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排序方式: 共有1397条查询结果,搜索用时 15 毫秒
1.
Journal of Fluorescence - We synthesized an original reversible colorimetric chemosensor PDJ... 相似文献
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Peralta Cecilia Mariana Acosta Gimena Henestrosa Cecilia Gil Raúl Andrés Fernández Liliana Patricia 《Journal of Analytical Chemistry》2022,77(3):308-317
Journal of Analytical Chemistry - The present development involved a flow injection strategy using a mini-column of multiwalled carbon nanotubes and fluorescent detection (λex of 283 nm,... 相似文献
3.
Dr. Felipe L. Coelho Eduarda S. Gil Dr. Paulo F. B. Gonçalves Dr. Leandra F. Campo Dr. Paulo H. Schneider 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(34):8157-8162
In this work, a series of 2-chalcogenylindoles was synthesized by an efficient methodology, starting from chalcogenoalkynes, including a previously unreported tellurium indole derivative. For the first time, these 2-substituted chalcogenylindoles were obtained in the absence of metal catalyst or base, under thermal conditions only. In addition, the results described herein represent a methodology with inverse regioselectivity for the chalcogen functionalization of indoles. 相似文献
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Dr. Pere Miró Dr. Bess Vlaisavljevich Dr. Adria Gil Dr. Peter C. Burns Dr. May Nyman Dr. Carles Bo 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(25):8571-8578
A wide range of uranyl–peroxide nanocapsules have been synthesized using very simple reactants in basic media; however, little is known about the process to form these species. We have performed a density functional theory study of the speciation of the uranyl ions under different experimental conditions and explored the formation of dimeric species via a ligand exchange mechanism. We shed some light onto the importance of the excess of peroxide and alkali counterions as a thermodynamic driving force towards the formation of larger uranyl–peroxide species. 相似文献
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Dr. Yolimar Gil Dr. Alejandro Castro-Alvarez Dr. Pablo Fuentealba Prof. Evgenia Spodine Dr. Daniel Aravena 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(48):e202200336
Enhancement of axial magnetic anisotropy is the central objective to push forward the performance of Single-Molecule Magnet (SMM) complexes. In the case of mononuclear lanthanide complexes, the chemical environment around the paramagnetic ion must be tuned to place strongly interacting ligands along either the axial positions or the equatorial plane, depending on the oblate or prolate preference of the selected lanthanide. One classical strategy to achieve a precise chemical environment for a metal centre is using highly structured, chelating ligands. A natural approach for axial-equatorial control is the employment of macrocycles acting in a belt conformation, providing the equatorial coordination environment, and leaving room for axial ligands. In this review, we present a survey of SMMs based on the macrocycle belt motif. Literature systems are divided in three families (crown ether, Schiff-base and metallacrown) and their general properties in terms of structural stability and SMM performance are briefly discussed. 相似文献
9.
Gil A. Ferreira Dr. Cláudio M. Nunes Prof. Dr. A. J. Lopes Jesus Prof. Dr. Rui Fausto 《European journal of organic chemistry》2023,26(27):e202300310
The geometric and electronic structure of 1,3-dipolar species, in particular of nitrile imines, can be surprisingly intricate. A particular example is the C-phenyl-nitrilimine, which exists as two energy minima that constitute bond-shift isomers. To examine the effect of substituents in the phenyl ring, here we investigate the meta and para OH substituted derivatives. These two nitrile imines were generated in an argon matrix by UV-irradiation of 2H-tetrazole precursors and found to photoisomerize to carbodiimides via 1H-diazirines. The different effects of the OH substitution in meta and para positions on the bond-shift isomerism are rationalized with the support of Natural Resonance Theory and Hirshfeld atomic charges. The understanding of how substitution affects the structural characteristics of C-phenyl-nitrilimines, opens a door to modulate the chemistry of those compounds (e. g. in cycloaddition reactions) by appropriate tuning of their substitution (substituent type and position). 相似文献
10.
Study of a Novel Bisnaphthalimidopropyl Polyamine as Electroactive Material for Perchlorate‐selective Potentiometric Sensors 下载免费PDF全文
Renato Gil Célia G. Amorim Laura Crombie Paul Kong Thoo Lin Alberto Araújo Maria da Conceição Montenegro 《Electroanalysis》2015,27(12):2809-2819
In this work, the new polyamine bisnaphthalimidopropyl‐4,4’‐diaminodiphenylmethane is proposed as a new ionophore for perchlorate potentiometric sensors. The optimal formulation for the membrane comprised of 12 mmol kg?1 of the ionophore, and 68 % (w/w) of 2‐nitrophenyl phenyl ether as plasticizer and 31 % (w/w) of high molecular weight PVC. The sensors were soaked in water for a week to allow leakage of anionic impurities and for one day in a perchlorate solution (10?4 mol L?1) to improve reproducibility due to its first usage. The stability constant for the ionophore‐perchlorate association in the membrane, log βIL1=3.18±0.04, ensured a performance characterized by the slope of 54.1 (±0.7) mV dec?1 to perchlorate solutions with concentrations between 1.24×10?7 and 1.00×10?3 mol L?1. The sensors are insensitive to pH between 3.5 to 11.0, they have a practical detection limit of 7.66 (±0.42) ×10?8 mol L?1 and a response time below 60 s for solutions with perchlorate concentrations above 5×10?6 mol L?1. The accuracy of the results was confirmed by the analysis of the contaminant in a certified reference water sample. 相似文献