The mass spectra of both positive and negative charged Ta-containing ions from laser ablation of Ta2O5 were measured using a time-of-flight mass spectrometer. Formation of ionic Ta-containing oxides such as TaO3+ and TaO4+ from Ta2O5 ablation in ambient O2 were observed for the first time. The influence of ambient O2 pressure on the intensities of ablated Ta-containing ions has also been studied. It is found that the subsequent oxidation reactions were involved in the ablation of Ta2O5 at different O2 pressure. The enthalpies of possible oxidation reactions were theoretically calculated, and the possible formation reactions of the ionic Ta-containing oxides are discussed.

We report here the measurements of valence electron structure for the n-butane (C4H10) using high resolution (ΔE=0.9 eV FWHM, ΔP=0.1 a.u.) (e,2e) spectrometer. The impact energy was 1200eV plus binding energy (i.e. 1206 to 1232 eV) and symmetric non-coplanar kinematics was employed. The inner-and outer-valence energy spectrum is in agreement with published Photoelectron data. The experimental momentum profiles have been compared with calculations obtained using Hartree-Fock method with the minimum basis set and a high-level basis set, and also using density functional theory (DFT) density methods with a high level basis set. The agreement between theory and experiment for shape of orbital electron momentum distributions is generally od.

Au nanoparticles are assembled on ld substrate modified with p-aminothiophenol. AFM measurements show that the coverage of Au nanoparticles is closely related to the pH value of colloids. The SERS intensity also changes with the pH value, which is well consistent with the pH-dependent change of the coverage. In alkaline solution, the amino group is not protonated, and Au particles can not be adsorbed on the substrate: while under acidic environment, protonation makes the amino group positively charged and the adsorption gets easier. The interaction between the particles and the substrate is considered to be electrostatic. The PH value, which controls the coverage of Au nanoparticles, affects both the protonation of the amino group and the quantity of the negative charge of Au particles.

The changes of chemical states of sulfur element in photographic gelatin before and after electroless depositions are studied using in situ Ar+ beam sputtering and ESCA scanning techniques of X-ray Photoelectron Spectroscopy in this paper. The depth distributions of copper and ld within electrically conductive layer produced by electroless copper deposition are carried out, and the mechanism of electroless copper deposition catalyzed by ld in photographic gelatin is investigated. The results indicate that under acidic condition(pH=3.20), methionine sulfone in gelatin macromolecule still having relatively high reducing power and methionine of gelatin macromolecule, which are both oxidized to methionine sulfoxide, reduce Au3+ finally to colloidal ld which is the catalytic center of electroless copper deposition at the initial stage of reduction. Afterwards the reduction deposition of Cu2+ continues because of the autocatalysis of new-formed copper. Under basic condition (pH=12.50) in the process of electroless deposition, methionine sulfoxide in gelatin is partly reduced to methionine by reductive agent HCHO.

AM1 method has been used to study tile mechanism of coloration processes of salicylideneaniline derivatives with different substituents. It has been found that the substituents have not obvious effect on tile structure of the reaction system. All the N-salicylideneanilines investigated have the enol-like structures at room temperature and the coloration processes under by two steps and the colored products have the unstable keto-like structure which reverses to the cis-keto structure quickly.

The reactions of CIONO2 with mH2O (n=1.2,3) as model reactions of CIONO2 on ice surface were investigated by theoretical ab initio calculations. In the gas phase, the barrier of the reaction of CIONO2 with H2O is 284.8 kJ•mol-1 at MP2/HF/6-31G(d) level. The barrier of the reaction is dramatically reduced as the number of water involved in the reaction is increased. The experimental result of the precursor of the product HOCl in the reaction of CIONO2 on ice surface was explained. On the line of multi-molecule-formed transition state (MTS) mechanism, the possibility of hydration further reducing the barrier was discussed. The MTS mechanism can explain all the experimental results up to date.

The monomer and excimer fluorescence bands recorded in aqueous solution of a new kind of fluorescence chemosensor which have the ability of recognition exhibit an "isosbestic" point over certain limited ranges of temperatures. The temperature dependence of their excimer formation was studied. The mechanism of the transformation between monomer and excimer and the excimer geometrical configuration have been proposed. From the temperature conefficient of the ratio of excimer to monomer fluorescence intensities at the isosbestic wavelength the value of enthalpy and entropy in the process of transformation can be estimated. The repulsive energy between unexcited molecule in the excimer configuration contributes to the excimer formation of these fluorescence chemosensor. These results provide a base for their applications.

