EFFECTS OF TRITON X-100 ON BELOUSOV-ZHABOTINSKY REACTIONS

The effects of Triton X-100(TX100),a nonionic surfactant,on Belousov-Zhabotinsky reactions(B-Z reactions),including H_2SO_4~+ malonicacid(MA)+KBrOs+Mn~(2+)and H_2SO_4+gallic acid(GA)+KBrO_3 systems,havebeen investigated.The results showed that the oscillation parameters(theinduction period,average oscillation period,oscillation lasting time)inthese B-Z reactions were changed suddenly near the critical micelle concen-tration(CMC)of TX100.The results were explained according to the mechanismof B-Z reaction and the properties of micelles of the surfactant.     

DIFFERENT EFFECTS OF ENANTIOMERS OF TETRAHYDROPALMATINE ON DOPAMINERGIC SYSTEM

Tetrahydropalmatine (THP) has two enantiomers with different effects on the brain dopaminergic system. Using [~3H]spiperone for DA receptor binding assay, it was found that l-THP had an affinity to DA receptors (K_1=0.2μM). Neither d-THP nor reserpine showed such an effect even at concentrations higher than 100 or 1000μM. Based on the fact that the presynaptic DA receptors take part in feed-back regulation on tyrosiue hydroxylase activity, DOPA accumulation could be observed in rat striatum after injection of benserazide. A small dose of l-THP (2.5, 5, 10 mg/kg, ip.) caused an elevation of DOPA level by 49—282% versus the control value, and could reverse the decrease of DOPA level induced by apomorphine, a DA receptor agonist. On the contrary, d-THP displayed a biphasic effect on DOPA level, slight decrement (26—37%) at 10 and 25mg/kg, naught at 50mg/kg, and a 91% increment at 100 mk/kg, which was less than that of l-THP at 5mg/kg. Moreover, measured by pulse voltammetry, DOPAC level in the striatum     

ADSORPTION OF PHENOL IN NON—AQUEOUS SYSTEM BASED ON HYDROGEN—BONDING

Two hydrogen-bonding adsorbents-macroporous crosslinked poly(P-nitrostyrene)and poly(p-vinylbenzyl amide)-were synthesized,and the adsorption property of phenol from cyclohexane solution onto the adsorbents was studied,The differential adsorption heasts for varied adsorption capacities calculated from the adsorption isotherms according to the Claperyron-Clausius equation lay in the range of hydrogen bond energy (8-50kJ/mol),The adsorption capaccity of o-nitrophenol in cyclohexane was moch less than that of phenol under the same condition.The adsorption capacity of phenol from cyclohexane onto polyacrylonitrile was much less than that onto poly(p-nitrostyrene)or poly(p-vinylbenzyl amide),All these results revealed that adsorption of phenol from cyclohexane by poly(p-nitrostyrene) or poly(p-vinylbenzyl amide)is based on hydrogen-bonding.     

ELECTROCARBOXYLATION OF ORGANIC COMPOUNDS WITH CARBON DIOXIDE CATALYZED BY METALLOPORPHYRINS(Ⅲ)——EFFECTS OF AXIAL LIGANDS ON CATALYTIC ACTIVITY OF CoTPP

The effects of peptides,amino acids and organic bases as an axial ligand on reaction ac-tivities in the electrocarboxylation of benzyl chloride with CO_2 catalyzed by CoTPP are reported.The imidazole organic base,peptide containing —SH and amino acid containing imidazolyl en-hance the catalytic activity.The effect of imidazole amounts on the catalytic activity of CoTPP isstudied.     

MULTIDENTATE LIGAND EXCHANGE KINETICS: REACTIONS OF AMINOCARBOXYLATO-FERRATE(Ⅲ) COMPLEXES WITH 4-(2-PYRIDYLAZO) RESORCINOL

