The influence of resonance on the acidities of dimethyl sulfide (DMS), dimethyl sulfoxide (DMSO), and dimethyl sulfone (DMSO2) and their group 16 congeners (DMXO(n) for X = Se, Te, Po and n = 0-2) is examined using ab initio methods and the natural bond orbital (NBO) and natural resonance theory (NRT) analyses. Gas-phase acidities are evaluated using B3LYP-optimized geometries with coupled cluster energies and complete basis set extrapolation. The acidity of the DMSO(n) molecules increases with increasing coordination of the central S atom. Acidity also tends to increase when the central atom is substituted by a heavier group 16 atom. NRT analysis reveals significant resonance delocalization in the DMXO(n) molecules and their anions. On deprotonation, the DMXO(n) molecules undergo structural changes that are consistent with changes in the resonance character of the calculated charge densities. However, resonance cannot account for the trends in the deprotonation energies. Whereas the DMX- anions are more strongly resonance stabilized than their parent molecules DMX, the DMXO2(-) anions and DMXO2 molecules are nearly equally resonance stabilized. Thus, there appears to be no extra stabilization of DMXO2(-) compared to that of DMX- that would account for the enhanced acidity of DMXO2 relative to DMX.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/jp058010f | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Novel MRI-based Hyper-Fused Radiomics for Predicting Pathologic Complete Response to Neoadjuvant Therapy in Breast Cancer.
Acad Radiol
January 2025
Imaging Center, Harbin Medical University Cancer Hospital, Haping Road No.150, Nangang District, Harbin 150081, China (Q-X.C., L-Q.Z., X-Y.W., H-X.Z., J-J.L., M-C.X., H-Y.S., Z-X.K.). Electronic address:
Rationale And Objectives: To propose a novel MRI-based hyper-fused radiomic approach to predict pathologic complete response (pCR) to neoadjuvant therapy (NAT) in breast cancer (BC).
Materials And Methods: Pretreatment dynamic contrast-enhanced (DCE) MRI and ultra-multi-b-value (UMB) diffusion-weighted imaging (DWI) data were acquired in BC patients who received NAT followed by surgery at two centers. Hyper-fused radiomic features (RFs) and conventional RFs were extracted from DCE-MRI or UMB-DWI.
Development of an interactive ultra-high resolution magnetic resonance neurography atlas of the brachial plexus and upper extremity peripheral nerves.
Clin Imaging
January 2025
Hospital for Special Surgery, 535 East 70th Street, New York, NY 10021, United States of America. Electronic address:
Purpose: To develop an educational, interactive, ultra-high resolution, in vivo magnetic resonance (MR) neurography atlas for direct visualization of the brachial plexus and upper extremity.
Methods: A total of 16 adult volunteers without known peripheral neuropathy underwent magnetic resonance (MR) neurography of the brachial plexus and upper extremity. To improve vascular suppression, subjects received an intravenous infusion of ferumoxytol.
Spectral and molecular insights into the variations of dissolved organic matter in shallow groundwater impacted by surface water recharge.
Water Res
December 2024
State Key Laboratory of Environmental Criteria and Risk Assessment, and State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
Dissolved organic matter (DOM) represents one of the most active elements in aquatic systems, whose fraction is engaged in chemical and biological reactions. However, fluorescence, molecular diversity and variations of DOM in groundwater systems with the alteration of surface water recharge remain unclear. Herein, Excitation-emission matrix (EEM) fluorescence spectroscopy and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) combined with principal component coefficients, parallel factor analyses (PARAFAC) with two‒dimensional correlation spectroscopy (2D-COS) were applied in this study.
View Article and Find Full Text PDFElectrochemical sensors: Types, applications, and the novel impacts of vibration and fluid flow for microfluidic integration.
Biosens Bioelectron
January 2025
School of Engineering and Sciences, Tecnologico de Monterrey, Av. Eugenio Garza Sada, NL, 2501, Sur, 64849, Monterrey, Mexico; Department of Mechanical and Aerospace Engineering, University of California Irvine, Irvine, CA, 92697, USA.
Electrochemical sensors are part of a diverse and evolving world of chemical sensors that are impacted by high demand and ongoing technological advancements. Electrochemical sensors offer benefits like cost-efficiency, short response time, ease of use, good limit of detection (LOD) and sensitivity, and ease of miniaturization while providing consistent analytical results. These sensors are employed in various fields-such as healthcare and diagnostics, environmental monitoring, and the food industry-to detect bacteria, viruses, heavy metals, pesticides, and more.
View Article and Find Full Text PDFIrradiation and DOM mediate lead release from polyvinyl chloride microplastics in natural surface water.
J Hazard Mater
January 2025
State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China. Electronic address:
Polyvinyl chloride (PVC) is a widely used plastic, but the potential risk of heavy metal additive release from PVC microplastics (MPs) has not been fully explored. This study evaluates the release of lead (Pb) from recycled PVC MPs under natural conditions. The released Pb concentration in the dark was 1079.
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!