The UPS spectra of six hydrocarbon cage compounds have been investigated by a Green-function approach in conjunction with a full harmonic treatment of vibrational modulation effects. The remarkable agreement with experimental results points out the reliability of the proposed computational approach and the strong interplay of stereoelectronic and vibrational effects in tuning the overall spectra.
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http://dx.doi.org/10.1021/acs.jctc.0c00645 | DOI Listing |
Acc Chem Res
January 2024
Mulliken Center for Theoretical Chemistry, Beringstraße 4, D-53115 Bonn, Germany.
ConspectusAlkanes play a pivotal role in industrial, environmental, and biological processes. They are characterized by their carbon-carbon single-bond structure, remarkable stability, and conformational diversity. Fluorination of such compounds imparts unique physicochemical properties that often enhance pharmacokinetic profiles, metabolic stability, and receptor interactions while keeping beneficial properties.
View Article and Find Full Text PDFInorg Chem
July 2022
Department of Chemistry and Centre for Advance Studies in Chemistry, Panjab University, Chandigarh 160014, India.
Five new mononuclear lanthanide complexes, [LnL][EtNH]·THF/HO (Ln = Nd, Tb, Dy) (HL = 2-bis(2-hydroxy-3,5-dichloro benzyl)aminomethyl]pyridine), Ln = Nd (), Tb (), and Dy (), and (HL = 2-bis(2-hydroxy-3,5-dibromo benzyl)aminomethyl]pyridine), Ln = Nd (, HO) and Tb (), were synthesized and structurally characterized by single-crystal X-ray diffraction analyses. Being isostructural in all the five cases, the metal center is octa-coordinated with a triangular dodecahedron ( symmetry) geometry, and it is independent of the halogen substitution (Cl/Br). This close similarity is due to the composite interplay of hydrogen/halogen bond interactions that control the overall crystal packing, yet notable differences in association patterns among the individual ones arise from the subtle stereo-electronic requirement of individual molecules in the three-dimensional (3D) architecture.
View Article and Find Full Text PDFChem Soc Rev
September 2021
N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky prosp., 119991 Moscow, Russian Federation.
Understanding the interplay of multiple components (steric, electrostatic, stereoelectronic, dispersive, ) that define the overall energy, structure, and reactivity of organic molecules can be a daunting task. The task becomes even more difficult when multiple approaches based on different physical premises disagree in their analysis of a multicomponent molecular system. Herein, we will use a classic conformational "oddity", the anomeric effect, to discuss the value of identifying the key contributors to reactivity that can guide chemical predictions.
View Article and Find Full Text PDFJACS Au
February 2021
Institute of Systems and Physical Biology, Shenzhen Bay Laboratory, Shenzhen 518055, China.
Carbon dioxide capture, corresponding to the recombination process of decarboxylation reactions of organic acids, is typically barrierless in the gas phase and has a relatively low barrier in aprotic solvents. However, these processes often encounter significant solvent-reorganization-induced barriers in aqueous solution if the decarboxylation product is not immediately protonated. Both the intrinsic stereoelectronic effects and solute-solvent interactions play critical roles in determining the overall decarboxylation equilibrium and free energy barrier.
View Article and Find Full Text PDFChem Sci
May 2020
Department of Chemistry and Biochemistry, Florida State University Tallahassee Fl 32306 USA
We address this question by exploring the interplay between the primary and secondary stereoelectronic effects in the Baeyer-Villiger (BV) rearrangement by experimental and computational studies of γ-OR-substituted γ-peroxylactones, the previously elusive non-strained Criegee intermediates (CI). These new cyclic peroxides were synthesized by the peroxidation of γ-ketoesters followed by cyclization using a BF·EtO/HO system. Although the primary effect (alignment of the migrating C-R bond with the breaking O-O bond) is active in the 6-membered ring, weakening of the secondary effect (donation from the OR lone pair to the breaking C-R bond) provides sufficient kinetic stabilization to allow the formation and isolation of stable γ-hydroperoxy-γ-peroxylactones with a methyl-substituent in the C6-position.
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