductor photoinduced cycloreversion of the dimer of methyl 2‐naphthoate
Authors: Tung Chen‐Ho , Ying Yun‐Ming
Published: September 2010

The dimer of methyl 2‐naphthoate (1) has been found to undergo efficient cycloreversion to its monomer, methyl naphthalene‐2‐carboxylate (2) on illuminated ZnO and TiO2 but not on CdS An electron transfer and cation radical chain mechanism is proposed. Quantum yields, solvent effect., the role of oxygen, and the quenching of the reaction were investigated, and were consistent with the proposed mechanism.
Crystal structure of the complex of trichosanthin with NADPH at 0.172 nm resolution
Authors: Xiong Jim‐Ping , Xu Zong‐Xiang , Wang Yu
Published: September 2010

The orthorhombic crystal structure of the complex of trichosanthin with nicotinamide adenine dinucleotide phosphate has been determined by molecular replacement method using one of the molecules of the monoclinic crystal structure of trichosanthin at 0.27 nm resolution as the search model. The crystallographic refinement at 0.172 nm resolution led to a final R‐factor of 17.4% with root‐mean‐square deviations of 0.0013 nm and 3.8° from the ideal bond lengths and bond angles, respectively. The quality of the structure, the polypeptide chain fold and the comparison of it with that of the monoclinic trichosanthin structure, the location of nicotinamide adenine dinucleotide phosphate, the active site structure as well as the solvent structure are described.
A “one‐pot” synthesis of α‐(p‐toluenesulfonyl)‐aminobenzylphosphinodipeptide derivatives containing a PN bond
Authors: Dai Qing , Chen Ru‐Yu
Published: September 2010

With acetyl chloride as the solvent, the condensation reaction of p‐toluenesulfonamide, an aromatic aldehyde and phenyldichlorophosphine given a reactive intermediate, α‐(p‐toluenesulfonyl)‐aminobenzylphosphinic chloride, which reacts with glycine ethyl ester to give the corresponding phosphinopeptide (6) containing a PN bond directly.
Ab initio band structure calculations on polymers (C5H3X)n (X = CH, N, P, As)
Authors: Lin Chen‐Sheng , Li Jun , Liu Chun‐Wan
Published: September 2010

The ab initio crystal orbital calculations on conjugated aromatic six‐membered rings polymers, namely, poly(p‐phenylene) (PPP), poly(2,5‐pyridinediyl) (PPD), poly(2,5‐phosphabenzene) (PPB) and poly(2,5‐arsabenzene) (PAB) are reported. The comparison of the important electronic properties of these polymers, such as band gap, bandwidth, ionisation potential and electron affinity, indicates that PPP is the best intrinsic semiconductor, and PPD has the best prospects for forming n‐doped conducting materials.
Spectroelectrochemical studies of [Mo(dtc)4][Eu(dtc)4] and [Mo(dtc)4][Er(dtc)4]
Authors: Zhao Yu‐E , Fu Qing‐Hong , Zhang Heng‐Bin , Li Shu‐Jia , Sun Chun‐Ting , Sun Chia‐Chung
Published: September 2010

Redox and spectroscopic properties of the eight‐coordination complexes of molybdenum and the rare‐earth elements Eu or Er with N, N‐diethyldithiocarbamate (dtc) were characterised by cyclic voltammetry and UV‐visible absorption spectra. The complex cation [Mo(dtc)4]+ is more stable than the complex unions [Eu(dtc)4]− and [Er(dtc)4]− in redox processes, and possesses good redox reversibility. The electron transfer number, formal standard electrode potential in the redox process for the complex cation and its diffusion coefficients were obtained by in situ spectroelectro‐chemistry.
Luminescence properties of sol‐gel derived silica gels doped and undoped with RE‐complexes(RE=Eu, Tb)
Authors: Lin Jun , Li Bin , Zhang Hong‐Jie
Published: September 2010

