Crystal and Molecular Structure of Di－chloro－bis（р－methylphenylbutylsulfide） Palladium（Ⅱ）

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ent‐Kaurane Diterpenoids from Isodon japonicus

Two new 6,7‐seco‐ent‐kaurane diterpenoids, isojaponins A ( 1 ) and B ( 2 ), together with 18 known ent‐kaurane diterpenoids were isolated from the aerial parts of Isodon japonicus. The structures of the two new compounds were elucidated by extensive 1D‐ and 2D‐NMR spectroscopic methods in combination with MS experiments.     

New evidences of glass transitions and microstructures of soy protein plasticized with glycerol

Soy protein isolate (SPI) and glycerol were mixed under mild (L series) and severe (H series) mixing conditions, respectively, and then were compression-molded at 140 degrees C and 20 MPa to prepare the sheets (SL and SH series). The glass transition behaviors and microstructures of the soy protein plasticized with glycerol were investigated carefully by using differential scanning calorimetry and small-angle X-ray scattering. The results revealed that there were two glass transitions in the SPI/glycerol systems. When the glycerol contents ranged from 25 to 40 wt.-%, all of the SL- and SH-series sheets showed two glass transition temperatures (T(g1) and T(g2)) corresponding to glycerol-rich and protein-rich domains, respectively. The T(g1) values of the sheets decreased from -28.5 to -65.2 degrees C with an increase of glycerol content from 25 to 50 wt.-%, whereas the T(g2) values were almost invariable at about 44 degrees C. The results from wide-angle X-ray diffraction and small-angle X-ray scattering indicated that both protein-rich and glycerol-rich domains existed as amorphous morphologies, and the radii of gyration (R(g)) of the protein-rich domains were around 60 nm, a result suggesting the existence of stable protein domains. The results above suggest that protein-rich domains were composed of the compact chains of protein with relatively low compatibility to glycerol and glycerol-rich domains consisted of relative loose chains that possessed good compatibility with glycerol. The significant microphase separation occurred in the SPI sheets containing more than 25 wt.-% glycerol, with a rapid decrease of the tensile strength and Young's modulus. [illustration in text].     

In situ XPS studies of perovskite oxide surfaces under electrochemical polarization

An in situ XPS study of oxidation-reduction processes on three perovskite oxide electrode surfaces was carried out by incorporating the materials in an electrochemical cell mounted on a heated sample stage in an ultrahigh vacuum (UHV) chamber. Electrodes made of powdered LaCr(1-x)Ni(x)O(3-delta) (x = 0.4, 1) showed changes in the XPS features of all elements upon redox cycling between formal Ni3+ and Ni2+ oxidation stoichiometries, indicating the delocalized nature of the electronic states involved and strong mixing of O 2p to Ni 3d levels to form band states. The surface also showed changes in adsorption capacity for CO2 upon reduction as a result of increased nucleophilicity of surface oxygen. Another perovskite oxide, La(0.5)Sr(0.5)CoO(3-delta), laser deposited as highly oriented thin films on (100) oriented yttria-stabilized zirconia (YSZ), also showed evidence of both local and nonlocal effects in the XPS features upon redox cycling. In contrast to LaCr(1-x)Ni(x)O(3-delta), redox cycling mainly affected the XPS features of cobalt with little effect on oxygen. This signifies reduced participation of O 2p states in the conduction band of this material. Small changes in surface cation stoichiometry in this film were observed and attributed to mobility of the A-site Sr dopant under polarization.     

2‐Amino‐7‐chloro‐2′‐deoxy­tubercidin

In 4‐chloro‐7‐(2‐de­oxy‐β‐d ‐erythro‐pento­furanos­yl)‐7H‐pyr­rolo­[2,3‐d]­pyrimidine‐2,4‐diamine, C₁₁H₁₄ClN₅O₃, the conformation of the N‐glycosylic bond is between anti and high‐anti [χ = −102.5 (6)°]. The 2′‐deoxy­ribofuranosyl unit adopts the C3′‐endo‐C4′‐exo (³T₄) sugar pucker (N‐type) with P = 19.6° and τ_m = 32.9° [terminology: Saenger (1989). Landolt‐Börnstein New Series, Vol. 1, Nucleic Acids, Subvol. a, edited by O. Madelung, pp. 1–21. Berlin: Springer‐Verlag]. The orientation of the exocyclic C4′—C5′ bond is +ap (trans) with a torsion angle γ = 171.5 (4)°. The compound forms a three‐dimensional network that is stabilized by four inter­molecular hydrogen bonds (N—H⋯O and O—H⋯N) and one intra­molecular hydrogen bond (N—H⋯Cl).     

