Toward Organic Photohydrides: Excited-State Behavior of 10-Methyl-9-phenyl-9,10-dihydroacridine
摘要:
The excited-state hydride release from 10methyl-9-phenyl-9,10-dihydroacridine (PhAcrH) was investigated using steady-state and time-resolved UV/vis absorption spectroscopy. Upon excitation, PhAcrH is oxidized to the corresponding iminium ion (PhAcr(+)), while the solvent (acetonitrile/water mixture) is reduced (52% of PhAcr(+) and 2.5% of hydrogen is formed). The hydride release occurs from the triplet excited state by a stepwise electron/hydrogen-atom transfer mechanism. To facilitate the search for improved organic photohydrides that exhibit a concerted mechanism, a computational methodology is presented that evaluates the thermodynamic parameters for the hydride ion, hydrogen atom, and electron release from organic hydrides.
Effects of Metal Ions on Physicochemical Properties and Redox Reactivity of Phenolates and Phenoxyl Radicals: Mechanistic Insight into Hydrogen Atom Abstraction by Phenoxyl Radical−Metal Complexes
complexes are also influenced by the metalions, depending on the Lewisacidity of the metalions. The phenoxyl radical complexes are successfully generated in situ by the oxidation of the phenolate complexes with (NH4)(2)[Ce4+(NO3)6] (CAN). They exhibited strong absorption bands around 400 nm together with a broad one around 600-900 nm, the latter of which is also affected by the metalions. The phenoxyl
activation energies of various hydridetransferreactions was developed according to transition state theory using the Morse-type free energy curves of hydride donors to release a hydride anion and hydrideacceptors to capture a hydride anion and by which the activation energies of 187 typical hydride self-exchange reactions and more than thirty thousand hydride cross transferreactions in acetonitrile were
Hydride-Transfer Reaction to a Mononuclear Manganese(III) Iodosylarene Complex
作者:Donghyun Jeong、Jaeheung Cho
DOI:10.1021/acs.inorgchem.1c00562
日期:2021.6.7
Metal iodosylarene species have received interest because of their potential oxidative power as a catalyst. We present the first example of hydride-transfer reactions to a mononuclearmanganese(III) iodosylbenzene complex, [MnIII(TBDAP)(OIPh)(OH)]2+ (1; TBDAP = N,N-di-tert-butyl-2,11-diaza[3.3](2,6)pyridinophane), with dihydronicotinamide adenine dinucleotide (NADH) analogues. Kinetic studies show
Excited-State Hydroxide Ion Release From a Series of Acridinol Photobases
作者:Yun Xie、Stefan Ilic、Sanja Skaro、Veselin Maslak、Ksenija D. Glusac
DOI:10.1021/acs.jpca.6b10980
日期:2017.1.19
parameters that control the reaction barriers, the kinetics of excited-state OH– release from a series of acridinol photobases were studied using transient absorption spectroscopy. The rate constants were obtained in three solvents (methanol, butanol, and isobutanol), and the data were modeled using Marcustheory. The intrinsic reorganization energies obtained from these fits were found to correlate