Preparation and Crystal Structure of Sodium Hydrogen Epoxysuccinate

1 INTRODUCTION In recent years, sodium hydrogen epoxysuccinatehas gained special attention as a raw material of po-lyepoxysuccinic acid (PESA)[1～3]. We have synthes-ized sodium hydrogen epoxysuccinate by the reac-tion of H2O2 and maleic anhydride in water ca-talyzed by tungstate and obtained its single crystal[1].Its structure was determined by X-ray Nonius CAD4diffractometer. Up to now some crystal structures oforganic carboxyl sodium have been determined[4～6].In this paper we …     

Syntheses and Crystal Structures of Benzyl-and Cyclopentyl-Cyclopentadienyl Sodium Tetrahydrofuranate Complexes

The present paper covers syntheses and crystal structures of benzyl- and cy-clopentyl-cyclopentadienyl sodium tetrahydrofuranate complexes C6H5CH2C5H4Na·THF (1) and C5H9C5H4Na°THF (2). X-ray diffraction data of the title compounds were collected at a low temperature (about 210K). Structures of both the crystals belong to monoclinic space group P21/n with α=0. 9316(3) nm, b=1. 5161(4) nm, c= 0.9791(3) nm, β=91. 06(3)°Z=4 for (1) and α=1. 6120(7) nm, b=0. 9370(3) nm, c=1. 8475(7) nm, β=109.52(3)°Z = 8 for (2). Both structures were solved by using direct methods and refined by block-matrix least-squares to final values of R = 0. 044 for 520 observed reflections (1) and R = 0. 067 for 921 observed reflections (2). In the crystals the tetrahydrofuranate complexes C6H5CH2C5H4Na·THF and C5H9C5H4Na·THF adopt a puckered chain structure with η5-(C6H5CH2)C5H4 and η5-(C5H9)C5H4 rings connected by a bridge Na (THF) unit.     

Indriect Determination of CTMAB with Sodium Chloride and Ammonium Thiocyanate by Floatation and Separation of Zine

A new method for indirect determination of cetyl-trimethyl ammonium bromide (CTMAB) with NaCl and NH4SCH by floatation and separation of zinc has been studied.The study shows that Zn(Ⅱ） can associate with NH4SCN and CTMAB to form insoluble ternary ion-association complex,and the precipitate can float on the surface of the liquid phase.A good linear relationship is observed between the floatation yield(E%) of Zn(Ⅱ） and the amount of CTMAB.On the ground,CTMAB Can be indirectly determined by determining E% of Zn(Ⅱ）.The results were satisfactory.     

Indirect Determination of CTMAB with Sodium Chloride and Ammonium Thiocyanate by Floatation and Separation of Zinc

Cetyl-trimethylammoniumbromide(CTMAB)isaveryusefulcationicsurfactant,sothestudyondeterminationofCTMABassumesgreatimportance.AsmallamountofCTMABisgenerallydeterminedbyspectrophotometrybasingCTMABcombineswithtriazidetoformcoloredbinaryion-associationcomplex1-3.However,thosemethodsofdeterminationofCTMABhavedisadvantagesofsmalllinearrange,needofspecialreagent,determinationinbaseenvironment,etc.Inthispaper,indirectdeterminationofCTMABwithNaClandNH4SCNbyfloatationandseparationofZn(II…     

Complexation of 6-Deoxy-6-(aminoethyl)amino-β-cyclodextrin with Sodium Cholate and Sodium Deoxycholate

In order to study its guest binding and the inclusion phenomena, 6-deoxy-6-(aminoethyl)amino--cyclodextrin (CDN) was synthesised and its binding properties examined. The complexation phenomena of sodium cholate (NaC) and sodium deoxycholate (NaDC) with CDN has been monitored by the NMR method using ¹³C chemical shift data. The method of continuous variation Job's method has been used to determine the stoichiometry of these supramolecular complexes. The Job's plot confirms the 1 : 1 supramolecular complex for NaC: CDN and the 1 : 2 supramolecular complex for NaDC: CDN. The interaction of NaC and NaDC with CDN has been obtained through two-dimensional Rotational Nuclear Overhauser Effect Spectroscopy (ROESY) NMR. Equilibrium constants were also obtained from ¹³C chemical shift data (C-1, C-3 & C-4) at different pH values (7, 9, & 11).     

