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.     

INFLUENCE OF THERMAL AND NON—THERMAL EFFECTS OF ULTRASOUND ON ISOTHERMS OF PHENOL ON NKAⅡ RESIN

Adsorption equilibrium experiments of phenol on the NKA II resin are separately conducted in the presence and absence of ultrasound at ambient temperature.The isotherm of phenol on the polymer adsorbent in the presence of ultrasonic field is firstly reported.Results indicated that the isotherm of phenol determined in the presence of ultrasound is lower than that in the absence of ultrasound.In addition,experiments also show that the use of ultrasound to the adsorption system of the phenol aqueous solution and NKA Ⅱ resin could cause the rising of the temperature of the system in the order of 6^-C.The effect of ultrasound on the isotherm of the phenol on the NKA Ⅱ resin mostly ascribes to the thermal effect and the non-thermal effect of ultrasonic field.and the role of the later is greater than that of the former.     

NORMAL COORDINATE TREATMENT OF COMPLEXES OF LANTHANIDE NITRATES WITH CROWN ETHER

In this paper, by using point mass model, the normal coordinate lanalysis calculations of La(15-C-5) (NO_3~-)_3 and La (18-C-6) (NO_3~-)_3 are performed to give theoretical results in agreement with frequencies and intensities of infrared and Raman bands. In the calculations, the same force constants with respect to the two molecules are adopted and some internal coordinates which are less important are neglected. Furthermore, the properties of coordination bonds, approximation calculation method and other related problems are discussed.     

Determination of Metamizole Sodium by Cyclic Voltammetry Under Microwave Activation

<正>Microwave radiation was applied to the detection of metamizoie sodium by cyclic voltammetry.The electrochemical characteristics of metamizoie sodium were studied by cyclic voltammetry at GC electrode under microwave radiation and a considerable current enhancement was observed for metamizoie sodium in aqueous 0.05 mol/L H_2SO_4.Under the optional conditions,metamizoie sodium was determined in the absence and presence of microwave activation.In the absence of microwave activation cyclic voltammogram of metamizoie sodium shows good linear relationship in a concentration range of 8.0×10~(-5)—1.0×10~(-3) mol/L in aqueous 0.05 mol/L H_2SO_4 with a detection limit of 6.75×10~(-6) mol/L(S/N=3) and the equation of linear regression is I_p=12.973c-0.1905(R~2=0.9996,n=6);in the presence of 80 W microwave activation cyclic voltammogram of metamizoie sodiumin shows good linear relationship in a concentration range of 4.0×10~(-5)—1.0×10~(-3) mol/L in aqueous 0.05 mol/L H_2SO_4 with a detection limit of 4.41×10~(-6)mol/L(S/N=3) and the equation of linear regression is I_p=25.107c-0.1193(R~2=0.9973,n=7).The current in the presence of 80 W microwave activation increases to about 2 orders of magnitude compared with that in the absence of microwave activation.The proposed method in the presence of microwave activation showed high selectivity and sensitivity,and the sampling of the disposal method is simple.The method was verified by the determination of Metamizoie Sodium tablet with satisfactory results.     

OXIDATIVE COUPLING OF METHANE OVER SrO-La_2O_3/CaO CATALYSTS Ⅲ.THE REACTION MECHANISM

In the previous kinetics study,we found that there are differencesin the reaction behavior and the pathway of CO_x formation between the LC andSLC Catalysts.In this paper,several mechanisms have been tested.It is con-firmed that the oxidative coupling of methane over the LC follows bangmuir-Hinshelwood mechanism and an adspecies of oxyen in its molecular form(O_2) is the active species.While the reaction over the SLC catalyst follows amodified Rideal-Redox mechanism and an adspecies of oxygen in its atomicform (O~-) is the active species.     