The luminescence properties of silica gels and silica gels doped with two rare earth complexes, Eu(TTA)3 and Tb(o‐CBA)3 (TTA=thenoyltrifluocetate, o‐CBA=o‐chlorobenzoic acid) are reported and discussed. Pure silica gels show a blue luminescence, and the maximum excitation and emission wavelengths depend strongly on the solvents used. Both of the studied rare earth complexes exhibit the characteristic emissions of the rare earth ions in silica gels, i.e., Eu3+ 5D0 → 7 FJ (J = 0, 1, 2, 3, 4), Tb3+ 5D4 → 7 FJ (J = 3, 4, 5, 6) transitions. Compared with the pure RE‐complexes powder, the silica gels doped with RE‐complexes show fewer emission lines of the rare earth ions. Furthermore the rare earth ion (Tb3+) presents a longer lifetime (1346 μs) in silica gel doped with Tb(o‐CBA)3 than in pure Tb(o‐CBA)3 powder (744 μs). The reasons responsible for these results are discussed in the context.
Synthesis and magnetic studies of phthalato‐bridged oxovanadium(IV) binuclear complexes
Authors: Yan Cui‐Wei , Li Yan‐Tuan , Han Qing‐Kui , Liao Dai‐Zheng
Published: September 2010

Six new μ‐phthalato binuclear oxovanadium(IV) complexes, namely [(VO)2(PHTH)‐(L)2]SO4 (L denotes 2,2′‐bipyridine (bpy); 1,10‐phenanthroline (phen); 4,4′‐dimethyl‐2,2′‐bipyridine (Me2 bpy); 5‐nitro‐1,10‐phenanthroline (NO2‐phen); 5‐chloro‐1,10‐phenanthroline (Cl‐phen) and 5‐methyl‐1,10‐phenanthroline (CH3‐phen), where PHTH is the phthalate dianion), have been synthesized and characterized by elemental analyses, IR, electronic spectra, magnetic moments at room temperature and molar conductivity measurements. The temperature dependence of the magnetic susceptibility of complexes [(VO)2(PHTH)(phen)2]SO4 (1) and [(VO)2(PHTH)(CH3‐phen)2]SO4 (2) was measured in 4—300 K range and the observed data were successfully simulated by the equation based on the spin Hamiltonian operator, Ĥ=−2JŜ1·Ŝ2, giving the exchange integrals J=−12.8 cm−1 for 1 and J=−7.9 cm−l for 2. This indicates an antiferromagnetic spin‐exchange interaction between the metal ions within each molecule.
Molecular modeling of rice Rubisco
Authors: Dai Wei‐Wen , Jiang Guo‐Fang , He Yong‐Ning , Xia Zong‐Xiang
Published: September 2010

Molecular model of rice Rubisco has been constructed by molecular modeling method on a computer graphics workstation using graphics software TOM‐FRODO and QUANTA/CHARMm, based on the three‐dimensional structure of spinach Rubisco. The molecular modeling was carried out in the following procedure: amino‐acid sequence substitution; manual adjustment of the initial model; and energy minimization. The three‐dimensional structure of the quaternary complex Rubisco‐CO2·Mg2+·CABP of rice Rubisco has also been modeled and optimized using the program package XPLOR. The main‐chain structure of rice Rubisco does not show obvious difference from that of spinach Rubisco, and the side‐chains are located in the most favorable positions and orientations. The active‐site structures are basically the same for the two species. The mutant Leu335→Arg of rice Rubisco has been designed using the graphics software TURBO‐FRODO and the program package XPLOR. Energy computation suggests that this mutation might increase the carboxylation activity.
Preparation and antibacterial activity of aromatic derivatives of β‐aminopropionic and γ‐aminobutyric acid
Authors: Guan Jing‐Qu , Hu Zun‐Ju , Zou Zhi‐Cben , Wu Zhi‐Guang
Published: September 2010

