{"title":"Exploring the Helical Structure of Ethylene Oxides: Beyond Steric and Related Effects.","authors":"Matheus P Freitas","doi":"10.1002/cphc.202500458","DOIUrl":null,"url":null,"abstract":"<p><p>Dimethoxyethane (DME) is the monomer of polyethylene oxide, a polymer widely used in materials science, with its conformation affecting properties such as host-guest interactions with ions. This quantum-chemical study reveals that DME undergoes rotational isomerization among nine rotamers, favoring a zigzag (all-trans) conformation, followed by a conformer with the OCCO fragment in a gauche arrangement. This preference strengthens with increasing chain length but transitions to a gauche configuration resembling a helical structure in polar solvents like DMSO. Unlike expectations based on steric effects or earlier assumptions of a 1,5 CH<sub>3</sub>/O nonbonding attraction, the helical structure arises from reduced dipolar repulsion/dipole stabilization and hyperconjugative interactions that surpass Lewis-type interactions. The helical structure of a 21-heavy-atom oligomer further compresses to encapsulate a potassium cation, forming a highly stable complex.</p>","PeriodicalId":9819,"journal":{"name":"Chemphyschem","volume":" ","pages":"e2500458"},"PeriodicalIF":2.2000,"publicationDate":"2025-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Chemphyschem","FirstCategoryId":"92","ListUrlMain":"https://doi.org/10.1002/cphc.202500458","RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
引用次数: 0
Abstract
Dimethoxyethane (DME) is the monomer of polyethylene oxide, a polymer widely used in materials science, with its conformation affecting properties such as host-guest interactions with ions. This quantum-chemical study reveals that DME undergoes rotational isomerization among nine rotamers, favoring a zigzag (all-trans) conformation, followed by a conformer with the OCCO fragment in a gauche arrangement. This preference strengthens with increasing chain length but transitions to a gauche configuration resembling a helical structure in polar solvents like DMSO. Unlike expectations based on steric effects or earlier assumptions of a 1,5 CH3/O nonbonding attraction, the helical structure arises from reduced dipolar repulsion/dipole stabilization and hyperconjugative interactions that surpass Lewis-type interactions. The helical structure of a 21-heavy-atom oligomer further compresses to encapsulate a potassium cation, forming a highly stable complex.
期刊介绍：
ChemPhysChem is one of the leading chemistry/physics interdisciplinary journals (ISI Impact Factor 2018: 3.077) for physical chemistry and chemical physics. It is published on behalf of Chemistry Europe, an association of 16 European chemical societies.
ChemPhysChem is an international source for important primary and critical secondary information across the whole field of physical chemistry and chemical physics. It integrates this wide and flourishing field ranging from Solid State and Soft-Matter Research, Electro- and Photochemistry, Femtochemistry and Nanotechnology, Complex Systems, Single-Molecule Research, Clusters and Colloids, Catalysis and Surface Science, Biophysics and Physical Biochemistry, Atmospheric and Environmental Chemistry, and many more topics. ChemPhysChem is peer-reviewed.
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