The kinetics and mechanism of ligand substitution reactions of nitrilotriacetatoiron(Ⅲ), [Fe(NTA)], and N-(2-hydroxyethyl)-ethylenediaminetfiacetatoiron(Ⅲ), [Fe(HEDTA)], complexes with 4-(2-pyridylazo) resorcinol (Par) has been investigated at pH = 9.0±0.02, I= 0.1mol·1~(-1) (NaClO_4), and temp. = 25 ±0.1℃ and 30±0.1℃ respectively. The reaction has been studied spectrophotometrically at 496 nm. (λ_(max) of Fe(Par)_2). In both reactions the final product was [Fe(Par)_2]~-. The values of second order rate constants for NTA and HEDTA exchange reactions are (10.0±0.8)×10~1·mol~(-1)·s~(-1) and (2.7± 0.1)×10~(-1) 1·mol~(-1)·s~(-1) respectively. The reactions of NTA and HEDTA exchange were studied in the pH range 6-9.5 and 7-10.85 respectively. The rate of reacton of [Fe(NTA)] with HPar~- first increases with pH and then levels off. However, in the case of [Fe(HEDTA)] reaction, the rate increases monotonically with increase of pH in the specified range. The reverse reactions between [Fe(Par)_2     

MULTIDENTATE LIGAND EXCHANGE KINETICS:REACTIONS OF AMINOCARBOXYLATO-FERRATE(Ⅲ) COMPLEXES WITH 4-(2-PYRIDYLAZO) RESORCINOL

The kinetics and mechanism of ligand substitution reactions of nitnlotriacetatoiron(Ⅲ),(Fe(NTA)],and N-(2-hydroxycthyl)-ethylencdiaminetriacetatoiron(Ⅲ),[Fe(HEDTA)],complexes with 4-(2-pyridylazo) resorcinol (Par) has been investigated at pH=9.0±0.02,I=0.1mol·l^-1 (NaClO₄,and temp.=25±0.1℃ and 30±0.1℃ respectively. The reaction has been studied spectrophotometrically at 496 nm. (λmax of Fe(Par)₂. In both reactions the final product was [Fe(Par)₂]^-. The values of second order rate constants for NTA and HEDTA exchange reactions are (10.0±0.8)×10¹¹·mol^-1·s^-1 and (2.7±0.1)×10^-1·mol^-1·s_-1 respectively. The reactions of NTA and HEDTA exchange were studied in the pH range 6-9.5 and 7-10.85 respectively. The rate of reacton of [Fe(NTA)] with HPar^- first increases with pH and then levels off. However,in the case of [Fe(HEDTA)] reaction,the rate increases monotonically with increase of pH in the specified range.     

STUDIES ON THE VOLTAMMETRIC BEHAVIOR OF EU(Ⅲ)-ALDOPENTOSE AND EU(Ⅲ)-D-RIBOSE-L-AMINO ACIDS COMPLEXES

The rate of voltammetric reduction of Eu(Ⅲ)in acetate solutionwas increased by the formation of a complex with ribose,lyxose orarabinose.If a ternary complex of Eu(Ⅲ)-D-ribose-L-phenylanaline formed onthe surface of mercury electrode,the redox process of Eu(Ⅲ)became morereversible than that of Eu(Ⅲ)-D-ribose in solution phase.     

EFFECTS OF CONFORMATION OF POLYMER LIGANDS IN COPPER(Ⅱ) COMPLEXES ON CATALYLIC ACTIVITIES AND MECHANISM OF OXIDATIVE COUPLING OF β-NAPHTHOL

Copper(Ⅱ) complexes of sericin, chitosan, 6-and 2-aminodeoxystarch were used as catalysts in oxidative coupling of β-naphthol, the effects of conformation of the polymer ligands in these complexes on activities of the catalysts and mechanisms of the reaction were studied. It was found that if the catalysts react with the substrate by mechanism similar to the enzymic catalysis they must be composed of polymer ligands with highly coiled, especially with densely helicoidal, conformations. While catalysts composed of loosely coiled or helicoidal hgands react with the substrate through molecular collision and have relatively lower activities only. Under nitrogen, catalysts from sericin and chitosam reacting with β-naphthol give optically active β-binaphthol, rotating polarized light to right, but the stereoselectivities are rather low.     

A HIGHLY EFFICIENT SYNTHESIS OF(5,10,15,20-TETRAPHENYLPORPHYRINATO)GALLIUM(Ⅲ)ACETATE

(TPP)OAc was obtained by refluxing Ga_2O_3 and the free base TPPH_2 in aceticacid containing sodium acetate in a yield of 65%.     