Ten aromatic derivatives of β‐aminopropionic acid and γ‐aminobutyric acid were prepared. Their compositions and structures were identified by elemental analysis, IR, and 1H NMR. They haw been examined for their antibacterial action against Staphylococcus aureus and Escherichia coli. These compounds showed higher activity than the aromatic derivatives of α‐amino acid which were reported previously. The general conclusion to be drawn is that the distance between amino and carboxylic group in these molecules could affect their antibacterial activity. Furthermore, those compounds with p‐methyl substituent in phenyl ring exhibit higher activity than the others, and all the compounds exhibit higher activity against Escherichia coli and against Staphylococcus aureus.
Synthesis of ribonucleoside analogues containing thio‐substituted 1,3,4‐triazole as heterocyclic base
Authors: Ding Yun , Zhang Jiong , Chen Yao‐Quan
Published: September 2010

New ribonucleoside analogues containing thio‐substituted 1,3,4‐triazole as heterocyclic base have been synthesized via condensation of the central intermediate 1 with various acids, esters, amides, and anhydrides in anhydrous solvent followed by deprotection.
Conformational changes and surface binding property of rat liver Cd5Zn2‐metallothionein
Authors: Huang Zhong‐Xian , Gu Wei‐Qiang , Zheng Qi , Liu Fang , Sun Yao‐Jun
Published: September 2010

A series of conformational changes of native rat liver metallothionein were observed under different ionic strength by1H NMR. Furthermore, binding of magnetic probes to MT gives us an implication that positively charged groups of lysine are not completely folded back towards the inner core of metallothionein, the negatively charged metal‐sulfur core is slightly exposed to the solvent.
A dinuclear molybdenum cluster containing i‐mnt ligand: Synthesis and crystal structure of [Mo2S4(i‐mnt)2] (Et4N)2
Authors: Sun Fu‐Xia , Lu Shao‐Fang , Wu Qiang‐Jin , Huang Xiao‐Ying
Published: September 2010

A dinuclear molybdenum(V) cluster compound (Et4N)2[Mo2S4(i‐mnt)2] (i‐mnt=1,1‐dicyanoethylene‐2,2‐dithiol, [S2C=C(CN)2]2‐) has been prepared by the ligand substitution reaction of Mo2S4(iso‐pr2dtp)2 (iso‐pr2dtp=S2P(OC3H7)2−) with K2(i‐mnt) in the presence of Et4NI. This cluster was characterized by infrared spectrum, UV‐Vis spectrum and single crystal structure analysis. The cluster union [Mo2S4(i‐mnt)2]2‐ possesses Cs, symmetry with a crystallographic mirror plane through two bridging S atoms. By the S …︁ S supramolecular interactions between two adjacent cluster anions the [Mo2S4(i‐mnt)2]2‐ anions are linked to form infinite chains along the b axis. Crystal data: monoclinic, space group C2/m, a=1.8748(6), b=1.5380(4), c=1.4322(5) nm, β=112.02(2)°, V=3.823(4) nm3, Z=4, Dc=1.50 g/cm3. The final R=0.038 and Rw=0.053 for 3015 observed unique reflections.
27‐Ald‐triterpenoid saponins from Adina rubella
Authors: Fan Gae‐Jun , He Zhi‐Sheng , Wu Hou‐Ming , Xu Jing‐Fei
Published: September 2010