Effect of Sodium Alginate Concentration on Membrane Strength and Permeating Property of Poly-l-arginine Group Microcapsule

A novel poly-l-arginine microcapsule was prepared due to its nutritional function and pharmacological efficacy. A high-voltage electrostatic droplet generator was used to make uniform microcapsules. The results show that the membrane strength and permeating property are both remarkably affected with the changes of sodium alginate concentration. With the sodium alginate concentration increasing, gel beads sizes increase from 233μtm to 350μtm, release ratio is also higher at the same time, but the membrane strength decreases.     

Voltammetric Behavior of Sodium 7-Methoxyl-4''''-hydroxylisoflavone-3''''-sulfonate and Its Application

Introduction Daidzein (7,4'-bihydroxylisoflavone) is a main activ-ity constituent of the soybean isoflavones. It has activi-ties of hyperkinesias,14 inhibiting cancer cell growth,5,6 accelerating the formation of bone cells and playing a role of female hormone.7,8 Daidzein has been a medi-cine and used to treat coronary heart disease, hyperten-sion, cerebral block, cerebral hemorrhage sequela and cerebral thrombosis.9 However, because the solubility of daidzein is poor, its biological utilizat…     

Trifluoromethylation of Carbonyl Compounds with Sodium Trifluoroacetate

In the presence of copper （I） halide as catalyst, a variety of carbonyl compounds could be trifluoromethylated with sodium trifluoroacetate to give the corresponding alcohols in moderate to high yields.     

Scale Inhibition of Green Inhibitor Polyepoxysuccinic Sodium

Polyepoxysuccinic acid (PESA) is the green water treatment agents recognized all over the world[1-3]. It is found that when PESA is used alone, it had good scale inhibition. PESA should be included in the category of green scale inhibitor. PESA is synthesized with maleicanhydride in the presence of catalysts. The effect on scale-in-hibiting property of the product from amount and feed times of catalyst, the reaction temperature, the reaction time were investigated. The optimum reaction c…     

Sodium Bismuthate–Induced Oxidation of Baccatin

Sodium bismuthate in acetic acid has proven very effective in the oxidation of allyic alcohols. An extension of this oxidation method using baccatin as the substrate has provided keto‐baccatin, an important compound for the semisynthesis of Taxol and Taxotere.     

Synthesis and Crystal Structure of Complex of Sodium Perrhenate with Tetraethyl p-tert-Butylcalix[4]arene Tetraacetate

Recently,theconformationofthecalixarenehasbeenshowntobeimportantincontrollingtheseIectivityofthereceptor.Forexample,sodiumioncouldbeboundverystronglybyesterderivativesofcalix[4]areneintheconeconformationl.Wehavefoundthatinthepresenceofcertainamountofsodiumion,microamountofReO4-canbequantitativelyextractedintol,2-dichloroethanebytheligandtetraethylp-tert-butylcalix[4]arenetetraacetate(L).ItshowsthatthepresenceofNa inaqueoussolutioncanpromotetheformationofhydrophobiccomplex[NaL] .ReO'-whichc…     

Polymerization/Depolymerization Mechanism for “Living” Sodium Poly-α-Methylstyryl and Sodium Polystyryl

The equilibrium polymerization of sodium poly--methylstyryl in tetrahydrofuran was studied in the temperature range from -60 to 15°C. For the first time, the reversible process of formation/cleavage of the chemical bond was theoretically analyzed in terms of the electronic excitation views. On this basis a new mechanism of the living polymer depolymerization was proposed. The geometry, electronic structure of the model fragments of living polymers comprised of two units were calculated ab initioby the 6-31G* method. The energies of the triplet excited states belonging to the complex of the reactants, on the one hand, and to the reaction product, on the other, proved to be close. The theoretical activation energies for depolymerization of sodium poly--methylstyryl reasonably agree with the experiment.     

Facile and Chemoselective Reduction of Carboxylic Acids into Alcohols via Sodium Borohydride Reduction of N‐Acylbenzotriazoles

Carboxylic acids are converted into corresponding alcohols by chemoselective reduction of their benzotriazole amides with sodium borohydride.     

Synthesis and Characterization of Novel Layered Lithium Sodium Silicate （Silinaite） and the Mesoporous Materials from Silinaite

Novel layered silinaite has been synthesized using an aqueous mixture of water glass, LiOH and NaOH under hydrothermal crystallization. Subsequently transformation of silinaite into mesoporous materials (SDM) was achieved at mild condition using cetyltrimethylammonium bromide as structure-directing agents. The resulting samples were characterized by XRD, SEM, FTIR nitrogen adsorption-desorption isotherms and catalytic performance in bulky molecular involved reaction. The results revealed that synthesized mesoporous materials derived from the silinaite exhibited an ordered hexagonal crystal structure with average pore diameter 2.7 nm and BET surface area 817m2/g. The SDM-supported ZnCl2 catalyst, prepared by impregnation-evaporation method, retained the mesoporous structure and showed high selectivity in alkylation of benzene with benzyl chloride.     

