133 research outputs found
Microwave-assisted palladium-catalyzed C–C coupling versus nucleophilic aromatic substitution of hydrogen (S N H ) in 5-bromopyrimidine by action of bithiophene and its analogues
A Potassium Metal-Organic Framework based on Perylene- 3,4,9,10-tetracarboxylate as Sensing Layer for Humidity Actuators
We have synthesized a novel three-dimensional metal-organic-framework (MOF) based on the
perylene-3,4,9,10-tetracarboxylate linker and potassium as metallic centre. We report the formation
of this K-based MOF using conventional routes with water as solvent. This material displays intense
green photoluminescence at room temperature, and displays an aggregation dependent quenching.
Correlation of the optical properties with the crystalline packing was confirmed by DFT calculations. We
also demonstrate its potential to build humidity actuators with a reversible and reproducible response,
with a change of 5 orders of magnitudes in its impedance at about 40% relative humidity (RH). This
3D-MOF is based on an interesting perylene derivative octadentate ligand, a moiety with interesting
fluorescent properties and known component in organic semiconductors. To the best of our knowledge,
this is the first time to build such a printed and flexible actuator towards humidity with a reversible
response, enabling precise humidity threshold monitoring.This work was supported by the Junta de Andalucía (FQM-1484, and FQM-195). Red Guipuzcoana de Ciencia,
Tecnología e Innovación (OF188/2017) and University of the Basque Country (GIU14/01, EHUA16/32). BB
acknowledges funding by RyC-2012–10381 contract and computational resources provided by the RES and
Alhambra supercomputing facilities. This work was also supported by the German Research Foundation (DFG)
and the Technical University of Munich within the Open Access Publishing Funding Programme
Stable σH-adducts in the reactions of the acridinium cation with heterocyclic N-nucleophiles
Aromatic nucleophilic substitution (SNAr) Reactions of 1,2- and 1,4-halonitrobenzenes and 1,4-dinitrobenzene with carbanions in the gas phase
Efficiency of Single Site Phase Transfer Catalyst in Free Radical Polymerization of Butyl Methacrylate - A Kinetic Study
Photoinduced Excited State Electron Transfer at Liquid/Liquid Interfaces
Several aspects of the photoinduced electron transfer (ET) reaction betweencoumarin 314 (C314) and N,N-dimethylaniline (DMA) at the water/DMA interface areinvestigated by molecular dynamics simulations. New DMA and water/DMA potentialenergy surfaces are developed and used to characterize the neat water/DMA interface.The adsorption free energy, the rotational dynamics and the solvation dynamics of C314at the liquid/liquid interface are investigated and are generally in reasonable agreementwith available experimental data. The solvent free energy curves for the ET reactionbetween excited C314 and DMA molecules are calculated and compared with thosecalculated for a simple point charge model of the solute. It is found that thereorganization free energy is very small when the full molecular description of the soluteis taken into account. An estimate of the ET rate constant is in reasonable agreement withexperiment. Our calculations suggest that the polarity of the surface “reported” by thesolute, as reflected by solvation dynamics and the reorganization free energy, is strongly solute-dependent
The occurrence of heat stress in central-west Poland
On the basis of term values (12 UTC) of meteorological data of seven synoptic stations in the central-west Poland heat stress index (HSI - Heat Stress Index) was calculated. During the year the heat stress of varying intensity occurred from February to November with a maximum in August. The rest of the year was dominated by thermoneutral conditions. In the period 1971-2006, and especially since 1999, becoming more frequent of occurrence days with an intensity of heat stress was so great, that pose a risk increase in body temperature (HSI > 100%). Based on the frequency of the occurrence of days with values HSI > 30% in the central-west Polad three areas with different number of days chargeable was distinguished
Evaluation of bio-thermal conditions in central-west Poland on the basis of subjective temperature (STI)
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