Four new triterpenoid saponins were isolated from the roots of Adina rubella Hance. They were characterized as adinaic acid 3β‐[α‐L‐rhamnopyranosyl(1→2)‐β‐D‐glucopyranosyl(1→2)‐β‐D‐glucurono‐pyranoside‐6‐O‐methyl ester]‐2‐O‐β‐D‐glucopyranoside, adinaic acid 3β‐O‐[a‐L‐rhamnopyranosyl(1→2)‐β‐D‐glucopyranosyl(1→2)‐β‐D‐glucuronopyranosid‐6‐O‐butyl ester]‐28‐O‐β‐D‐glu‐copyranoside, adinaic acid 3β‐O‐[β‐D‐glucopyranosyl(1→2)‐β‐D‐glucopyranosyl]‐(28→ l)‐β‐D‐glucopyranosyl(1→6)‐β‐D‐glucopyranosyl ester, 27‐hydroxyursolic acid 3β‐O‐[α‐L‐rhamnopyranosyl (1→ 2)‐β‐D‐glucopyranosyl(1→2)‐β‐D‐glucuronopyranoside‐6‐O‐methyl ester]‐28‐O‐β‐D‐glucopyranoside. Their structures wen elucidated by spectral methods, specially with the aid of 2D NMR techniques. Their complete assignments of the 1H and 13C NMR signals were carried out.
Synthesis and spectroscopic properties of a novel zinc phthalocyanine with four 17‐membered crown ether voids
Authors: Xiong Guo‐Xiang , Shen Shu‐Yin , Ye Jian‐Ping , Zhou Qing‐Fu , Xu Hui‐Jun
Published: September 2010

A novel zinc phthalocyanine containing four 17‐crown‐5 ether voids(17C5ZnPc) has been synthesized and characterized. UV‐visible absorption and fluorescence emission spectra and as sociated photophysical parameters have been determined. In contrast to most of the crown ether substituted phthalocyanines, no cofacial dimer formation is observed in the presence of alkali metal salts. In addition to the fluorescence at 710 nm from S1, a strong upper excited state (Soret S2) emission around 424 nm has been detected for the first time in the phthalocyanine series. Fluorescence decay of S1 and S2 emission can be analyzed by mono‐ and biexponential fits respectively. X‐ray structure analysis showed that the crown ether unit is conformationally deformed and oblate that may account for the unusual spectroscopic properties.
Synthesis of new heterocycles 1,3,2,6‐dioxaphosphaselenacyclooctanes
Authors: Li Jin‐Liang , Tian Bing , Zhao Chang‐Qiu , Wang Yong‐Mei , Meng Ji‐Ben , Wang Hong‐Gen
Published: September 2010

New phosphorus‐ and selenium‐containing heterocycles, 1,3,2,6‐dioxaphosphaselenacyclooctanes (1a—1h), were synthesized by the reaction of bis(2‐hydroxyethyl)selenide with RP(X)Cl2 whore R=alkoxyl, aroxyl, aryl and X=O or lone pair. Their structures were determined by spectroscopies and elemental analyses and finally confirmed by the X‐ray crystallographic analysis of 1c. The molecular structures of the heterocycles were discussed in term of conformational analysis.
A new series of chiral catalysts for the enantioselective borane reduction of ketones
Authors: Shen Zong‐Xuan , Zhang Ya‐Wen , Lu Jun , Xu Xue‐Nong , Lu Cheng‐Rong
Published: September 2010

A new series of 1,3,2‐oxazaborolidine catalysts substituted in position 4 by the (CH3)3C(CH2)n group (n=2, 3, 4, 5) were synthesized and applied to the borane reduction of prochiral ketones. The relationship between catalyst structure and enantioselectivity was discussed.
Study on the sulfinatodehalogenation of BrCF2CF2R
Authors: Hu Qiao‐Sheng , Hu Chang‐Ming , Huang Wei‐Yuan
Published: September 2010

Sodium dithionite initiated sulfinatodehalogenation of BrCF2CF2R is studied.
Expected and unexpected etherification of 2‐per(poly)fluoroethyl 4‐substituted phenol with β‐haloethanol
Authors: Yu Hong‐Bin , Li Rui‐Qing , Huang Wei‐Yuan , Mak Thomas , Zhou Zhong‐Yuan C. W.
Published: September 2010

Under different reaction conditions, the expected and unexpected reaction products (of which X‐ray crystallographic structure was presented) of etherification of 2‐per(poly)fluoroethyl 4‐substituted phenol with β‐haloethanol can be obtained respectively.
Investigation on the computation of atomic multipole moments with the modified cumulative potential‐derived semiempirical method
Authors: Xu Li‐Jin , Zhu Chuan‐Bao , Yan Ji‐Min
Published: September 2010