HYDROXYLATION OF n-HEXANE CATALYZED BY SUPPORTED Mn (Ⅲ)—PORPHYRIN COMPLEXES

Water-soluble Mn (Ⅲ)-porphyrins supported on various carriers as monooxygenase—like catalysts were used for n—Hexane hydroxylation by PhIO. The hydroxylation yields and XPS measurement of the catalysts indicate that the carriers containing—OH groups have favorable steric and electronic effect on Mn—porphyrins. Some influencing factors and the role of carriers are discussed.     

STUDIES ON THE ACTIVITY COEFFICIENTS OF NON-ELECTROLYES IN AQUEOUS SALT SOLUTIONS Ⅲ. THR EFFECTS OF SALTS OF FATTY ACIDS ON THE SOLUBILITIES OF CAPROIC ACID IN WATER

The solubilities of caproic acid in aqueous solutions of sodium salts of fivefatty acids (C_1 to C_5) have been measured at 25℃. All these salts increase thesolubilities of caproic acid. The reason for salting-in is due to partial displacement of the salt by thecaproic acid producing a new acid. But the new acid may distribute itself betweenthe aqueous salt, solution phase and the caproic acid phase thus rendering the actualsolubilities less than the calculated values.     

STUDIES ON STRUCTURAL-OPTICAL MINERALOGY——EFFECTS OF ELECTRON

In this paper, the Gladstone-Dale ionic refractivities (GDIR values) are calculated onthe basis of the K values given by Mandarino and/or the author. The effects of the elec-tron shell configuration of ions on the refractive properties of minerals are discussed. Theconclusions are as follows: (1) The refractive indices of the compounds consisting of Ne-type ions are linearlyrelated with their densities. (2) The ionic refractivities of the inert gas-type ions are different from those of 18electron-type ions in their variation relationship. (3) The ionic refractivities of ⅠA, ⅡA, ⅢA, ⅣA, ⅤA and ⅥA Groups in the periodictable increase linearly with increasing atomic number. (4) The two-humped curves are found for the ionic refractivities of the first transitionelements. (5) Because of the lanthanum series contraction, the ionic refractivities of rare earthelements decrease with increasing atomic number.     

THE STATE OF CHROMIUM (Ⅲ) ION IN AQUEOUS SOLUTION

So far few systematic studies on the hydrolytic polymerization of Cr(Ⅲ) were reported because of inertness of the ion and complication of the process. We studied it in equilibrium by pH method systematically in a wide concentration range (0.0002—0.32 M). The results show that, in the low concentration range, the composition of the polynuclear hydrolysis products may be represented as [Cr_3(OH)_4] (OH)_n (n=1,2,3); in the medium range, the composition of products as Cr[Cr(OH)_2]_n~((3+n))~+ (n=1,2,3); in the high range, the composition of products as Cr[Gr(OH)]_n~((3+2n))~+ (n=1, 2), and in the intermediate range between medium and high range where the hydrolysis system is in a transition state, the composition of products as [Cr_3(OH)_3]~(6+) and [Cr_3(OH)_4]~(5+). The values of hydrolysis constants of the identical species measured in different Cr concentration ranges and calculated by different methods were found in good agreement with each other. A predominance-arca diagram was made by using the hy     

STUDIES ON THE REACTION MECHANISM OF ORGANIC HYDROPEROXIDE AND AMINE SYSTEM INITIATED POLYMERIZATION

The initiation mechanism of organic hydroperoxide and amine system has been investigatedsystematically in this paper. It has been confirmed from the IR spectra that organic hydro-peroxide could form hydrogen-bonded complex with amine. The reactive intermediate of theamine and its effect on initiating polymerization have been determined by using ESR techni-que, and further proved by the results of polymer end group analysis and graft copolymeri-zation of vinly monomer onto the amino-containig polymer. Finally, water, as one of the finalproducts of ROOH-amine reaction has been detected through chromatographic analysis, fromwhich the conversion reaction of the reactive intermediate is verified.     

EFFECTS OF SOURCE PROPERTIES ON CUTOFF FREQUENCY f_(max)

The cutoff frequency f_(max) of radiation from earthquakes is one of the important parameters for studying the source process. By theoretical analysis and numerical experiments on acceleration Fourier spectrum it is suggested that f_(max) mainly depends on the lower values of slip rise time. This result can be used to explain the observational fact that the greater the earthquake magnitude, the smaller the value of f_(max).     