STUDIES ON THE SYMMETRY OF QUATERNARY STRUCTURE OF PHOSPHOENOLPYRUVATE CARBOXYLASE FROM SORGHUM LEAVES

Studies on the symmetry of quaternary structure of PEP carboxylase from sorghum leaves were carried out by means of chemical crosslinking with bifunctional reagents (diimidoesters) and subsequent SDS polyacrylamide gel electrophoresis.Results showed that the four identical subunits of the enzyme are associated isologously: i.e. the quaternary structure of the enzyme has a D_2 symmetry.The patterns of PEP carboxylase crosslinked with suberic dimethylimidate varied in the presence of various ligands.Substrate PEP, Mg~(2+) (required for catalysis of the enzyme), PEP plus Mg~(2+) and the inhibitor malate increased the extent of crosslinking of the enzyme in varying degrees, indicating that binding of these ligands to the enzyme gave rise to changes in the subunit interactions.However,the extent of crosslinking of PEP carboxylase with suberic dimethylimidate decreased greatly in the presence of the activator G6P. Meanwhile, the enzyme remains a tetrameric form either in the absence or in the presence of G6P.     

KINETICS OF POLYMERIZATION OF ACRYLONITRILE INITIATED BY VANADIUM(V)-THIOUREA REDOX SYSTEM

The kinetics of polymerization of acrylonitrile (AN) initiated by quinquevalent vanadium (V~(5+))-thiourea (TU) redox system has been investigated in aqueous nitric acid in the temperature range from 30 to 50℃. The polymerization rate (R_p) can be expressed as follows: In the copolymerization of acryionitrile with methyl acrylate (MA), the reactivity ratios were found to be 1.0 and 1.1, respectively. The experimental observations suggest that the initiating species is probably a complex consisting of a central ion of Lewis acid-VO_2~+ and the ligands of Lewis bases-acrylonitrile, thiourea, and nitrate anions, while the initiating system in lower concentration, the polymerization of acrylonitrile does not occur if the thiourea is acidified prior to its reaction with quinquevalent vanadium. This indicates that the primary radicals (or the monomeric radicals in the present article) are produced by associated thiourea rather than isothlourea.     

THE EFFECTS OF IRRADIATION ON THE THERMAL PROPERTIES OF SEMI-CRYSTALLINE POLYAMIDES

Irradiation crosslinking of semi-crystalline polyamides was performed by high energy electronswith various dosages. It is known that the melting behavior of the polymers after irradiation is acomplex phenomenon. In company with the wide angle X-ray diffraction and DSC data of irradiatedand unirradiated polyamides it is possible to develop the local order and perfection of the crystallinitiesslightly which resulted from introduction of intermolecular crosslinking in amorphous region, incl-uding in amorphous-crystalline interface and crystalline defect regions due to irradiation. It canbe explained that slight increase of melting temperature (T_m) and heat of fusion (△H_f) with increasingdosage for both of higher crystallinity nylon 4 and nylon 6. For irradiated lower crystallinity nylons,in contrast, the T_m and △H_f decrease obviously with increasing dosage. In this case, radiation cross-linking "freeze in" the pre-existing morphology, and then the prevention for reorganization duringheating is a dominant effect. The T_m from the second melting for all of the samples were depressed,corresponding with Flory theory. Therefore the crosslinks imposed on the molecules restrainedthe molecular mobility, and that not only depresses the crystallinity but also increases the imperfec-tion of crystallites when the radiated polymer melted and then recrystallized. These are also reflectedin the depression of heat and entropy of fusion as well as the appearance of double melting peakson the DSC thermograms.     

Mn(Ⅱ)和Ce(Ⅳ)离子对铬酸氧化乳酸的影响

The kinetics and mechanism of lactic acid oxidation in the presence of Mn(II)and Ce(IV)ions by chromic acid were studied spectrophotometrically.The oxidation of lactic acid by Cr(VI)was found to proceed in two measurable steps,both of which gave pyruvic acid as the primary product in the absence of Mn(II).2Cr(VI) 2CH3CHOHCOOH→2CH3COCOOH Cr(V) Cr(III)Cr(V) CH3CHOHCOOH→Cr(III) CH3COCOOH The observed kinetics was explained due to the catalytic and inhibitory effects of Mn(II)and Ce(IV)on the lactic acid oxidation by Cr(VI).The reactivity of lactic acid depends upon the experimental conditions.It acts as a two-or three-equivalent reducing agent in the absence or presence of Mn(II).It was examined that Cr(III)products resulting from the direct reduction of Cr(VI)by three-equivalent reducing agents.The oxidation of lactic acid follows the complex order kinetics with respect to [lactic acid].The activation parameters Ea,ΔH#,and ΔS# were calculated and discussed.     