The suitability of calculating atomic multipole moments from AM1 wave functions by cumulative potential‐derived method has been investigated. It is shown that this method has a faster convergence of the fitting process and gives a better description of the charge distribution than the original PD method. Atomic charges obtained in this way are of comparable quality with 6‐31G* data and the calculated dipole moments are closer to the experimental data than the values computed directly from the AM1 charges. The results demonstrate that the atomic multipole moments higher than monopole moment can be used to supplement the atomic charge to obtain a more accurate description of charge distribution. For the sake of comparison, both the Williams fitting potential surface and the Connolly one are used in the calculation.
A novel formula for location of double bond in alkenyl acetates and alcohols based on mass spectral data of dimethyl disulfide derivatives
Authors: Xiao Jun‐Hua , Yuan Gu , Yang Li‐Zhang , Sun Yu‐Fang , Wang Xian‐Lun
Published: September 2010

A new formula was presented for locating double bond position in dodecenols, tetradecenols, hexadecenols and their acetates, based on mass spectral data of dimethyl disulfide derivatives. In this procedure, molecular ion and base peak ion were utilized as characteristic parameters to identify the positional isomers. The method was tested with mass spectra of 25 dimethyl disulfide derivatives of mono‐unsaturated acetates and alcohols, and the original double‐bond position in each isomer was located unambiguously.
Synthesis of some new germasesquioxides by intramolecular catalytic Mannich‐type reactions
Authors: Zhang Zhong‐Biao , He Da‐Yong , Chi Guo‐Chen , Chen Ru‐Yu
Published: September 2010

A convenient procedure for the preparation of some new germasesquioxides containing phosphonyl groups carried by an intramolecular catalytic Mannich‐type reaction is reported.
Asymmetric total synthesis of (+)‐1‐deoxy‐6‐epi‐castanospermine
Authors: Yi‐Ming Xu , Wei‐Shan Zhou
Published: September 2010

(+)‐l‐Deoxy‐6‐epi‐castanospermine was asymmetrically synthesized in ten steps from a‐furfuryl amine derivative 6 in 2.9% overall yield. The kinetic resolution of a‐furfuryl mine derivative 6 and Sharpless AD reaction of 14 were used as key steps.
Synthesis of unsaturated phosphatidyl inositol‐3,4,5‐trisphosphate
Authors: Shoichiro Ozaki , Xiang‐Zheng Kong , Yutaka Watanabe , Tomio Ogasawara
Published: September 2010

Phosphatidylinositol polyphosphate (PIPx) are related with tyrosine kinase activation and cell proliferation and carcinogenesis. PIPx is an important target compound for synthetic organic chemist. PIPx having saturated fatty acid components have been reported. Recently we have succeeded in the synthesis of phosphatydylinositol‐3,4,5‐trisphosphate with unsaturated fatty acid component by the reaction of diethyl chlorophosphite with 1,2‐di‐O‐cyclohexylidene‐3,4‐0‐(tetraisopropyldisiloxane 1,3‐diyl)‐6‐O‐(4‐oxopentanoyl)‐myo‐inositol.
Highly efficient catalysts derived from planar chiral ferrocenes for asymmetric transfer hydrogenation of ketones
Authors: Xiang‐Dong Du , Li‐Xin Dai , Xue‐Long Hou , Li‐Jun Xia , Ming‐Hua Tang
Published: September 2010

Planar chiral ferrocenes 1 and its diastereoisomer 2 were found to be good lig‐ands for. the ruthenium catalyzed asymmetric transfer hydrogenation of ketones with i‐PrOH as hydrogen source under refluxing in the presence of sodium hydroxide. The results showed that the absolute configuration of alcohol seemed to be governed by the central chirality in the oxazoline ring instead of the planar chirality. At a ratio of 1:2 for Ru:ligand, 3000:1 S/C and >100,000/h−1 TOF were observed for acetophenone. For propiophenone 99% yield and 85% e.e. were obtained.
Studies on the synthesis and magnetic property of binuclear oxovanadium(IV) complexes bridged by chloranilato group
Authors: Yan‐Tuan Li , Cui‐Wei Yan , Dai‐Zheng Liao
Published: September 2010