KINETIC AND APPLICATION: STUDIES ON THE REACTION SYSTEM OF OSMIUM(Ⅳ)-ARSENIC(Ⅲ)-CHLORATE

The experiments have proved that Os(Ⅳ) has very strong catalytic effect on the chlorate oxidation of As(Ⅲ) in perchloric acid media, and As(Ⅲ) exhibits a sensitive single-sweep oscillopolarographic wave at-0.75 V vs. SCE. The kinetics of this catalytic reaction has been investigated by the initial rate procedure. The mechanism has been proposed. A new and highly sensitive catalytic reaction-oscillopolarographic method for the determination of ultratrace amounts of osmium has been described, based on the Os(Ⅳ) catalytic effect on the reaction. The linear range of 5.0×10~(-11)-4.4×10~(-9) mol/L and 6.0×10~(-9)-1.3×10~(-7) mol/L Os was obtained using the fixed-time procedure and the initial rate procedure, respectively. Osmium in refined ore was analysed by this method.     

STUDIES ON ELECTROANALYTICAL CHEMISTRY OF RARE EARTH ELEMENTS——POLAROGRAPHIC INVESTIGATION OF CARBOXYNITRAZO (CNA) AS A LIGAND OF RE-CNA COMPLEXES

The polarographic behaviour of carboxynitrazo (CNA) has been investigated in detail by means of single-sweep, DC, AC polarography and cyclic voltammetry. It has been shown that CNA has different reduction mechanisms in acidic and basic solutions. In acidic solution, the first wave is reversible and the second involves the disproportionation mechanism with acid catalysis, while in basic solution the first wave splits into two and the second wave has no disproportionation characteristics. The third wave is the reduction of nitro-group in the molecule.     

STUDIES ON THE ACTIVITY COEFFICIENTS OF NONELECTROLYTES IN AQUEOUS SALT SOLUTIONS——Ⅱ. THE EFFECTS OF SALTS OF FATTY ACIDS AND QUATERNARY AMMONIUM SALTS ON THE SOLUBILITIES OF NAPHTHALENE IN WATER

On the assumption that the salt effect (salting-out or salting-in) representsthe balance of the electrostatic effect between the ion and the water dipole andthe dispersion effect between ion and nonelectrolyte molecule, the solubilitiesof n-valeric acid in five cobaltammimes were studied and reported in article Ⅰof this series. In the present investigation the activity coefficients of naph-thalene in two series of salts are determined spectrophotometrically. The firstseries consists of seven sodium salts of fatty acids (sodium formate to sodiumn-heptylate), differing from one another only by the number of CH_2 groups inthe anions. The second series consists of ammonium bromide and three tetra-     

MONTE CARLO SIMULATION ON AQUEOUS SOLUTION OF BIOLOGICAL MOLECULES——ALANINE SOLUTION

The Monte Carlo simulation is performed for a cluster consisting of a neutral alanine molecule surrounded by 56 water molecules. The average water-water and alanine-water interaction energies are found. The space surrounding the alanine molecule is divided into three regions, where the central atoms are C' atom for the earboxyl group region, N atom for the amino group region and C~β atom for the methyl group region. The water-water and water-alanine interaction energies as functions of the distance between the oxygen atom in a water molecule and the central atom in each region are calculated. In each region the orientational correlation function for the dipole moments of water molecules, the radial distribution function for the oxygen and hydrogen atoms of water molecules are evaluated. In addition, the numbers of water molecules in the first solvation shells of each region and of entire alanine molecule are also counted.     

EFFECTS OF SYNTHESIS PARAMETERS ON ZEOLITE ZSM-48 IN A SOLID REACTION MIXTURE SYSTEM

IntroduCtionReCently,zcoliteZSM-48hasbeenspehesizedinapurelysolidsystemll1.Thismethedusedtosynthesizezcolitescangndlyincreasetheyieldofpnductsperunitvolume,simplifythepr0cedresanddecreasethecnvironmentalpolluti0n.ThisincreasestheacualPOssibilityofsynthesisofhigh-silicazcolitesinchemicalindustry.MoreOver,itisalsohelpfulforstUdyingthezeolitecrystalliZai0nmechanism.ItiswellknownthatthesamewneofzeolitessynthesizedindifferentsystemshasdifferentcatalyticpropertiesduetothechangesoftheirfinestruC…