Dual Photochemical Bond Cleavage for a Diarylethene-Based Phototrigger Containing both Methanolic and Acetic Sources

• DOI: 10.1021/acs.joc.6b02256
• Publication Date: 2016-10-14T20:40:16Z
• Authors: Olivier Galangau; Stéphanie Delbaere; Nicolas Ratel-Ramond; Gwénaël Rapenne; Ruiji Li; Jan Patrick Dela ...; Takuya Nakashima; Tsuyoshi Kawai
• Keywords: Ions; Proof of principles; Dft calculation; Mechanistic aspects; 01 natural sciences; bond cleavages; Chemical group; chemical bonds; 0104 chemical sciences; [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry; Different solvents; Td-dft calculations; Density functional theory; Non-covalent interaction

In this paper, we present a novel concept for "smarter" photolabile organic compounds combining not one but two caged functions. As proof of principle, this diarylethene-based compound possesses two inhibited chemical groups (OMe and OAc) and its efficient release in different solvents is reported. In low- to medium-polarity media, both MeOH and AcOH are released, with a slight preferential uncaging of AcOH except in 1,4-dioxane, where MeOH is preferentially released. In contrast, DMSO or DMF render AcOH release strongly dominating. DFT calculations of the corresponding photoreactive conformations not only afford strong support to the observed release of MeOH and AcOH but also qualitatively explain the preferential release of acid in terms of dispersive noncovalent interactions. Finally, mechanistic aspects are discussed on the bases of the spectroscopic observations and of the TD-DFT calculations.