Six novel oxovanadium(IV) binuclear complexes have been synthesized and characterized, namely, [(VO)2(CA)L2]SO4 [L denotes 5‐methyl‐1,10‐phenanthroline (Me‐phen); 2,9‐dimethyl‐1,10‐phenanthroline (Me2‐phen); 5‐chloro‐1,10‐phenanthroline (Cl‐phen); diaminoethane (en); 1,3‐diaminopropane (pn) and 1,2‐diaminopropane (ap) respectively.], where CA represents the dianion of chloranilic acid. Based on elemental analyses, molar conductivity and room temperature magnetic moment measurements, IR and electronic spectral studies, it is proposed that there complexes have CA‐bridged structures and consist of two vanadium(IV) ions in a square‐pyramidal environment. The complexes [(VO)2(CA)(Me‐phen)2]SO4 (1) and [(VO)2(CA)(Me2‐phen)2]SO4 (2) were characterized by variable temperature magnetic susceptibility measurements (4∼300 K) and the observed data were fitted to the modified Bleaney‐Bowers equation by the least‐squares method, giving the exchange integral J=‐15.8 cm−1 for 1 and J=‐10.6 cm−l for 2. This result indicates that there is a weak antiferromagnetic spin‐exchange interaction between the two VO2+ ions within each molecule.
Investigation of carbon‐13 nuclear magnetic resonance spectra‐structure correlation based on novel atomic distance‐edge (ADE) vector
Authors: Shu‐Shen Liu , Chen‐Zhong Cao , Zhi‐Liang Li
Published: September 2010

A set of novel graph‐theoretical parameters, called the atomic distance‐edge (ADE) vector, was developed. Baaed on the connecting C‐C bond number between central carbon atom and the other ones, various carbon atoms of alkanes were classified as four types, i.e., type 1, 2, 3 and 4 for primary, secondary, ternary and quaternary carbon, respectively; and then four regression equations were obtained to link carbon‐13 chemical shift (CS) of each type of atoms. Furthermore, these regression models were used to predict the carbon‐13 nuclear magnetic resonance spectra of alkanes and it was found that the estimated CS were in agreement with the experimental results.
Transfer of lanthanum ion across the adsorption of emulsifier OP at the water‐nitrobenzene interface
Authors: Jun‐Wei Di , Hong‐Lan Cai , Rui‐Xi Fan
Published: September 2010

The transfer of lanthanum ion facilitated by diantipyrylmethane (DAM) across the water/nitrobenzene (w/nb) interface and the adsorption of emulsifier OP at the w/nb interface has been studied by the cyclic voltammetry. The mechanism of the charge transfer reactions is discussed. It has been concluded that the transfer of rare earth metal ion (La3+) facilitated by neutral ionophore (DAM) at the w/nb interface is E mechanism and the nonionic surfactant (emulsifier OP) can participate in the charge transfer process M an ionophore, charge transfer catalyst and inhibitor.
Optimization separation of five phosphoamidothioate enantiomers using a series of silica and chiral column by high‐performance liquid chromatography
Authors: Ru‐Yu Gao , Hua‐Zheng Yang , Jun‐Min Huang , Qin‐Sun Wang
Published: September 2010

A computer‐assisted method is described for optimization of multi‐component, mobile phase selection for separation of five phosphoamidothioate enantiomers with a series of silica and chiral columns in normal phase HPLC. The method is based on the triangular solvent selection concept using a statistical scanning method. The optimization of the separation over the experimental region is based on a special polynomial estimation from seven experimental runs, and resolution (Rs) is used as the selection criterion. Excellent agreement was obtained between predicted and experimental data.
Organic solvent enhanced a‐helical formation of a nonadecapeptide derived from Trichosanthin (TCS 182–200)
Authors: Hong‐Yu Hu , Zi‐Xian Lu , Yu‐Cang Du
Published: September 2010

