2000 Volume 16 Issue 12
A novel high-efficient photochromic self-assembly multilayered film has been fabricated from WO3 and 1,10-DAD solution using molecular deposition technique.The dependence of photochromic behavior on with WO3 in the WO3-polymer/1,10-DAD self-assembly film was discussed in comparison with WO3/4,4-BAMBp system.The results clearly show that organic molecules determine the charge density of the photo-induced charge-tracsfer complexes,andthus manipu-late the structure and the photochromic properties of the films.
Base on the analyses of the interaction between synthesis system materials and microwave field,the heating mechanism in the microwave field was studied.The heating rates of the synthesissystem were mainly determined by SrCO3 and TiO2 during low temperature range,and by TiO2 and SrTiO3 at high temperatures.The results show that the heating effects in microwave field are guite different from that in conventional furnace.The heating effect of the system in the microwave field which was influenced by several factors including dielectric properties of the synthesis's system and thermal insulate structures was discussed in detail.
The interaction between actin and cisplatin or transplatin hes been studied by using the 1H-NMR spectra and measuring the critical concentration of actin polymerization.These studies show that both cisplatin and transplatin induce a depolymerization of F-actin,and that the effect of transplatin is more obvious than that of cisplatin at the same concentration.It is found that cisplatin promotes a polymerization of G-actin at low concentration and inhibits it at high concentration.while transplatin inhibits the polymerization at any concentration.The binding sites of cisplatin/transplatin to G-actin are discussen.It is probable that cisplatin binds with Cys-10 and Cys-285,while tracsplatin does not bind with Cys-10.
The ab initio method atUHF/6-31G level is used to probe the reaction meaction mechanism of the elimination reaction of the addition radical formed by hydroxyl radical with Trichloroethylene and Perchloroethylene.The optimized transition state (TS) is tested by vibrational analysis,and the intrinsic reaction coordinate (IRC) calculations are performed.The reaction can proceed with eliminating a hydrogen chloride molecule to form an intermediate radical whose configuration is planar.The activation energy barrier is low,it is 79.84kJ mol-1 and 62.68kJ mol-1 respectively,both the elimination reactions under normal temperature and pressure are entropy increase,exothermal and Gibbs free energy ΔGΘ<Ο,that is,strongly spontaneous processes.
The coordination polymer of rare earth was prepared by the reaction of rare earth triisopropoxide(Pr,Nd,Eu) with electropolyurushiol polymerization(EPU).The structure and properties of the coordination polymer were characteized by FI-IR,Fluorescence,XPS,DMTA and AES.The results indicated that there is of coordination interaction between rare earth ion with electropolyurushilo in the coordination polymer,thus cross-link was formed.Therefore the coordination polymer was insoluble in most organic solvects,and glass.transition temperature increase and heat resistance were enhanced considerably.
Water-soluble poly(ethylene oxide)-block-poly(propylnen oxide)-block-poly-(ethylene oxide)(PEO-PPO-PEO) copolymers are nonionic macromolecular surface-active agents,available commercially as Pluronics.Recently,the micellization of these copolymers has been focused because of a strong interest in Pluronic micelles as drug-microcarriers in therapeutic creams and ointments.However, micellization of Pluroniccopolymers is very complex compared with those conventional surfactants.Due to this reason,interaction of binary Pluronic has been hardly studied up to now.This paper reported the micellization of binary Pluronic moleculesP94/L92 and F108/L92 which have similar length in PPO blocks and different length in PEO blocks,as well as P94/L64 which have different length in PPO blocks.I2 was used as a probe to determine the criticalmicelle concentration(cmc) of the mixtures in aqueous solutions.This method has been confirmed to be very sensitive to the determination of cmcm.The results showed that P94/L92 or F108/L92 binary components interact each other to form mixed micelles over the range of all concentration ratio.With addition of L92 molecules with a shorter PEO block,hydration of P94/L92 orF108/L92 mixed micelles was weakened duo to a decrease in the number of EO groups within the shell.When the mass fraction of L64,wL64<0.4,the micellization in P94/L64 mixtures was hindered and the cmc of P94 was enhanced to a higher value due to the formation of P94/L64 mixed pre-micelles in aqueous solution.Theses mixed pre-micelles have weaker hydrophobicity compared with those pre-micelles formed with individual P94 molecules.Over the range of wL64<0.4,therefore.there was only the micelles formed with individual P94 molecules when the micellization took place.With further increasing wL64,the mixed micelles of P94/L64 started to be formed and the critical point of mixed micelle formation was determined at wL64=0.4.
Negatively charged tetrasulfophthaloeyanines adsorb strongly on the surface of colloidal TiO2 through electrostatic interaction.In comparison with tetraalkoxy phthalocyanines,the interaction between tetrasulfophthaloeyanine and colloid TiO2 was probed by absorption and fluorometric spectroscopy and the apparent association constants K were calculated.Quenching of tetrasulfophthaloeyanine fluorescence by colloidal TiO2 is attributed to the charge injection from the excited singlet stste of tetrasulfophthaloeyanine to the conduction band of TiO2.The photoinduced electron transfer process was further elucidated by fluorescence lifetime measurements using single-photon counting technique.Tetrasulfopthalocyanines were adsorbed on the surface of nanocrystalline TiO2 electrode and their photoelectric properties were measured.It is indicated that the photoelectric response is closely related to the extent of association of tetrasulfophthalocyanines on the TiO2 electrode surface.
A new supermolecule coordination compound of perchlorate di(4-amino-1,2,4-triazole-5-one) silver(I) was synthesized.It was characterized by element analysis,FT-IR,X-ray crystallogram and single crystal diffraction.The titled complex was also studied by means of TG-DTG and DSC under conditions of linear trmperature increase.The thermal decomposition remainders were determined by infrared spectroscopic analysis.Thermal decomposition mechanism of the title coordination compound was suggested.
The reaction enthalpy of coordination reaction of lanthanum chloride with Glycine is determined by solution calorimetry in an isoperibel reaction calorimeter.The calormetric solvent is the solution of hydrochloric acid (2 mol L-1),a new thermochemical cycle is designed.According to the results,the following date: ΔrHΘm(298.2K)=-4.310kJ mol-1 ΔrHΘm(La(Gly)3Cl3 5H2O,s,298.2K)=-4222.93kJ mol-1 were obtained.
Solubilities of ammonium tetraphenylborate (NH4BPh4) in water-t-butyl alcohol (TBA) mixed solvents at 283.15,293.15,298.15,303.15 and 308.15K have been determined by spectrophotometry.The standard Gibbs energy of transfer (ΔGΘt) of NH4BPh4 from water to H2)-TBA mixtures and the primary medium effect of NH4BPh4 from 283.15 to 308.15K were studied.The results show that-ΔGΘt exhibits a complicated variation pattern with the increase in the mole fraction of TBA [x(TBA)] at the same temperature.When x(TBA)<0.06,-ΔGΘt increases very slowly with x(TBA),the-ΔGΘt increases rapidly with x(TBA) when x(TBA) from 0.06 to 0.2.For x(TBA)>0.2,the -ΔGΘtdecreases with increasing x(TBA).The largest value of -ΔGΘt occurs at x(TBA)=0.2.The main reason for this variation was analyzed and discussen.