Controlling reactivity by remote protonation of a basic side group in a bifunctional photoacid. Issue 24 (6th January 2016)

• Record Type: Journal Article
• Authors: Ditkovich, Julia; Pines, Dina; Pines, Ehud
• Is Part Of: Physical chemistry chemical physics. Volume 18:Issue 24(2016)
• Page Start: 16106
• Page End: 16115
• Publication Date: 2016-01-06
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/c5cp07672b
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : Ultrafast reactivity-switch is achieved by remote-protonation caused by protons diffusing from acidic to basic side-groups of bifunctional photoacids. Abstract : 6-Hydroxy-2-naphthoic acid and its sulfonate derivatives belong to a family of bifunctional photoacids where the –OH group acts as a proton donor and the –COO − group acts as a proton acceptor. Upon electronic excitation, the –OH group becomes more acidic and the –COO − group turns more basic. Change in the ionization state of one functional group causes a change (switch) in the reactivity of the other functional group. Using picosecond time-resolved and steady state spectroscopy, we find clear evidence for an ultrafast reactivity switch caused by a diffusional proton transfer through the water solvent between the two functional groups with no evidence of a concerted proton transfer.