A model peptide, TDK, was studied by circular dichroism to elucidate the effect of organic solvent on α‐helical formation. The a‐helicities enhanced by various alcohol solvents, especially fluorine‐substituted alcohols were systematically compared. The relations between a‐helical formation of a peptide and external environment were also discussed in detail. These environmental elements mainly include hydrophobicity, dielectric constant and acidity of the solvents.
Asymmetric synthesis of some new tetrahydroisoquinolinium salts
Authors: Qi‐Dong You
Published: September 2010

Several new tetrahydroisoquinolinium salts, analogues of atracurium, were designed and synthesized. These compounds were prepared from optically pure tetrahydropapaverine and hexamethylene diglycidate.
1,3‐Dipolar cycloaddition reaction of two different azomethine ylides to C70
Authors: Da‐Gui Zheng , Yu‐Liang Li , Lou‐Zhen Fan , Feng‐Ying Li , Yong‐Fanga Li , Dao‐Ben Zhu
Published: September 2010

1,3‐Dipolar cycloaddition to C70 of an azomethine ylide, which was generated in situ from refluxing a mixture of cyclohexanone and DL‐valine in chlorobenzene under N2, afforded a monoadduct and a bisadduct. Even for longer reaction time, however, only monoadduct waa obtained from the reaction of C70 with an azomethine ylide generated from refluxing a mixture of 2‐undecanone and 2‐aminoisobutyric acid in chlorobenzene under N2. The electrochemical properties of all the products were studied by cyclic voltammetry.
Theoretical investigation of the decomposition of monofluoromethanol
Authors: Hua Hou , Jing‐Zhong Guo , Chuan‐Pu Liu , Yue‐Shu Gu
Published: September 2010

Ab initio calculations have been used to study the decomposition pathways of monofluromethanol. Equilibrium geometries and transition state structures were optimized at the HF/6‐31G(d) and MP2/6‐31G(d) levels. Single point energies were obtained at different levels of theory. The most favorable reaction to dissociation is the 1,2‐HF elimination which is consistent with the experimental results.
Ozone reduction at Nafion modified Au electrode and the measurement of ozone concentration in highly resistive solutions
Authors: Pei‐Fang Liu , Li‐Bai Wen
Published: September 2010

The mass transport and charge transfer kinetics of ozone reduction at Nafion coated Au electrodes were studied in 0.5 mol/L H2SO4 and highly resistive solutions such as distilled water and tap water. The diffusion coefficient and partition coefficient of ozone in Nafion coating are 1.78×10−6 cm2·s−l and 2.75 at 25°C (based on dry state thickness), respectively. The heterogeneous rate constants and Tafel slopes for ozone reduction at bare Au are 4.1×10−6 cm·s−1, 1.0×10−6 cm·s−1 and 181 mV, 207 mV in 0.5 mol/L H2SO4 and distilled water respectively and the corresponding values for Nafion coated Au are 5.5×10−6 cm·s−l, 1,1×10−6 cm·s−1 and 182 mV, 168 mV respectively. The Au microelectrode with 3 μm Nafion coating shows good linearity over the range 0–10 mmol/L ozone in distilled water with sensitivity 61 μA·ppm−1·cm−2, detection limit 10 ppb and 95% response time below 5 s at 25°C. The temperature coefficient in range of 11–30°C is 1.3%.
Study of chiral recognition mechanism of O, O‐diethyl (p‐methylbenzenesulfonamindo)aryl(alkyl)‐methylphosphonates by HPLC with a series of CSPs
Authors: Guo‐Sheng Yang , Qing Dai , Ru‐Yu Gao , Qin‐Sun Wang , Han‐Xi Shen
Published: September 2010

