Enhancement of the σ-hole on the halogen atom of aryl halides due to perfluorination of the ring is demonstrated by use of the Extended Townes-Dailey (ETD) model coupled to a Natural Atomic Orbital Bond analysis on two perfluorinated aryl halides (CFCl and CFBr) and their hydrogenated counterparts. The ETD analysis, which quantifies the halogen p-orbitals populations, relies on the nuclear quadrupole coupling constants which in this work are accurately determined experimentally from the rotational spectra. The rotational spectra investigated by Fourier-transform microwave spectroscopy performed in supersonic expansion are reported for the parent species of CFCl and CFBr and their C, Cl or Br substituted isotopologues observed in natural abundance. The experimentally determined rotational constants combined with theoretical data at the MP2/aug-cc-pVTZ level provide precise structural information from which an elongation of the ring along its symmetry axis due to perfluorination is proved.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1039/d1cp03023j | DOI Listing |
J Am Chem Soc
December 2024
Department of Chemistry, University of Washington, Seattle, Washington 98195, United States.
Hydroalkylation of terminal alkynes is a powerful approach to the synthesis of disubstituted alkenes. However, its application is largely unexplored in the synthesis of α,β-unsaturated carbonyls, which are common among synthetic intermediates and biologically active molecules. The thermodynamically less stable -isomers of activated alkenes have been particularly challenging to access because of their propensity for isomerization and the paucity of reliable -selective hydroalkylation methods.
View Article and Find Full Text PDFOrg Lett
December 2024
Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, College of Chemistry & Materials Science, Northwest University, Xi'an 710127, People's Republic of China.
Metal-catalytic conversion of polysulfide reagents is a major challenge in organic synthesis due to its challenging activation modes of multiple S-S bonds. The utilization of aryl di- and trithiosulfonates in nickel-catalyzed reductive coupling with aryl halides has been unexplored. Herein, we unprecedentedly describe PPh and Zn-collaborative reduction-induced nickel-catalytic selective C-S coupling of aryl di/trithiosulfonates with aryl halides to access sulfides over common disulfides or trisulfides.
View Article and Find Full Text PDFChem Asian J
December 2024
IOCB CAS: Ustav organicke chemie a biochemie Akademie ved Ceske republiky, Chemistry, 16000, CZECHIA.
Single-atom-based Metal-Organic Frameworks (MOFs) hold great promising candidates for heterogeneous catalysis, demonstrating outstanding catalytic activity and exceptional product selectivity. This is attributed to their optimal atom utilization, high surface energy, and the presence of unsaturated coordination environments. Here in, we have developed a nickel single-atom catalyst (UiO-66/Ni) featuring Ni single atoms covalently attached to defect-engineered Zr-oxide clusters within the stable UiO-66 framework, synthesized via a straightforward solution impregnation method.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
University of Minnesota Twin Cities College of Science and Engineering, Chemical Engineering and Materials Science, 421 Washington Ave SE, 55455, Minneapolis, UNITED STATES OF AMERICA.
We report the development of a small molecule-based barcoding platform for pooled screening of nanoparticle delivery. Using aryl halide-based tags (halocodes), we achieve high-sensitivity detection via gas chromatography coupled with mass spectrometry or electron capture. This enables barcoding and tracking of nanoparticles with minimal halocode concentrations and without altering their physicochemical properties.
View Article and Find Full Text PDFMacromol Rapid Commun
December 2024
State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, China.
The development of high activity catalysts is crucial for improving industrial efficiency and mitigating environmental pollution. Polyisocyanides, with their pendant groups capable of forming ordered adjacent structures, offer a promising framework for designing cooperative catalysts that mimic the functionality of bimetallic centers. This unique structural arrangement is anticipated to significantly enhance catalytic activity in cooperative reactions.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!