THE MECHANISM OF COPOLYMERIZATION OF VINYL AND DIVINYL MONOMER Ⅵ: A STUDY ON THE MECHANISM OF THE STRUCTURE FORMATION OF CROSSLINKED POLYSTYRENE

In order to study the mechanism of the formation of maeroporous copolymer, the overall reaction kinetics, phase separation and gelation of the S/EGDM in the presence of inert solvents and the physical properties of the eopolymer were investigated and compared with the corresponding system of S/DVB and S/DVB/MMA. The formation of the network structure of the macroreticular polymer was studied and a model of the mechanism suggested.     

STUDIES ON CHIRAL THIOPHOSPHORIC ACIDS AND THEIR DERIVATIVES——STEREOCHEMISTRY OF ALKALINE HYDROLYSIS OF OPTICALLY ACTIVE O-ETHYL O-PHENYL PHOSPHOROTHIOIC DERIVATIVES

The reaction of optically active O-ethyl O-phenyl phosphorochloride 1 with alcohol, phenol,amine, mercaptan or thiophenol, respectively, in the presence of an alkali obtained optically activeO-ethyl O-phenyl phosphorothioic derivatives 2 with inversion of configuration. The hydrolysis of 2was carried out in 1 N NaOH-dioxane solution. The hydrolysis of 2a and 2h predominantly gaveproducts with inversion of configuration with OPh as leaving group, but also gave products withretention of configuration with OMe or SPr as leaving group. Exclusive products with inversion ofconfiguration with OPh as leaving group were only obtained from the hydrolysis of 2b, 2f and 2g.The hydrolysis of 2c gave product with inversion of configuration with OC_6H_4NO_2-p as leavinggroup. From 2d, 2e and 2i, products with retention of configuration were formed with OC (Me)-CHCO_2 Et(Z), OC(Me)-CHCO_2Et(E) and SPh as leaving group, respectively. All the above resultscan be satisfactorily interpreted in the light of trigonal bipyram     

THE EFFECTS OF SOLVENTS ON THE INTRAMOLECULAR PROCESSES ——NMR STUDY

The influences of methanol-d_4(MeOD), dimethylsulfoxide-d_6 (Me_2SO(D)) and dioxane(C_4H_8O_2) solvents on the intramolecular processes are studied by NMR. It has been shown that the addition of these solvents in CdEGTA complex aqueous solution can increase the rate constant (k) of the nitrogen inversion and decrease the activation energy of this process. The linear relations between In(k) and the reciprocal of the solvent dielectric constants (1/ε) are obtained for all the three solvents.     

STUDIES ON CHIRAL THIOPHOSPHORIC ACIDS AND THEIR DERIVATIVES [ⅤⅢ]——THE STEREOCHEMISTRY OF SOME REACTIONS OF THE MIXED ANHYDRIDE OF O-ETHYL PHENYLPHOSPHONOTHIOIC AND O-ETHYL O-PHENYL PHOSPHOROTHIOIC ACIDS