Five chiral stationary phases (CSPs) were used to separate the enantiomers of a series of O,O‐diethyl (p‐methyl‐benzenesulfonamindo)‐aryl(alkyl)‐methylphosphonates. A chiral recognition mechanism was presented to explain the resolution of these compounds. Results show that CSP with strong π‐acceptor 3,5‐dinitrobenzoyl group and high steric hindrance has the best resolution ability in chiral separation of O,O‐diethyl (p‐methylbenzenesulfonamindo)‐aryl(alkyl)‐methylphosphonates. When a CSP has just a strong π‐acceptor 3,5‐dinitrobenzoyl or high steric hindrance it does not have good chiral resolution ability. The chiral recognition is more difficult when the CSP has more than one asymmetric center.
Enantioselective allylation of aldehydes with chiral allyl organolanthanide reagents
Authors: Chang‐Tao Qian , Tai‐Sheng Huang
Published: September 2010

The first example of enantioselective allylation of aldehydes with chiral allyl organolanthanide reagents has been achieved in high chemical yield and moderate optical purity (up to 54% e.e.).
Standard Gibbs energies of transfer of rubidium tetraphenylborate from water to straight‐chain n‐alkanols
Authors: Li‐Zhuang Zou , Xiao‐Ling Wang , Feng‐Ge Wang , Pi‐Jian Zhang , Xiang‐Kun Guo , Bao‐Xue Zhou , Song‐Sheng Qu
Published: September 2010

Solubilities of ribidium tetraphenylborate in water, methanol, ethanol, 1‐propanol, 1‐butanol, 1‐pentanol, 1‐hexanol and l‐octanol at 288.15, 298.15, 308.15, 318.15, 328.15 K have been determined by spectrophotometry. The standard Gibbs energy of transfer of ribidium tetraphenylborate from water to straight‐chain n‐alkanols and the primary medium effect of rubidium tetraphenylborate from 288.15 to 328.15 K have been calculated. Furthermore, the contribution of microscopic interactions to the standard Gibbs energy of transfer of rubidium tetraphenylborate in calculated and discussed.
A quantum scattering study of collinear state‐testate reaction probabilities for the F + H2(v) → HF(v') + H system
Authors: Wen‐Cai Lu , Zheng‐Ting Cai , Cong‐Hao Deng
Published: September 2010

A new quantum scattering approach (linear combination of arrangement channels‐scattering wavefunction, LCAC‐SW) proposed by Deng and his co‐workers is used to calculate collinear state‐to‐state reaction probabilities for the F + H2(v) → HF(v') + H system. Several interesting problems such M threshold energy, compound states and enhance by translational energy of the reactants and the vibration excitation of products are discussed and they are compared with other theoretical investigations reported in the literature. It is shown that the LCAC‐SW approach is the successful one of quantum scattering methods.
NMR titration and molecular model MOPAC calculation of protonation processes of two MRI ligands
Authors: Shan‐Rong Zhang , Xin‐Yu Li , Wei‐Dong Liu , Feng‐Kui Pei
Published: September 2010

The protonation process of two DTPA bis(amide) derivatives, DTPA‐BDMA and DTPA‐BDEA, was studied by using 1H NMR titration and MOPAC calculation. Their protonation process was proposed in the order of the central amine, the terminal amines, the central carboxyl, the terminal carboxyl, the other terminal carboxyl and central amine. During the protonation of the terminal amine, them existed a large fraction of proton transfer from the central amine to the other terminal amine.
Quasiclassical trajectory study of the reaction NH(X3Σ−) + H → N(4S) + H2
Authors: Li‐Jin Xu , Xue‐Bin Wang , Ji‐Min Yan , Fan‐Ao Kong
Published: September 2010

The dynamics of the NH + H → N + H2 reaction has been investigated by means of the 3D quasiclassical trajectory approach by using the LEPS potential energy surface. The calculated rate coefficient is in good agreement with the experimental value. The reaction was found to occur via a direct channel. The product H2 has a cold excitation of rotational state, but has a reverse distribution of the vibrational state with a peak at v=l. Based on the potential energy surface and the trajectory analysis, the reaction mechanism has been explained successfully.