Photoionization of the chiral molecule glycidol has been investigated in the valence region. Photoelectron circular dichroism (PECD) curves have been obtained at various photon energies by using circularly polarized VUV synchrotron radiation and a velocity map imaging technique to record angle-resolved photoelectron spectra (PES). The measured chiral asymmetries vary dramatically with the photon energy as well as with the ionized orbital, improving the effective orbital resolution of the PECD spectrum with respect to the PES. Typical asymmetry factors of 5% are observed, but the peak values measured range up to 15%. The experimental results are interpreted by continuum multiple scattering (CMS-Xalpha) calculations for several thermally accessible glycidol conformers. We find that a nearly quantitative agreement between theory and experiments can be achieved for the ionization of several molecular orbitals. Owing to the sensitivity of PECD to molecular conformation this allows us to identify the dominant conformer. The influence of intramolecular hydrogen bond orbital polarization is found to play a small yet significant role in determining the chiral asymmetry in the electron angular distributions.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1039/b714095a | DOI Listing |
Sci Total Environ
January 2025
US Department of Agriculture, Agriculture Research Service, Hydrology and Remote Sensing Laboratory, Beltsville, MD, United States of America.
Metolachlor is the most heavily used member of acetanilide herbicides, which are noted for forming highly soluble metabolites in root zone soils soon after field application. The two primary metabolites of metolachlor, metolachlor ethane sulfonic acid (MESA) and metolachlor oxanilic acid (MOXA), retain the same chiral chemistry as their source and are important tracers of nitrate loading from agricultural cropland. New analytical methods for separating the isomers of MESA and MOXA, enable studies assessing changes in the abundance of atropisomer pairs of the carbon chiral enantiomers in environmental samples.
View Article and Find Full Text PDFMater Horiz
January 2025
Key Laboratory of Bio-based Material Science and Technology of Ministry of Education, Northeast Forestry University, Harbin 150040, China.
Dynamic responsive structural colored materials have drawn increased consideration in a wide range of applications, such as colorimetric sensors and high-safety tags. However, the sophisticated interactions among the individual responsive parts restrict the advanced design of multimodal responsive photonic materials. Inspired by stimuli-responsive color change in chameleon skin, a simple and effective photo-crosslinking strategy is proposed to construct hydroxypropyl cellulose (HPC) based hydrogels with multiple responsive structured colors.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States.
Precisely controlling quantum states is relevant in next-generation quantum computing, encryption, and sensing. Chiral organic chromophores host unique light-matter interactions, which allow them to manipulate the quantized circular polarization of photons. Axially chiral organic scaffolds, such as helicenes or twisted acenes, are powerful motifs in chiral light manipulation.
View Article and Find Full Text PDFRSC Adv
January 2025
Department of Organic Chemistry, University of Debrecen Egyetem Square 1 Debrecen 4032 Hungary
Domino Knoevenagel-cyclization reactions of styrene substrates, containing an -(-formyl)aryl subunit, were carried out with -substituted 2-cyanoacetamides to prepare tetrahydro-4-pyrano[3,4-]quinolone and hexahydrobenzo[]phenanthridine derivatives by competing IMHDA and IMSDA cyclization, respectively. The diastereoselective IMHDA step with α,β-unsaturated amide, thioamide, ester and ketone subunits as a heterodiene produced condensed chiral tetrahydropyran or thiopyran derivatives, which in the case of Meldrum's acid were reacted further with amine nucleophiles in a multistep domino sequence. In order to simplify the benzene-condensed tricyclic core of the targets and get access to hexahydro-1-pyrano[3,4-]pyridine derivatives, a truncated substrate was reacted with cyclic and acyclic active methylene reagents in diastereoselective Knoevenagel-IMHDA reactions to prepare novel condensed heterocyclic scaffolds.
View Article and Find Full Text PDFPest Manag Sci
January 2025
College of Materials and Chemistry and School of Plant Protection, Anhui Agricultural University, Hefei, China.
Background: Development of novel chiral antifungal agents for effective control of plant pathogens is urgently needed. In this study, a series of pyrazol-5-yl-benzamide derivatives containing chiral oxazoline moiety were rationally designed and developed based on molecular docking.
Results: The in vitro antifungal assay results indicated that compounds (rac)-4h (R = Et), (S)-4 h (R = S-Et) and (R)-4 h (R = R-Et) exhibited remarkable antifungal activities against Valsa mali with median effective concentration (EC) values of 0.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!