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41.
Jeffrey S. Boyer 《The Journal of chemical thermodynamics》2003,35(12):1917-1928
The standard molar heat capacity C°p,m of adenine(cr) has been measured using adiabatic calorimetry over the range 6<(T/K)<310 and the results used to derive thermodynamic functions for adenine(cr) at smoothed temperatures. At T=298.15 K, C°p,m=(142.67±0.29) J · K−1 · mol−1 and the third law entropy S°m=(145.62±0.29) J · K−1 · mol−1. The standard molar Gibbs free energy of formation ΔfG°m at T=298.15 K for crystalline adenine was calculated, using the standard molar enthalpy of formation for the compound and entropies of the elements from the literature, and found to be ΔfG°m=(301.4±1.0) kJ · mol−1. The results were combined with solution calorimetry and solubility measurements from the literature to yield revised values for the standard molar thermodynamic properties of aqueous adenine at T=298.15 K: ΔfG°m=(313.4±1.0) kJ · mol−1, ΔfH°m=(129.5±1.4) kJ · mol−1, and Sm°=(217.68±0.44) J · K−1 · mol−1. 相似文献
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Mattia Mazza Cyrille Alliot Corinne Sinquin Sylvia Colliec-Jouault Pascal E. Reiller Sandrine Huclier-Markai 《Molecules (Basel, Switzerland)》2021,26(4)
(1) Background: Exopolysaccharide (EPS) derivatives, produced by Alteromonas infernus bacterium, showed anti-metastatic properties. They may represent a new class of ligands to be combined with theranostic radionuclides, such as 47Sc/44Sc. The goal of this work was to investigate the feasibility of such coupling. (2) Methods: EPSs, as well as heparin used as a drug reference, were characterized in terms of molar mass and dispersity using Asymmetrical Flow Field-Flow Fractionation coupled to Multi-Angle Light Scattering (AF4-MALS). The intrinsic viscosity of EPSs at different ionic strengths were measured in order to establish the conformation. To determine the stability constants of Sc with EPS and heparin, a Free-ion selective radiotracer extraction (FISRE) method has been used. (3) Results: AF4-MALS showed that radical depolymerization produces monodisperse EPSs, suitable for therapeutic use. EPS conformation exhibited a lower hydrodynamic volume for the highest ionic strengths. The resulting random-coiled conformation could affect the complexation with metal for high concentration. The LogK of Sc-EPS complexes have been determined and showing that they are comparable to the Sc-Hep. (4) Conclusions: EPSs are very promising to be coupled with the theranostic pair of scandium for Nuclear Medicine. 相似文献
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Raymond F. Boyer 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(7):1411-1434
A formal history of styrene and polystyrene from 1839 through 1952 appears in the Styrene monograph edited by Boundy and writer but now out of print. Updating of the story by several teams of Dow writers appeared in the Kirk-Othmer Encyclopedia, the Encyclopedia of Polymer Science and Technology, and the SPE Award address of Amos. We propose a more personalized history written from the perspective of one whose 40-year professional career was involved in scientific and technological aspects of the subject. We view this history as a complex interplay of science, technology, industrial activity, management decisions, legal and patent activities, people, and the vagaries of World War II. Germany had an early industrial lead prior to 1941 with a monomer process and mass polymerization techniques. Original work on styrene-butadiene elastomers was another first. Germany also had a scientific lead as academic scientists such as Staudinger, Kern, Schulz, Jenckel, and Ueberreiter became involved in the chemistry and physics of styrene and polystyrene (PS). Mark was first in industry and then in the university. Several United States companies were active with styrene and PS, also prior to 1941. Involvement of the United States in World War II lead to a government decision to produce SBR. This catapulted styrene into a major synthetic chemical. The lead passed from Germany to the United States, especially with the large excess capacity for monomer after 1945. Management decisions encouraged diverse large-scale polymer uses for styrene, aided by the low price for the monomer. Through a bizarre series of events (war, people, and legal action), proprietary industrial knowledge in both Germany and the United States had diffused into the domain of public knowledge. Styrene and PS now face the problems of any petrochemical product. 相似文献
47.
