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991.
Nieves Carro Julio Cobas Nahid Brikat Isabel García María Ignacio Ana Mouteira 《Journal of Analytical Chemistry》2021,76(8):960-974
Journal of Analytical Chemistry - In this work, a method for the determination of nine polychlorinated biphenyls (PCBs) in three polymer types (polyethylene terephthalate, PET; unplasticized... 相似文献
992.
Mónica García-Mardones Isabel Bandrés M. Carmen López Ignacio Gascón Carlos Lafuente 《Journal of solution chemistry》2012,41(10):1836-1852
Thermophysical properties of two pyridinium-based ionic liquids, 1-ethyl-2-methylpyridinium bis(trifluoromethylsulfonyl)imide and 1-propyl-2-methylpyridinium bis(trifluoromethylsulfonyl)imide, have been measured from 278.15 to 323.15?K, with a temperature step of 2.5?K. The properties measured were: densities, speeds of sound, refractive indices, surface tensions, isobaric molar heat capacities, electrical conductivities and viscosities. Thermal properties were also recorded in the temperature range from 100 to 320?K. From the experimental results coefficients of thermal expansion, isentropic compressibilities, molar refraction and surface enthalpies and entropies have been determined. Moreover, a theoretical study has been performed using ab initio calculations, level of theory HF/6-31G(d). From this study, we have obtained qualitative information about the magnitude and the directionality of the cation?Canion interactions which allows a better understanding of the physico-chemical properties of these ionic liquids. 相似文献
993.
Katarzyna Rajkowska Anna Kozirg Anna Otlewska Magorzata Piotrowska Elena Atrin-Blasco Isabel Franco-Castillo Scott G. Mitchell 《Molecules (Basel, Switzerland)》2020,25(23)
Moulds inhabiting mineral-based materials may cause their biodeterioration, contributing to inestimable losses, especially in the case of cultural heritage objects and architectures. Fungi in mouldy buildings may also pose a threat to human health and constitute the main etiological factor in building related illnesses. In this context, research into novel compounds with antifungal activity is of high importance. The aim of this study was to evaluate the antifungal activity of polyoxometalate-ionic liquids (POM-ILs) and their use in the eradication of moulds from historical brick. In the disc diffusion assay, all the tested POM-ILs inhibited growth of a mixed culture of moulds including Engyodontium album, Cladosporium cladosporioides, Alternaria alternata and Aspergillus fumigatus. These were isolated from the surfaces of historical brick barracks at the Auschwitz II-Birkenau State Museum in Oświęcim, Poland. POM-IL coatings on historical brick samples, under model conditions, showed that two compounds demonstrated very high antifungal activity, completely limiting mould growth and development. The antifungal activity of the POM-ILs appeared to stem from their toxic effects on conidia, as evidenced by environmental scanning transmission electron microscopy observations. The results herein indicated that POM-ILs are promising disinfectant materials for use not only on historical objects, but probably also on other mineral-based materials. 相似文献
994.
Efficient routes for the gram-scale preparation of the proline analogues that bear a phenyl substituent attached to the pyrrolidine β carbon (cis- and trans-β-phenylproline) have been developed. The cis derivative was synthesized from N-Boc-β-alanine in six steps and 78% overall yield. The generation of a vinyl triflate with full regiochemical control together with a high-yielding cross-coupling reaction and a completely stereoselective hydrogenation are at the basis of the high efficiency of the procedure. Epimerization of the cis β-phenylproline derivative with lithium bis(trimethylsilyl)amide provided access to the trans isomer. 相似文献
995.
996.
Rodrigues Ana Luísa Dias Maria Isabel Rocha Fernando Prudêncio Maria Isabel Marques Rosa Russo Dulce Cardoso Guilherme 《Journal of Radioanalytical and Nuclear Chemistry》2019,321(2):541-556
Journal of Radioanalytical and Nuclear Chemistry - The genesis and development of calcretes are discussed by using nuclear and related methods of analyses. In the studied calcrete, smectite is the... 相似文献
997.
Dr. Isabel Fuentes Jordi Pujols Prof. Dr. Clara Viñas Prof. Dr. Salvador Ventura Prof. Dr. Francesc Teixidor 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(55):12820-12829
An inorganic sandwich molecule, Na[Co(C2B9H11)2], able to produce vesicles through self-assembly and known to produce strong dihydrogen-bond interactions with amine groups is capable of interacting with proteins. This dual non-bonding ability of Na[Co(C2B9H11)2] is what makes this molecule unique: it can be firmly anchored to a protein surface and is capable of extending over it. To prove this, the widely available bovine serum albumin (BSA), which has many pendant amino groups in its structure, has been taken as the model protein. It has been found that around 100 molecules of Na[Co(C2B9H11)2] preserve the native structure of BSA, while endorsing it with a significantly increased stability with respect to chemical- and thermal-induced denaturation due to efficient encapsulation. The advantages of this encapsulation technique are two-fold; the first is its simplicity as it relies on the anchoring capacity of Na[Co(C2B9H11)2] to the surface of the protein through the amine-containing residues and the second is its self-assembling capacity allowing it to spread across the surface. The dense shield of protection offered by Na[Co(C2B9H11)2] has been demonstrated by the inhibition of BSA pseudo-esterase activity, which indicates that the inorganic corset around BSA protects its reactive surface residues, thereby preventing their acetylation. 相似文献
998.
Nucleophilic Additions to Coordinated 1,10‐Phenanthroline: Intramolecular,Intermolecular, Reversible,and Irreversible 下载免费PDF全文
Rebeca Arévalo Dr. M. Isabel Menéndez Dr. Ramón López Dr. Isabel Merino Dr. Lucía Riera Dr. Julio Pérez 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(50):17972-17975
KN(SiMe3)2 reacts with [Re(CO)3(phen)(PMe3)]OTf via reversible addition to the phen ligand and irreversible deprotonation of the PMe3 ligand followed by intramolecular attack to phen by the deprotonated phosphane, whereas MeLi irreversibly adds to phen. The addition of MeLi has been shown to be intermolecular, unlike previously known nucleophilic additions to pyridines. 相似文献
999.
1000.
Dr. Khaleel I. Assaf Dr. Josef Holub Dr. Eduard Bernhardt Dr. Josep M. Oliva-Enrich Dr. M. Isabel Fernández Pérez Prof. Dr. Moisés Canle Dr. J. Arturo Santaballa Dr. Jindřich Fanfrlík Dr. Drahomír Hnyk Prof. Dr. Werner M. Nau 《Chemphyschem》2020,21(10):971-976
The supramolecular recognition of closo,closo-[B21H18]− by cyclodextrins (CDs) has been studied in aqueous solution by isothermal titration calorimetry and nuclear magnetic resonance spectroscopy. These solution studies follow up on previous mass-spectrometric measurements and computations, which indicated the formation and stability of CD ⋅ B21H18− complexes in the gas phase. The thermodynamic signature of solution-phase binding is exceptional, the association constant for the γ-CD complex with B21H18− reaches 1.8×106 M−1, which is on the same order of magnitude as the so far highest observed value for the complex between γ-CD and a metallacarborane. The nature of the intermolecular interaction is also examined by quantum-mechanical computational protocols. These suggest that the desolvation penalty, which is particularly low for the B21H18− anion, is the decisive factor for its high binding strength. The results further suggest that the elliptical macropolyhedral boron hydride is another example of a CD binder, whose extraordinary binding affinity is driven by the chaotropic effect, which describes the intrinsic affinity of large polarizable and weakly solvated chaotropic anions to hydrophobic cavities and surfaces in aqueous solution. 相似文献