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Amit S. Nagare Arpan Manna Pramod D. Sonawane Anil Kumar 《Journal of Physical Organic Chemistry》2015,28(11):665-673
Prevailing classification of salts based on their effect in solubility and stability of proteins in aqueous solution predicts that tetraalkylammonium salts, guanidinium chloride (GnCl), LiClO4 act as salting‐in (S/I) and LiCl, NaCl act as salting‐out (S/O) in aqueous conditions. In the same context the behaviour of GnCl, LiClO4 and LiCl are contradictory in polar solvents like ethylene glycol and formamide. In these solvents, expected salt effect shows just opposite nature from their usual expectation. However, in the aqueous solution salts like tetraalkylammonium halide (R4NX, R = alkyl group, X = Br group) behave like salting‐in salts. The physicochemical origin of the salting in effect of R4NX type of salts has been discussed elaborately in the present work. The role of cations in terms of substitution of various alkyl groups on R4NX has been systematically presented here on the basis of experimental kinetic and thermodynamic studies. The abnormal behaviour of R4NX salts in aqueous solution has also been explained by the Setschenov equation (ks) and Δμsolvation values, which highlights their individual nature out of common properties of R4NX. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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Three lanthanide‐based two‐dimensional (2D) coordination polymers (CPs), [Ln(L)(H2O)2]n, {H3L=(HO)2P(O)CH2CO2H; Ln=Dy3+ (CP 1 ), Er3+ (CP 2 )} and [{Gd2(L)2(H2O)3}.H2O]n, (CP 3 ) were hydrothermally synthesized using phosphonoacetic acid as a linker. Structural features revealed that the dinuclear Ln3+ nodes were present in the 2D sheet of CP 1 and CP 2 while in the case of CP 3 , nodes were further connected to each other forming a chain‐type arrangement throughout the network. The magnetic studies show field‐induced slow magnetic relaxation property in CP 1 and CP 2 with Ueff values of 72 K (relaxation time, τ0=3.05×10?7 s) and 38.42 K (relaxation time, τ0=4.60×10?8 s) respectively. Ab‐initio calculations suggest that the g tensor of Kramers doublet of the lanthanide ion (Dy3+ and Er3+) is strongly axial in nature which reflects in the slow magnetic relaxation behavior of both CPs. CP 3 exhibits a significant magnetocaloric effect with ?ΔSm=49.29 J kg?1 K?1, one of the highest value among the reported 2D CPs. Moreover, impedance analysis of all the CPs show high proton conductivity with values of 1.13×10?6 S cm?1, 2.73×10?3 S cm?1 and 2, 6.27×10?6 S cm?1 for CPs 1 – 3 , respectively, at high temperature (>75 °C) and maximum 95 % relative humidity (RH). 相似文献
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A wide variety of [1,2,3]triazolo[5,1-c][1,4]benzoxazines were synthesized through palladium-copper catalyzed reactions of 1-azido-2-(prop-2-ynyloxy)benzene with aryl/vinyl iodides. A plausible reaction mechanism has also been proposed. 相似文献
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Invoking Pairwise Interactions in Water‐Promoted Diels–Alder Reactions by using Ionic Liquids as Cosolvents 下载免费PDF全文
Rate constants and derived activation parameters of organic reactions in aqueous media, in particular Diels–Alder reactions, are sensitive to the presence of cosolvents in water. To enhance the solubility window of water, we introduced ionic liquids as cosolvents in the aqueous Diels–Alder reaction between anthracene‐9‐carbinol and N‐ethylmaleimide. The reactive potentials of the organic compounds are parameterized by using semi‐empirical quantum chemical methods. The principle of Savage–Wood additivity of group interactions is used to quantify the pairwise group interactions among chemically inert ionic liquids and organic reactants, both at initial and transition states of the reaction. The present approach shows promise, as the use of simple calculations from easily available kinetic data can help researchers to understand the versatility of green ionic‐liquid alternatives to volatile organic solvents. 相似文献
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Metal‐Catalyzed C−H Bond Activation of 5‐Membered Carbocyclic Rings: A Powerful Access to Azulene,Acenaphthylene and Fulvene Derivatives 下载免费PDF全文
Azulene, acenaphthylene and fulvene derivatives exhibit important physical properties useful in materials chemistry as well as valuable biological properties. Since about two decades ago, the metal‐catalyzed functionalization of such compounds, via C?H bond activation of their 5‐membered carbocyclic ring, proved to be a very convenient method for the synthesis of a wide variety of azulene, acenaphthylene and fulvene derivatives. For such reactions, there is no need to prefunctionalize the 5‐membered carbocyclic rings. In this review, the progress in the synthesis of azulene, acenaphthylene and fulvene derivatives via metal‐catalyzed C?H bond activation of their 5‐membered carbocyclic ring are summarized. 相似文献
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In this paper we introduce a controlled teleportation protocol for transferring arbitrary two-qubit states bilaterally between Alice and Bob. The bidirectional teleportation protocol is supervised by a controller Charlie. A ten-qubit entangled quantum channel shared between Alice, Bob and Charlie is utilized. The protocol depends on Bell state measurements by Alice and Bob and single-qubit measurements by Charlie. 相似文献