Harnessing Proton-Coupled Electron Transfer for Hydrogenation of Aza-Arenes: Photochemistry of Quinoxaline Derivatives in Methanol.

ABSTRACT: Three quinoxaline derivatives are investigated both experimentally and theoretically to assess their ability for the methanol oxidation and harvesting of hydrogen. In inert solvents, the nonplanar compounds exhibit very weak fluorescence from the lowest excited singlet state, whereas the planar and rigid chromophore emits non-Kasha fluorescence from the S₂(ππ*) state despite the proximity of the S₁(nπ*) state. In methanol, hydrogen-bonded complexes with solvent molecules are formed, and in all chromophores, the lowest singlet state is populated after excitation of the S₂(ππ*) state. The switch from non-Kasha emission of the planar compound in inert solvents to regular emission in methanol is related to reduced symmetry of the hydrogen-bonded complex with me

SUBMITTER: Morawski OW 

PROVIDER: S-EPMC10614181 | biostudies-literature | 2023 Oct

REPOSITORIES: biostudies-literature