摘要:

Abstractn‐Hexadecanoic acid (HA) and α‐hydroxyln‐hexadecanoic add (HHA) are shown to spontaneously assemble on Si‐supported titanium surfaces. Contact angle measurements, reflection absorbance IR, AFM and XPS characterizations are performed to examine the physical and chemical states of attached monolayers. The results show that the two amphiphiles tend to form disordered monolayers on titanium surfaces. The HHA headgroups are believed to form polydentate coordination with Ti, which is more chemically stable than the bidentate coordination of HA. All the facts of characterization indicate that HHA monolayer has more surface coverage than HA m

ISSN:1001-604X    

DOI:10.1002/cjoc.20020201202

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2002

数据来源: WILEY

摘要:

AbstractA novel supramolecular complex {[Cu(n)(en)2·H2O]·[Cu(I)2(CN)4]}n(en = ethylenediamine), in which the cyanide‐bridged Cu(I) forms the honeycomb‐like skeleton host and the Cu(n) complex ion [Cu(en)2·H2O]2+is encapsulated in the center of the channel cavity of the skeleton, was synthesized by two different methods. The complex was also characterized by elemental analysis, ICP analysis, IR spectra and thermal analysis. The adsorption and desorption studies of the complex indicate that H2O and NH3can be desorbed and re‐adsorbed without collapse of the channel structure of the supra

ISSN:1001-604X    

DOI:10.1002/cjoc.20020201203

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2002

数据来源: WILEY

摘要:

AbstractThe benzylation and allylation of 4‐nitrobenzaldehyde (1) could be controlled chemoselectively by using different phase transfer catalyst (FTC) and different metal catalysts. And then, benzylation and allylation of 1 with various organic halides has been realized in high yields in aqueous medi

ISSN:1001-604X    

DOI:10.1002/cjoc.20020201204

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2002

数据来源: WILEY

摘要:

AbstractWith the aid of wind‐tunnel experimental setup, the possibilities that nitrogen monoxide (NO) is oxidized to nitrogen dioxide (NO2) in various environments were studied, which include indoor, outdoor and darkroom conditions. By comparing their effects, a conclusion can be drawn that NO can be oxidized to NO2in indoor environment with a low rate, and micro amount of ozone, propylene and methane can accelerate the reaction: 2NO+ O2·NO2. The initial concentration of NO has effect on the oxidation rate. When the initial concentration of NO ranges between 500 and 900 μg/L, natural logarithm of initial rate and natural logarithm of initial concentration have a good linear relation, so do m(1/[NO]) and the time (t). Besides mat, the possible oxidation mechanism of indoor NO has also been stud

ISSN:1001-604X    

DOI:10.1002/cjoc.20020201205

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2002

数据来源: WILEY

摘要:

AbstractThe singlet and triplet potential energy surfaces of interstellar molecule C,S are predicted at the UB3LYP/6–311 (d) and UCCSD(T)/6–311 + G(2df) (single‐point) levels. The linear singlet isomer CCCS with1Σ+electronic state is found to be thermodynamically and kinetically the most stable species on the singlet surface followed by other four singlet isomers, which are unstable on the basis of calculated results. On the triplet surface, the lowest‐lying species, which lies 248.79 kJ/mol above linear singlet species CCCS, is chain CCCS connectivity with3A' electronic state. Other four triplet isomers can be considered as unstable species by means of transition state and potential energy surface scan technologies. The structures, vibrational frequencies, dipole moments and rotational constants of all optimized species are also ca

ISSN:1001-604X    

DOI:10.1002/cjoc.20020201206

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2002

数据来源: WILEY

摘要:

AbstractThe thermal behavior, mechanism and kinetic parameters of the exothermic first‐stage decomposition reaction of the title compound in a temperature‐programmed mode have been investigated by means of DSC, TG‐DTG and IR. The reaction mechanism was proposed. The empirical kinetic model functions in differential form, apparent activation energy (Ea) and pre‐exponential factor (A) of this reaction are (1 ‐ α)−1.119, 211.3 kj/mol and 1020.2s−1, respectively. The critical temperature of thermal explosion of the compound is 202.2 °C. The values of ΔS≠, ΔH≠and CΔG≠of this reaction are 143.8 J.mol−1.K−1, 208.7 kj/mol an

ISSN:1001-604X    

DOI:10.1002/cjoc.20020201207

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2002

数据来源: WILEY

摘要:

AbstractThe extraction behaviors ofL‐phenylalanine by di‐(2,4,4‐trimethylpentyl) phosphinic acid, di‐(2,4,4‐trimethylpentyl)‐monothiophosphinic acid and di‐(2‐ethylhexyl) phosphoric acid were studied in both two‐phase and three‐phase systems respectively. The equilibrium constants for these extraction reacti

ISSN:1001-604X    

DOI:10.1002/cjoc.20020201208

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2002

数据来源: WILEY

摘要:

AbstractThe effects of activator molecule and repressive molecule on binding process between allosteric enzyme and substrate are discussed by considering the heterotropic effect of the regulating molecule that binds to allosteric enzyme. A model of allosteric enzyme with heterotropic effect is presented. The cooperativity and anticooperativity in the regulation process are studied.

ISSN:1001-604X    

DOI:10.1002/cjoc.20020201209

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2002

数据来源: WILEY

摘要:

AbstractBy employing electrostatic interaction as driving force, an organic/inorganic composite with positively charged dimethyl dialkyl‐chain ammonium surfactants encapsulating negatively charged (NH4)12[Mo36(NO)4O108(H2O)16]. 33H2O polyoxoanion was prepared. The structure of the novel organic/inorganic hybrid particle with hydrophilic core and hydrophobic shell in a defined stoichiometric ratio was confirmed by element analysis,1H NMR and FT‐IR spectra. The property of the polyoxoanion was changed due to the encapsulation and it can be dissolved in organic solvent such as chloroform, benzene and toluene, but not dissolved in wa

ISSN:1001-604X    

DOI:10.1002/cjoc.20020201210

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2002

数据来源: WILEY

摘要:

AbstractA new magnesium borate MgO·B2O3·4H2O was synthesized by the method of phase transformation of double salt and characterized by XRD, IR spectra and TG. The structural formula of this compound was Mg·[B2O(OH)6]·H2O. The enthalpy of solution of MgO·B2O3·4H2O in HCl (1.0492 mol·L−1) was determined. With the incorporation of the standard molar enthalpies of formation of MgO (s), H3BO3(s), and H2O (1), the standard molar enthalpy of formation of ‐ (3135.31 ± 1.68) kJ·mol−1of MgO·B2O3·4B2O was obtained. Thermodynamic properties of this compound were also calculated by group con

ISSN:1001-604X    

DOI:10.1002/cjoc.20020201211

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2002

数据来源: WILEY