L-canavanine is a time-controlled mechanism-based inhibitor of Pseudomonas aeruginosa arginine deiminase

The mechanism for inhibition of the Pseudomonas aeruginosa arginine deiminase (PaADI) by the arginine analogue l-canavanine was investigated. Inhibition by this substance (kinact = 0.31 +/- 0.03 min-1 and Ki = 1.7 +/- 0.5 mM) is associated with the formation of a modestly stable S-alkylthiouronium intermediate, detected by using kinetic techniques and identified by using electrospray ionization mass spectrometry. The electronic and/or orientation effects, caused by oxygen-for-methylene substitution in l-canavanine, on the rate of enzyme regeneration from the S-alkylthiouronium intermediate could serve as the basis for a strategy for the rational design of new slow substrate inhibitors of ADI.     

SEPARATING SCN^- FROM DESULPHURIZATION WASTE SOLUTION OF COCKING PLANT BY D241 RESIN

SCN- from desulphurization waste solution of cocking plant was separated by D241 anion exchange resin. When SCN- concentration of the waste liquid is 0.116mg/ml, its dynamic exchange capability is 93.61 mg/g resin. The condition of use KOH as eluted solution to elute SCN- is KOH concentration 0.5mol/L, flow velocity 60 ml/h, with 60ml eluted solution can completely elute SCN- which exchanged from waste solution. Vaporized the eluted solution, obtain the KSCN crystal in which the concentration of SCN- is 53.34%, converts to KSCN is 89.2%. SCN- crystal was separate out from Na2S2O3/KOH mixed solution. The relationship between the proportion of Na2S2O3/KOH,free liquids in crystal and the saturation solution volume when crystal appear、 the content of KSCN in crystal: the ratio of K2S2O3/KSCN show direct ratio with the saturation solution volume when the crystal birth, r2=0.9964; when the ratio of K2S2O3/KSCN is between 0.15 and 0.25, the content of SCN in the crystals grow with K2S2O3 content increases, the content of free liquids in crystal also along with it increase; When the ratio of Na2S2O3/KOH is 0.15, the content of SCN- is 54.56%;convert to KSCN is 76.2%. When the ratio of K2S2O3/KSCN is 0.25, the content of SCN- is 65.28%;convert to KSCN is 91.2%. When the ratio of K2S2O3/KSCN exceeds 0.25, the content of SCN- in the crystals and the content of free liquids in crystal reduce when the ratio of K2S2O3/KSCN increase.     

Elektrophorese der halogenokomplexe von Hg(II), Bi(III), Cd(II), Pb(II) und -Cu(II) : Chlorokomplexe in chlorwasserstoffsäure

An apparatus for heavy-current and high-tension electrophoresis on filter paper is described This apparatus enables one to avoid the difficulties that occur in electrophoresis in base electrolytes that are highly concentrated or show greater electric conductivity The zones migrate along the paper strips with constant speed and, consequently, it is possible to measure the mobility The effective length of the filter paper strips is 660 mm Correction of the apparent mobility in the porous adsorbent is treated thoroughly.Diagrams of the electrophoretic mobility of the chloro-complexes of Hg(II), Bi(III), Cd(II), Pb(II), and Cu(II) in hydrochloric acid, are given in the experimental part The concentration of the hydrochloric acid varied between 0.1N and 6N In 6N HCl all the metals investigated are present asani onic complexes. Hg, Bi.Cd, and Pb chloro-complexes show a pronounced maximum of mobility in the anionic range. The sequence of the zones in the direction anode to cathode is Hg, B1, Cd, Pb, Lu al 0.1–2.3N HCl and B1, Hg, Cd, Pb.Cu at2.3–6N HCl.Finally, the electrophoretic separation of a mixture of Hg, Bi, Cd, Pb, Cu in 1N, 2N and 4N HCl is illustrated Complete separation of the zones was achieved in each experiment     

Chiral N,N′-dioxide/Mg(OTf)2 complex-catalyzed asymmetric [2,3]-rearrangement of in situ generated ammonium salts

Catalytic enantioselective [2,3]-rearrangements of in situ generated ammonium ylides from glycine pyrazoleamides and allyl bromides were achieved by employing a chiral N,N′-dioxide/Mg^II complex as the catalyst. This protocol provided a facile and efficient synthesis route to a series of anti-α-amino acid derivatives in good yields with high stereoselectivities. Moreover, a possible catalytic cycle was proposed to illustrate the reaction process and the origin of stereoselectivity.

The Lewis acid catalyzed asymmetric [2,3]-rearrangement of quaternary ammonium ylides formed in situ from glycine pyrazoleamides and allyl bromides.