Theoretical Insights Into the Excited State Double Proton Transfer Mechanism of Deep Red Pigment Alkannin

As the most important component of deep red pigments, alkannin is investigated theoretically in detail based on time-dependent density functional theory (TDDFT) method. Exploring the dual intramolecular hydrogen bonds (O1–H2···O3 and O4–H5···O6) of alkannin, we confirm the O1–H2···O3 may play a more important role in the first excited state than the O4–H5···O6 one. Infrared (IR) vibrational analyses and subsequent charge redistribution also support this viewpoint. Via constructing the S₁-state potential energy surface (PES) and searching transition state (TS) structures, we illuminate the excited state double proton transfer (ESDPT) mechanism of alkannin is the stepwise process that can be first launched by the O1–H2···O3 hydrogen bond wire in gas state, acetonitrile (CH₃CN) and cyclohexane (CYH) solvents. We present a novel mechanism that polar aprotic solvents can contribute to the first-step proton transfer (PT) process in the S₁ state, and nonpolar solvents play important roles in lowering the potential energy barrier of the second-step PT reaction

Phylogenetic relationship of <i>Cryptosporidium</i> parasites inferred by neighbor-joining analysis of the SSU rRNA based on evolutionary distances calculated using the Kimura two-parameter model.

<p>Bootstrap values were obtained using 1,000 pseudoreplicates.</p

Theoretical explorations about solvent polarity associated excited state proton transfer behaviour for 2-benzoxazol-2-yl-6-triethylsilanylethynyl-phenol fluorophore

As is known, novel organic molecules with amazing characteristics of excited-state intramolecular proton transfer (ESIPT) have become a hot and fascinating topic. Herein, our main attention is to investigate the dynamic behaviour of 2-benzoxazol-2-yl-6-triethylsilanylethynyl-phenol (BYTP), an intriguing derivative derived from 2-(2-hydroxyphenyl)benzoxazole (HBO). Dependent on examining four different aprotic solvents with varying levels of polarity, we can confirm without a doubt that solvent polarity has a big impact on the way hydrogen bonding interactions, redistribution as well as reorganisation of charge, and associated ESIPT phenomena occur when light is involved. After carefully comparing and accurately measuring reaction barriers in different solvent environments, our groundbreaking findings strongly suggest that highly polar solvents are good at helping the ESIPT reaction for BYTP fluorophore happen. We really hope that this study can give us some insight into how BYTP behaves when it's excited and influenced by solvent polarity, while also opens up possibilities for future research and applications involving other new HBO derivatives.</p

An Introduction to ATLAS Pixel Detector DAQ and Calibration Software Based on a Year's Work at CERN for the Upgrade from 8 to 13 TeV

An overview is presented of the ATLAS pixel detector Data Acquisition (DAQ) system obtained by the author during a year-long opportunity to work on calibration software for the 2015-16 Layer‑2 upgrade. It is hoped the document will function more generally as an easy entry point for future work on ATLAS pixel detector calibration systems. To begin with, the overall place of ATLAS pixel DAQ within the CERN Large Hadron Collider (LHC), the purpose of the Layer-2 upgrade and the fundamentals of pixel calibration are outlined. This is followed by a brief look at the high level structure and key features of the calibration software. The paper concludes by discussing some difficulties encountered in the upgrade project and how these led to unforeseen alternative enhancements, such as development of calibration “simulation” software allowing the soundness of the ongoing upgrade work to be verified while not all of the actual readout hardware was available for the most comprehensive testing

Correlations between the IMD, its Domains, with rates of smoking and household poverty.

<p>Correlations between the IMD, its Domains, with rates of smoking and household poverty.</p

Weights for ranked health indicators in the Health Domain.

<p>Weights for ranked health indicators in the Health Domain.</p

Developing the IMD: An overview.

<p>Adapted from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0181260#pone.0181260.g002" target="_blank">Fig 2</a> SIMD 2012 Methodology, in Scottish Index of Multiple Deprivation 2012. Edinburgh: Scottish Government (Crown Copyright 2012, See <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0181260#pone.0181260.s001" target="_blank">S1 Fig</a>). [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0181260#pone.0181260.ref036" target="_blank">36</a>] Reproduced with Permission (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0181260#pone.0181260.s002" target="_blank">S1 File</a>)</p

Solvation effect on photophysical properties and ESIPT behaviours for 2-benzooxazol-2-yl-6-thiophen-2-yl-phenol fluorophore: a theoretical study

Inspired by its potential applications of organic luminescence and fluorescence probe materials for 2-(2′-hydroxyphenyl)benzazoles (HBX) derivatives, this study mainly investigates the excited-state behaviours of a novel 2-benzooxazol-2-yl-6-thiophen-2-yl-phenol (BYTYP) fluorophore. Theoretical exploration has been conducted on the solvent-dependent interactions of excited-state intramolecular hydrogen bonding and the process of excited-state intramolecular proton transfer (ESIPT) for BYTYP. By combining optimised geometrical modifications, infrared (IR) vibrational spectra and the core-valence bifurcation (CVB) index, hydrogen bonding strengthening can be confirmed. Predicting the bond energy (EHB), we assert that nonpolar solvents are more conducive to enhancing hydrogen bonding interactions. The ESIPT tendency of BYTYP is further elucidated by charge reorganisation resulting from photoexcitation. By exploring potential energy surfaces (PESs) and identifying transition states (TS), we have uncovered the solvent-polarity-controlled ESIPT behaviours. We hope these insights into excited-state dynamics will facilitate the design and development of novel fluorescent sensors in future.</p

Weights of ranked education indicators in the Education Domain.

<p>Weights of ranked education indicators in the Education Domain.</p

Friedel–Crafts-Type Allylation of Nitrogen-Containing Aromatic Compounds with Allylic Alcohols Catalyzed by a [Mo₃S₄Pd(η³-allyl)] Cluster

With the direct use of allylic alcohols as allylating agents, the Friedel–Crafts-type allylic alkylation of nitrogen-containing aromatic compounds catalyzed by a [Mo₃S₄Pd­(η³-allyl)] cluster is achieved. With a 3 mol % catalyst loading in acetonitrile at reflux or 60 °C, a variety of <i>N</i>,<i>N</i>-dialkylanilines and indoles reacted smoothly with allylic alcohols to afford the Friedel–Crafts-type allylation products in good to excellent yields with high levels of regioselectivity