Conductance of Lithium and Sodium Perchlorates and Tetraphenylborates in 2-Butanone from −35 to 25°C

Conductances of dilute solutions of LiClO₄, NaClO₄, LiBPh₄ and NaBPh₄ in 2-butanone were measured at seven temperatures from ?35 to 25°C. The limiting molar conductivities and association constants were evaluated using the conductance equation of Fuoss and Justice (including the Chen effect). The distance parameter was fixed at the Bjerrum distance. The limiting ionic conductivities, determined by assuming equal ionic conductivities of the i-Am₃ BuN⁺ and BPh ₄ ^? ions at all temperatures, were related to the crystallographic ionic radii using the Hubbard–Onsager model of dielectric friction corrected for the inhomogeneity of the electric field. The activation enthalpy of ionic transport in 2-butanone is almost independent of the nature of the electrolyte. The Walden products do not vary with the temperature. The correction to the conductance parameters for dielectric saturation computed for M⁺ClO ₄ ^? associates was found to be small. Thermodynamic functions characterizing the association process were evaluated from K _A data and their dependences on the temperature. The short-range, noncoulombic contributions to the Gibbs energy were estimated using Bjerrum's theory.     

Sn-Mediated Catalytic Asymmetric Reduction of Carbonyl Groups by Sodium Borohydride(or Sodium Borodeuteride)

Two remarkable reducing agents NaBH_4 (or NaBD_4)/SnCl_2(orSnCl_4·2Et_2O) with chiral ligands are applied to the asymmetricreduction of carbonyl compounds with excellent chemical yieldsand enantioselective excesses.     

Palladium-Catalyzed Desulfitative Cross-Coupling of Sodium Arylsulfinates with Aryl Bromides and Chlorides： An Alternative Convenient Synthesis of Biaryls

An alternative method for synthesis of biaryls has been developed through the Pd catalyzed desulfitative coupling reaction of sodium arylsulfinates with aryl bromides and chlorides. The procedure tolerates a variety of functional groups, such as cyano, formyl, acetyl, chloro, methoxy, trifluoromethyl and heteroaromatic unit. The desired products were obtained in moderate to excellent yields under relatively mild reaction conditions without additives, base or co-catalyst.     

Determination of Iron in Layered Crystal Sodium Disilicate and Sodium Silicate by Flame Atomic Absorption Spectrometry with Boric Acid as a Matrix Modifier

As a novel type builder for phosphate-free detergent1,2, layered crystal sodium disilicate has many advantages over other builders for phosphate detergents. The raw material of layered crystal sodium disilicate is sodium silicate. Because of the effects o…     

Photo-induced Synthesis and Characterization of Poly（methyl methacrylate） Grafted Sodium Salt of Partially Carboxymethylated Guar Gum

Photo-induced graft copolymerization of methyl methacrylate（MMA） onto sodium salt of partially carboxymethylated guar gum（Na-PCMGG, DS = 0.291） was carried out in an aqueous medium using ceric ammonium nitrate（CAN） as photoinitiator to synthesize a novel graft copolymer, Na-PCMGG-g-PMMA, which may find its potential application as a metal adsorbent. The influences of synthesis variables such as concentrations of photoinitiator（CAN）, nitric acid and monomer（MMA） as well as reaction time, temperature and amount of substrate on the grafting yields were studied and the reaction conditions for optimum photo-grafting were evaluated. At optimum concentration, the maximum values of the grafting yields achieved were G = 271.61% and GE = 63.89%. The experimental results were found to be in very good agreement with the proposed kinetic scheme. The photo-graft copolymerization of MMA onto Na-PCMGG（ DS = 0.291） was also carried out in the presence and absence of ultraviolet radiation for studying the efficiency of the photoinitiator. The influence of carboxymethyl groups introduced onto the guar gum molecules with regard to its behavior towards ultra-violet radiation induced grafting with MMA was also investigated. Photo-grafting process was confirmed and the products were characterized with the help of the spectroscopic（1H-NMR and FTIR） and SEM techniques.