Two competitive pathways of the stepwise reaction of vinyl acetylene (VA) with nitric oxide were studied by UAM1 method. The calculations showed that the path Ⅰ(NO attacks VA to form a six-membered cyclic transition state through the 1,4-addition reaction for the first two steps, then decomposed at the last two steps to form CH2O, propionitrole and H ratical) is easier to initiate than path Ⅱ(NO approaches VA with a 1.2-addition to form a four-membered cyclic transition state at its first two steps). However, path Ⅱcall easily take place at its final two steps to form acrylonitrile once it has been initiated.

 The mass-selected excitation spectra for parent ion CS and the fragmentation ions CS+, S+ and C+ are obtained by using the resonance-enhanced multiphoton ionization (REMPI)of CS2 in the range 242 260nm. It is shown that the diffuse bands of CS in range of λ<246.4nm are mainly from the two-photon ionization of CS2. It has been reasonably assumed from the assignments of excitation spectra for the fragments that the neutral CS and S are produced by the photodissociation of CS2 in the process, that is, (1) the bands of CS+ are mainly due to the (1+1) resonance-enhanced ionization via the one-photon transition of the fragment CS, (2) besides part of S+ spectral peaks are from the dissociation of CS+, most of S+ spectral peaks are due to the (2+1) resonance-enhanced ionization via the two-photon transition 3p3 (2D0) 4p, 3p3 (4S0) np (n=6,7,8)←3p4 3PJ (J=2,1,0) of S atoms.

The catalytic activity of hydroformylation of 1-hexene over SiO2-supported TPPTSRh(acac)(CO)2 (SAPC) was found to be evidently promoted when a proper amount of water-vapor was introduced into the reactant. Characterization results by using MAS NMR 31p spectra revealed that there were three types of phosphine species in the as-prepared SAPC: uncoordinated ligand TPPTS (over 70 mol%), surface complex {Rh(CO)(TPPTS)2} (chemical shift at δ=32.4, about 15 mol%), and unknown (about 10 mol%). By pre-treatment at 373 K for 2 under dry-snygas or at 333 K for 2 h under wet-syngas, the amount of phosphine species of the surface complex{Rh(CO)(TPPTS)2} was slightly increased to 20-30mol%, accompanying a few changes in ratios of the other phsophine species. When the SAPC was pre-treated at 373 K for 2 h under wet-syngas, however, the phosphine species at chemical shift of 32.4 was increased by over 40 mol% due to the in-situ formation of the surface complex {Rh(CO)(TPPTS)2}. It was found that the peak at δ=32.4 was also a principal one in the MAS NMR 31P spectra of the working SAPC, which demonstrated that the surface complex of {Rh(CO)(TPPTS)2 } would be a catalytic active species for olefin hydroformyaltion. After hydroformylation for 43 h, the deactivation of the catalyst occurred, corresponding to the observations of a broadness in peak ascribed to the surface complex of {An(CO)(TPPTS)z} in the MAS NMR 31P spectra, indicating that there existed de-coordination of the surface complex and oxidation of the ligand TPPTS during the reaction. The results suggest that a proper amount of water-vapor was able to accelerate the formation of active Rh-complex on the catalyst surface and thus increase the catalytic activity, whereas, it could be inevitably to cause the de-coordination of the surface complex and the oxidation of phosphine ligand under the reaction condition, hence leading to the deactivation of the catalyst.

One-electron reduction potentials could be use as the critical-criteria of charge transfer protect and sensitization. The One-electron reduction potentials of four Tea Polyphenol derivatives using duroquinone as the reference compound have been measured with the technique of pulse radiolysis, the one-electron reduction potentials of EGCG, GCG, GC, C are-316, -325, -328,-326mV, respectively. Acccording to the criteria of charge transfer of protection and sensitization, compared with one-electron reduction potential of thymine (-1100mV), EGCG, GCG, GC and C can be used to protect efficiently the target molecule thymine from the damage induced by electron addition.

