Push-pull molecules bearing a hydrazonocyclopentadiene acceptor moiety: from the synthesis to organic photovoltaic applications

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Use of hop cone extract obtained under supercritical CO2 conditions for producing antibacterial all-purpose cleaners

This paper attempts to demonstrate empirically the possibility of using a hydrophobic extract of hop cone obtained under the conditions of supercritical carbon dioxide to produce all-purpose cleaner with antimicrobial activity and low irritant potential. A series of prototypes of products varied by the extract concentration was developed. The formulations were assessed for physicochemical properties: particle size, turbidity, and color. The results indicate that the hydrophobic extracts of hop cone can be a valuable component of chemical products intended for washing, having a broad spectrum of action and contributing to improvement of the product’s safety.     

Study of the Electron Density in an Inductively Coupled Plasma of Fluorine-Hydrogen-Argon Gas Mixture

Plasma Chemistry and Plasma Processing - In this paper, we present the results of non-contact measurements of electron density in an inductively coupled chemically active plasma at a pressure of...     

Influence of the Intramolecular Hydrogen Bond on the Fluorescence of 2-ortho-Aminophenyl Pyridines

The dynamic nature of excited-state intramolecular proton transfer (ESIPT) and its effect on emission spectra is an attractive strategy to create multi-emissive dyes. Here we describe the behavior of a series of hydrogen-bonded triphenylpyridines with a set of donor–acceptor combinations that allowed us to perceive the influence of each substitution on the photophysical properties of the dyes. The susceptibility of these ESIPT moieties to pH variations was also studied, elucidating that the level of protonation had a significant effect on the emission color. The assignment of each emission band was made by using DFT and td-DFT calculations that were in agreement with the experimental results. This study emphasizes the versatility of triphenylpyridines that can be synthesized effortlessly with a logical and independent C-2, C-4 and C-6 substitution in order to have the desired ESIPT modulation and subsequent multi-emission response.     

1,1‐Ethenediol: The Long Elusive Enol of Acetic Acid

We present the first spectroscopic identification of hitherto unknown 1,1‐ethenediol, the enol tautomer of acetic acid. The title compound was generated in the gas phase through flash vacuum pyrolysis of malonic acid at 400 °C. The pyrolysis products were subsequently trapped in argon matrices at 10 K and characterized spectroscopically by means of IR and UV/Vis spectroscopy together with matching its spectral data with computations at the CCSD(T)/cc‐pCVTZ and B3LYP/6–311++G(2d,2p) levels of theory. Upon photolysis at λ=254 nm, the enol rearranges to acetic acid and ketene.     

A Unified Experimental/Theoretical Description of the Ultrafast Photophysics of Single and Double Thionated Uracils

Photoinduced processes in thiouracil derivatives have lately attracted considerable attention due to their suitability for innovative biological and pharmacological applications. Here, sub-20 fs broadband transient absorption spectroscopy in the near-UV are combined with CASPT2/MM decay path calculations to unravel the excited-state decay channels of water solvated 2-thio and 2,4-dithiouracil. These molecules feature linear absorption spectra with overlapping ππ* bands, leading to parallel decay routes which we systematically track for the first time. The results reveal that different processes lead to the triplet states population, both directly from the ππ* absorbing state and via the intermediate nπ* dark state. Moreover, the 2,4-dithiouracil decay pathways is shown to be strongly correlated either to those of 2- or 4-thiouracil, depending on the sulfur atom on which the electronic transition localizes.     

Oscillation of Functions in the Hölder Class

Potential Analysis - We study the size of the set of points where the α-divided difference of a function in the Hölder class Λα is bounded below by a fixed positive constant....