In this paper, (1) alkaline methanolysis, (2) acid methanolysis, (3) alkaline hydro-lysis, (4) aminolysis of (+)-(R)-(R)-mixed anhydride 1 of O-ethyl phenylphosphonothioic:and O-ethyl O-phenylphosphorothioic acid, (5) its reactions with KSH and (6) with PCl_5have been studied. The cleavage of P-O-P bonds in all the reactions studied has beenfound. In reactions (1)-(4), attacks of nucleophiles occur to the phosphorus atoms of phos-phonyl groups forming the products with inversion of configuration, while the configurationof the phosphorus atoms of phosphoryl groups which are not attacked is retained. Inreaction (5), the uncleophile -SH attacks the phosphorus atom of the phosphonyl group,but a racemic product results because of the formation of ph(EtO)P(S)~- which loseschirality; the configuration of the phosphorus atom of the phosphoryl group which is notattacked is still retained. In reaction (6), both the phosphonyl and phosphoryl groups arechlorinated giving as products (-)-(R)-thiophophonyl chloride 1     

THE EFFECTS OF SUPPRESSIVE ACTIVITIES MEDIATED BY CELLS ON THE PROTECTION OF FETUS AGAINST MATERNAL IMMUNE REJECTION

Using both mixed lymphocyte reaction (MLR) and graft-versus-host reaction (GVHR) assays, investigations have been made on 60 multiparous mice of late pregnancy, derived from C57BL mating with SWI as well as C57BL mating with BGI. The results demonatrate the presence of suppressor cells both in uterus-draining-lymphnodes (DLN) and in spleen of allogeneie pregnant mice. The suppressive immune regulatory activity mediated by these cells might play an important role in the successful maintenance of fetus allograft. The possible mechanisms about the inducing of the changes in lymphocyte subpopulation are also studied in this paper.     

THE CRYSTAL STRUCTURE OF A NOVEL INCLUSION COMPOUND——TETRAKIS

The title compound crystallizes in the space group C_5~4 with unit cell constants a=17.900 (5)A, b=18.466 (7)A, c=15.483 (4)A, β=92.78 (2)°and contains four formulaunits of MoFeS_(10)Cl_4N_4C_(34)H_(54). Intensities of 3499 independent reflections are collected withdiffractometer using MoKa radiation. The y coordinates of the Mo atoms are derived fromthe Patterson function. The parameters of the other atoms are found from successive Fourierand difference syntheses. The block-diagonal least-squares refinement for all atoms gives a final discrepancy factorR = 0.054. The result of structure analysis shows that this inclusion compound consists of threekinds of structural units and the oppositely charged complex ions [Mo(S_2CN(Et)_2)_4]~ and[FeCl_4]~- form a very interesting ionic host framework with infinite tunnels extending alongC direction and containing guest disulfide molecules PhCH_2SSCH_2Ph.     

STUDY ON THE SYNTHESIS OF POLYPERFLUOROTRIAZINE——The Synthesis and Polymerization of a Novel α,ω-Diiodoperfluorooxaalkyl s-Triazine Monomer*

In order to investigate synthetic route of polyperfluorotriazine elastomer, 2-trifluoromethyl4,6-bis(4′-iodo-2′-oxahexafluorobutyl)-1,3,5-triazine (1), a novel triazine monomer, was synthesized from 5-iodo-3-oxa-octafluoropentanesulfonyl fluoride (2) in eight-steps. 2 was reduced by potassium sulfite to the sulfinate (3), which was treated with hydriodic acid to yield 5-iodo-3oxa-hexafluoropentanoic acid (4). Compound 4 was transformed to 5-iodo-3-oxa-hexafluoropentanenitrile (7) through the corresponding ester 5 and amide 6. The desired product 1 was prepared by acylation-cyclodehydration of the imidoylamidine 9, obtained by condensation of the nitrile 7 with the amidine 8.The various methods for the esterification of perfluorocarboxylic acid were studied and a possible mechanism for the transformation of perfluorosulfinate to the corresponding perfluorocarboxylic acid by hydriodic acid was proposed.Crude 1 contained compounds 6, 11, 13, as impurities which were removed by low temperature crystallization followed by filtration through a short alumina column. The monomer 1 was polymerized by UV-irradiation in the presence of Hg with or without solvent. Polyperfluorooxaalkyl triazine 17 thus obtained showed good thermal stability. In the main chain of the polymer there was no weak unit of the uncyclized ring. Polymer 17 had an average molecular weight of ca. 1.33—2.0×10~4 (D. P.=27—42) and the temperature of 10% weight loss in nitrogen was 340℃.     