The CMCs, γcmcS and micropolarities of aqueous solutions of sodium undecenoate(UNDE) and sodium undecanoate (UNDA) have been studied by surface tension measurement and fluorescence method. It is revealed that double bond at the en of hydrophobic chain weakens its hydrophobicity, hence lowering the effectiveness of micelle formation and that of surface tension reduction. The limited adsorption amount is less, while micropolarity higher, in UNDE solution than those in UNDA's. Therefore, conformation of the hydrophobic chain in aggregates is infered to be more bending for UNDE. Changes of thermodynamic parameters in micellization and adsorption show smaller free energy reduction and larger increases in entropy and enthalpy for UNDE than those for UNDA.

The dependence of the scattered intensity on angles was measured by SAXS for a series of samples taken during the span process of the gelation of styrene with divinylbenzene. Based on these data. we obtained the fractal dimensions and their evolution for both sols and gels successfully.

Criegee intermediate is believed to play an important role in the atmospheric chemistry. Because of its short life and the difficulty in experimental study, we carried out ah initio calculations on the thermochemistry of the Criegee involving reactions in this study. Thermochemistry data of reaction enthalpies and Gibbs free energies for four different stable structures of the Criegee intermediates (singlet CH2OO ①1 A1 in C2v, triplet CH2OO ②3B1 in C2v, singlet CH2OO ③1A' in Cs and triplet CH2OO ④ in C1 symmetry) involved in some of the gas-phase reactions were calculated at the standard Gaussian-2 [G2(MP2) and G2] and a modified G2, G2(fu1)[10],levels of theory. Relative energies among those Criegees and formic acid were compared. Chemical reactions include the formation of Criegees, re-arrangement from Criegee to formic acid, dissociations (producing CH2(3B1)+O2, CH2(1A1)+O2, CO2+H2, CO2+2H, CO+H2O, OH+HCO) and the reactions between Criegee and NO/H2O. Standard equilibrium constants for some reactions were investigated and may be obtained for all of the rest reactions involved in this study by the standard Gibbs free energies. It is shown that the formation of Criegee ①-④ by ethylene and ozone, the re-arrangement from any Criegee to formic acid, the dissociation in producing CO2+O2and CO+H2O and the reactions between any Criegee and NO/H2O are all favourable thermodynamicaly. The dissociation in forming CO2+2H and OH+HCO is less favourable. While the dissociation in forming carbene (either in 3B1 or 1A1 state) is not allowed by ΔrGm? values. Standard enthalpies of formation at 298 K for the four Criegees were predicted at the G2(ful) level of theory. Each value is the average value from ten of the above reactions and they are -4.3, 74.8,98.9 and 244.6 kJ mol-1 at the G2(ful) level for Criegee ① to Criegee ④, respectively. In addition, tile standard enthalpy of formation at 298 K for HOCH2OOH is further predicted to be -315.6 kJ mol-1 at the G2(MP2) level.

Ab initio calculations have been performed for 6-X-2(1H)-pyridones (X=H, NH2, Cl,CH3, NO2) and their tautomers in the gas phase and in aqueous solution at HF/6-311G** level, the solvent effects were investigated with Onsager SCRF model. The substituent effects predicted by theoretical calculations are in satisfactory agreement with the experimental values, and the results obtained indicate the significance of solvent effects involved in this system.

Zeta potential of PC and PC-Cholesterol liposome was measured by microelectrophoretic mobility in the presence of different types of electrolyte. A combination of uy-Chapman-Stern theory and Poisson-Boltzmann equation was used to describe the regularity of the dependence of Zeta potential on several cations and anions with different valencies. Interaction mechanism of cation, anion and cholesterol with PC polar head group was discussed. The electrostatic force is dominated in influencing the surface potential of liposome.

The kinetics and mechanism of intramolecular condensation of amino ketones catalyzed respectively by six acids in methanol solution were studied by means of UV spectroscopy and 1H NMR.
The results indicate that the reaction proceeds with a general acid catalytic mechanism in the presence of acetic arid, and in lactic arid, in other stronger acids-methanol solution, the mechanism is of a special arid catalytic one. The result also shows that R2 has an effect on the reaction rate.

The interfacial instability due to the transfer of the 1-butanol from water to oil in two systems of 1-butanol oil/water has been studied. The dynamic characteristics of the phenomenon are investigated by analysing the motion of an oil lens deposited at the surface of the aqueous solution of 1-butanol. The interfacial adsorption kinetics based on diffusion-controlled transfer is analysed. It is found that the linear relation between the frequence of the oscillatory motion of the lens and t1/2 is a characteristic relation. The type of the solute transfer in the interfacial instability is discussed by comparing experimental results with the linear characteristics.