Herein, we disclose cyclic(alkyl)(amino)carbenes (CAACs) to be one-electron reductants under the formation of a transient radical cation as indicated by EPR spectroscopy. The disclosed CAAC reducing reactivity was used to synthesize acyclic(amino)(aryl)carbene-based Thiele and Chichibabin hydrocarbons, a new class of Kekulé diradicaloids. The results demonstrate CAACs to be potent organic reductants. Notably, the acyclic(amino)(aryl)carbene-based Chichibabin's hydrocarbon shows an appreciable population of the triplet state at room temperature, as evidenced by both variable-temperature NMR and EPR spectroscopy.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9321839 | PMC |
http://dx.doi.org/10.1002/chem.202104567 | DOI Listing |
Environ Sci Technol
January 2025
Zachry Department of Civil & Environmental Engineering, Texas A&M University, College Station, Texas 77843, United States.
This study quantifies the contribution of the HO-dependent pathway to hydroxyl radical (OH) production from the photolysis of dissolved organic matter (DOM). OH formation rates were cross-validated using benzoate and terephthalate as probe compounds for diverse DOM sources (reference isolates and whole waters). Catalase addition revealed that the HO-dependent pathway accounts for 10-20% of the total OH production in DOM isolate materials, but no significant correlation was observed between ambient iron (Fe) concentrations and HO-dependent OH formation.
View Article and Find Full Text PDFNat Chem
January 2025
School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington, New Zealand.
Benzene reduction by molecular complexes remains an important synthetic challenge, requiring harsh reaction conditions involving group I metals. Reductions of benzene, to date, typically result in a loss of aromaticity, although the benzene tetra-anion, a 10π-electron system, has been calculated to be stable and aromatic. Due to the lack of sufficiently potent reductants, four-electron reduction of benzene usually requires the use of group I metals.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Group of Coordination Chemistry, Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
Lanthanide redox reactivity remains limited to one-electron transfer reactions due to their inability to access a broad range of oxidation states. Here, we show that multielectron reductive chemistry is achieved for ytterbium by using the tripodal tris(siloxide)arene redox-active ligand, which can store two electrons in the arene anchor. Reduction of the Yb(III) complex of the tris(siloxide)arene tripodal ligand affords the Yb(II) analogue by metal-centered reduction.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, 741246, India.
An established concept to create radical intermediates is photoexcitation of a catalyst to a higher energy intermediate, subsequently leading to a photoinduced electron transfer (PET) with a reaction partner. The known concept of consecutive photoinduced electron transfer (con-PET) leads to catalytically active species even higher in energy by the uptake of two photons. Generally speaking, increased photon uptake leads to a more potent reductant.
View Article and Find Full Text PDFBiochemistry
December 2024
Department of Chemistry and Biochemistry, Loyola University Chicago, 1068 W Sheridan Rd, Chicago, Illinois 60660, United States.
Dihydroorotate dehydrogenases (DHODs) catalyze the transfer of electrons between dihydroorotate and specific oxidant substrates. Class 1B DHODs (DHODBs) use NAD as the oxidant substrate and have a heterodimeric structure that incorporates two active sites, each with a flavin cofactor. One FeS center lies roughly equidistant between the flavin isoalloxazine rings.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!