STUDY ON THE CONCENTRATION EFFECTS IN GPC IV A NEW METHOD FOR DETERMINATION OF SECOND VIRIAL COEFFICIENTS FROM THE CONCENTRATION EFFECTS

In this paper a new relation between the second virial coefficients A_2, (?)_w and (dV_(es)/dC)_c→0=K_s was derived from proposed model theory of concentration effects in GPC for mono-and poly-dispersed polymers. Based on this relation a new method for determination of second vifial coefficients from the combination of (dV_(es)/dC)_c→0=K_3, (?)_w and K_H measurements was proposed.The values of A_2 for mono-and poly-dispersed polystyrenes with molecular weight range from 10~4 to 10~6 in good and theta solvents were determined by proposed method. Results show that their values of A_2 are in agreement with those obtained by light scattering.     

THE CATALYTIC EFFECTS OF OXYGEN AND AMINES IN THE REDOX-INITIATED DIMERIZATION OF N-VINYLCARBAZOLE*

The redox reaction between N-vinylcarbazole (NVC) and various oxidants including Ce(Ⅳ), Fe(Ⅲ)and benzoylperoxide in methanol proceeds via the initial formation of the NVC N-cation radical which in turn leads to the formation of the NVC cyclic dimer, trans-1,2-dicarbazylcyclobutane. Molecular oxygen and a few arylamines are able to accelerate the rate of the formation and increase the yield of the dimer. The mechanism of this process and the functions of oxygen and arylamines are presented as follows: The participation of molecular oxygen is to facilitate the dissociation of the resulting reduced metal ion and the NVC N-cation radical ion pair or charge transfer complex, thereby releasing the free NVC N-cation radical and increase the rate of the formation and yield of the dimer. The arylamine in this reaction between NVC and oxidants can be viewed as electron transfer agent between NVC and the oxidant. Because the amines are present in small amount relative to the oxidants and can be regenerated in pr     

STUDIES ON THE STRUCTURE OF FORKED CONJUGATIVE SYSTEMS——THE CRYSTAL STRUCTURE AND CONFORMATION OF 2-BENZOYLTHIOPHENE

The crystal structure and the conformational properties of the title compound have been investigated by means of X-ray single diffraction and the PCILO methods. C_(11)H_8OS belongs to the orthorhombic system, the space group is P2_12_12_1, a=11.945(4), b 10.236(7), c=7.649(4), Z=4, D_c-1.37g/cm~3. The molecule is not planar structure because of steric hindrance. The thiophene ring and the phenyl ring make dihedral angles of 21°(θ_1) and 32°(θ_2) with the carbonyl frame plane, respectively. The lowestenergy conformation obtained by PCILO calculation is in agreement with the crystallinestatc conformation. In this paper, the molecular structure, the influence of steric hindrance and the groups' abilities to conjugate upon the conformation and the variations of the potential energy of the isolated molecule in the whole conformational space are discussed.     

STUDY ON THE MECHANISM OF 1-OCTENE ZIEGLER-NATTA POLYMERIZATION BASED ON THE NUMBER OF ACTIVE CENTERS

The number of active centers (C_p)-t and k_p-t profiles of Solvay type TiCl_3 - AlR_3 (R=C_2H_5, i-C_4H_9) or Stauffer AA TiCl_3-Al (C_2H_5)_3 catalyzed 1-octene polymerization were determined by using an acetyl chloride quenching method as well as kinetic data. The results show that in the studied systems k_p decreases when C_p increases, indicating the presence of two or more types of different active centers. The C_(p~(-t)) plots of the Solvay TiCl_3-AlR_3 systems show the presence of both stable active centers and unstable centers which decay in the polymerization process. The phenomena are explained based on a model of active center plurality. The increases of C_p in the induction periods are also discussed.