The anion radicals of alkoxy-substituted cyclooctatetraenes in hexamethylphosphoramide spontaneously dimerize to form the dianions of dialkoxy-[16]annulenes. The dianions reveal the expected high-field NMR resonance for the internal protons. After electron transfer, the EPR spectra of the corresponding anion radicals reveal that only the 1,5-dialkoxy systems are formed. Further, the measured proton and (13)C spin densities show that the odd electron resides in a molecular orbital with six hydrogens in "deep" nodal positions that completely hide them from EPR detection. This MO corresponds to the nonbonding (singly occupied) MO of higher energy after splitting of the degenerate nonbonding MOs by the two-electron-withdrawing substituents. The surprising electron-withdrawing nature of the alkoxy substituents is attributed to a rather strong mixing of the sigma and pi systems in [16]annulene.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/jo026806u | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Molecule-Based Proton-Electron Mixed Conductor with the Highest Ambipolar Conductivity.
J Am Chem Soc
January 2025
Division of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan.
Proton-electron mixed conductors (PEMCs) are an essential component for potential applications in hydrogen separation and energy conversion devices. However, the exploration of PEMCs with excellent mixed conduction, which is quantified by the ambipolar conductivity, σ = σσ/(σ + σ) (σ: electronic conductivity; σ: proton conductivity), is still a great challenge, largely due to the lack of structural characterization of both conducting mechanisms. In this study, we prepared a molecule-based proton-electron mixed-conducting cation radical salt, (ET)[Pt(pop)(Hpop)]·PhCN (ET: bis(ethylenedithio)tetrathiafulvalene, pop: PHO), by electrocrystallization.
View Article and Find Full Text PDFHigh performance ozone nanobubbles based advanced oxidation processes (AOPs) for degradation of organic pollutants under high pollutant loading.
J Environ Manage
January 2025
Department of Sanitary Engineering, Faculty of Civil and Environmental Engineering, Gdansk University of Technology, Narutowicza 11/12 Str., 80-233, Gdansk, Poland; School of Civil, Environmental, and Architectural Engineering, College of Engineering, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul, 02841, Republic of Korea. Electronic address:
Advanced Oxidation Processes (AOPs) have proven to be an effective solution for chemical wastewater treatment, particularly for degradation of organic pollutants, especially dyes. Ozonation is recognized as one of the most prevalent AOPs. Nevertheless, some cases show a lowered efficiency of O utilization which is attributed to its inadequate distribution in the treated water causing low residence time, low mass transfer coefficient as well as shorter half-life.
View Article and Find Full Text PDFSynthesis of Arsenocholine-Type Polycation Brush and Its Hydration Structure in Aqueous Solution.
Langmuir
January 2025
School of Advanced Engineering, Kogakuin University, Tokyo 192-0015, Japan.
Arsenocholine-containing methacrylate (MTAsB) inspired by marine organisms was synthesized by the reaction of 2-bromoethyl methacrylate and trimethylarsine to investigate its polymerization behavior and the fundamental properties of the resulting polymer. Controlled radical polymerization of MTAsB proceeded in the presence of a copper catalyst and imidazolium chloride at 60 °C for 8 h to give a water-soluble polycation with a 94% yield. The smaller amount of nonfreezing water and intermediate water of poly(MTAsB) was observed compared with that of the ammonium-containing polycations.
View Article and Find Full Text PDFEvaluation of Fenton-like reaction for sorption and degradation of kasugamycin in the presence of biochar.
Environ Geochem Health
January 2025
Institute of Soil and Environmental Sciences, Pir Mehr Ali Shah Arid Agriculture University, Rawalpindi, 46300, Pakistan.
Although the use of biochar as an adsorbent for the removal of various pollutants from wastewater is well established, the use of biochar/modified biochar for the scavenging of antibiotics from aqueous media in the Fenton-like system receives less attention. The highest kasugamycin (KSM) adsorption capacity (5.0 mg g) was obtained from the pristine biochar at the lowest initial pH of 3 in Fenton-like system.
View Article and Find Full Text PDFElectronic structure modulation of ultrathin PtRuMoCoNi high-entropy alloy nanowires for boosting peroxidase-like activity and sensitive colorimetric determination of isoniazid and hydrazine.
Mikrochim Acta
January 2025
Department of General Surgery, Hui Ya Hospital of The First Affiliated Hospital, Sun Yat-Sen University, Huizhou, 516081, Guangdong, China.
Self-supported ultrathin PtRuMoCoNi high-entropy alloy nanowires (HEANWs) were synthesized by a one-pot co-reduction method, whose peroxidase (POD)-like activity and catalytic mechanism were elaborated in detail. As expected, the PtRuMoCoNi HEANWs showed excellent POD-like activity. It can quickly catalyze the oxidization of colorless 3,3',5,5'-tetramethylbenzidine (TMB) to blue TMB through decomposition of HO to superoxide radicals.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!