Benzyltrialkylgermane cation radicals were generated and spectroscopically characterized by nanosecond transient absorption spectroscopy. The germane cation radicals were found to rapidly react with nucleophiles (e.g., alcohols) in reactions that were first-order in cation radical and first-order in nucleophile. The geometries of the transition states for nucleophilic substitutions on benzyl-silane and -germane cation radicals were investigated by using the endocyclic restriction test. Cation radicals containing tethered nucleophiles that required endocyclic transition states with small angles between the bond being formed to the nucleophilic atom and the bond to the leaving group reacted ∼250 times more slowly than cation radicals with tethered nucleophiles where a large bond angle can be accommodated. The results are consistent with the nucleophile-assisted fragmentations proceeding through an inversion transition state.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/acs.joc.7b01892 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Metal oxides are promising catalysts for small molecule hydrogen chemistries, mediated by interfacial proton-coupled electron transfer (PCET) processes. Engineering the mechanism of PCET has been shown to control the selectivity of reduced products, providing an additional route for improving reductive catalysis with metal oxides. In this work, we present kinetic resolution of the rate determining proton-transfer step of PCET to a titanium-doped POV, TiVO(OCH) with 9,10-dihydrophenazine by monitoring the loss of the cationic radical intermediate using stopped-flow analysis.
View Article and Find Full Text PDFRadical-cation salts of BEDT-TTF with tris-coordinated racemic dysprosium(III) and terbium(III) anions.
Dalton Trans
January 2025
School of Science and Technology, Nottingham Trent University, Clifton Lane, Clifton, Nottingham, NG11 8NS, UK.
This paper reports the synthesis, crystal structures and conducting properties of the first BEDT-TTF radical-cation salts with symmetry tris-coordinated racemic lanthanide(III) anions. It is also the first crystallographic determination of the nine-coordinate tris(chelidonato)terbate and tris(chelidonato)dysprosate anions (chelidonic acid = clo = 4-oxo-4-pyran-2,6-dicarboxylic acid). Salt α-(BEDT-TTF)M(chelidonato)·EtOH·2HO is semimetallic for M = Tb, and semiconducting for M = Dy.
View Article and Find Full Text PDFTetra-Cationic Distibane Stabilized by Bis(α-iminopyridine) and Its Reactivity.
J Am Chem Soc
January 2025
Department of Chemistry, Indian Institute of Science Education and Research, Pune, Dr. Homi Bhabha Road, Pashan, Pune 411008, Maharashtra, India.
The work establishes the salt of a tetra-cationic distibane, [LSb][CFSO] = [][OTf] (CFSO = OTf), stabilized by a bis(α-iminopyridine) ligand , defying the Coulombic repulsion. The synthetic approach involved a dehydrocoupling reaction when a mixture of and Sb(OTf) in a 1:1 ratio was treated with EtSiH/LiBEtH as the hydride source. Compound [][OTf] was also achieved from [LSbCl][OTf] as a precursor and using EtSiH.
View Article and Find Full Text PDFMolecule-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 PDFMechanistic insight into multiple effects of copper ion on the photoreactivity of dissolved organic matter.
J Hazard Mater
January 2025
Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China.
Sunlight irradiation of dissolved organic matter (DOM) in surface water results in the production of photochemically produced reactive intermediates (PPRIs). This process is inevitably influenced by co-existing metal ions in aquatic environments; However, the underlying mechanism remains unclear. In this study, the effect of co-existing copper ion (Cu) on PPRIs produced by irradiation of DOM was systematically investigated, because Cu is a typical redox transient cation and has strong affinity to DOM.
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!