A Beckmann Rearrangement/Friedel-Crafts strategy was utilized to prepare 5-amidotetralones in high yield. 相似文献
48.
Aïcha Mbarek Geneviève Chadeyron Daniel Avignant Damien Boyer Mohieddine Fourati Daniel Zambon 《Journal of Sol-Gel Science and Technology》2013,68(2):193-203
The sol–gel chemistry route has successfully been used to prepare samples of LnP5O14 (Ln = La, Gd) pentaphosphates from lanthanides chlorides and phosphorous pentoxide dissolved in isopropanol. Crystallized powders of single phase were obtained after calcination of gels at 350 °C. The structural characterizations of materials were investigated by means of X-ray diffraction as well as infrared and Raman spectroscopies, whereas their thermal behavior has been studied by differential thermal analyse and thermogravimetric analyses. Powders morphology was analyzed by means of scanning electron microscopy and laser granulometry. The photoluminescence properties of the Eu3+ ions in sol–gel derived LaP5O14 and GdP5O14 samples were investigated and compared with homologous samples synthesized by the conventional solid state reaction. 相似文献
49.
Walid Mabrouk Ridha Lafi Jean Franois Fauvarque Amor Hafiane Cyrille Sollogoub 《先进技术聚合物》2021,32(1):304-314
The purpose of this work is to study the desalination of brackish water using a new ion exchange membrane, made from sulfochlorated polyethersulfone (Cl‐PES), and crosslinked using aminated polyethersulfone (NH2‐PES) as a crosslinking reagent. This membrane, named ClNH2 membrane, has been obtained by reaction between Cl‐PES with 1.3 SO2Cl groups per monomer unit and 0.2 equivalent amount of NH2‐PES. ClNH2 membrane has been characterized in terms of contact angle, transport number, intrinsic conductivity, and water uptake (as a function of temperature). Electrodialysis performances of the newly synthetized membranes have been measured using an electrodialysis cell at a laboratory scale and compared to commercial membranes. All the experiments have been performed using synthetic brackish water solutions prepared from sodium chloride salts with different concentrations (varying from 0.5 to 5.0 g/L). The concentration of different water samples obtained has been found to be below the amount recommended by the World Health Organization (WHO) for drinking water. 相似文献
50.
Tailoring the Structure of Two‐Dimensional Self‐Assembled Nanoarchitectures Based on NiII–Salen Building Blocks 下载免费PDF全文
Dr. Marta Viciano‐Chumillas Dongzhe Li Dr. Alexander Smogunov Dr. Sylvain Latil Dr. Yannick J. Dappe Dr. Cyrille Barreteau Prof. Talal Mallah Dr. Fabien Silly 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(42):13566-13575
The synthesis of a series of NiII–salen‐based complexes with the general formula of [Ni(H2L)] (H4L=R2‐N,N′‐bis[R1‐5‐(4′‐benzoic acid)salicylidene]; H4L1: R2=2,3‐diamino‐2,3‐dimethylbutane and R1=H; H4L2: R2=1,2‐diaminoethane and R1=tert‐butyl and H4L3: R2=1,2‐diaminobenzene and R1=tert‐butyl) is presented. Their electronic structure and self‐assembly was studied. The organic ligands of the salen complexes are functionalized with peripheral carboxylic groups for driving molecular self‐assembly through hydrogen bonding. In addition, other substituents, that is, tert‐butyl and diamine bridges (2,3‐diamino‐2,3‐dimethylbutane, 1,2‐diaminobenzene or 1,2‐diaminoethane), were used to tune the two‐dimensional (2D) packing of these building blocks. Density functional theory (DFT) calculations reveal that the spatial distribution of the LUMOs is affected by these substituents, in contrast with the HOMOs, which remain unchanged. Scanning tunneling microscopy (STM) shows that the three complexes self‐assemble into three different 2D nanoarchitectures at the solid–liquid interface on graphite. Two structures are porous and one is close‐packed. These structures are stabilized by hydrogen bonds in one dimension, while the 2D interaction is governed by van der Waals forces and is tuned by the nature of the substituents, as confirmed by theoretical calculations. As expected, the total dipolar moment is minimized 相似文献