Trifunctional electron donor-donor-acceptor molecules are described in which photoinduced charge separation, D 2 -D 1 -A* f D 2 -D 1 + -A -, is followed by a charge migration step D 2 -D 1 + -A -(CS1) f D 2 + -D 1 -A -(CS2), leading to a relatively long-lived charge-separated state. The rate of the charge migration process could be determined in a range of solvents of low polarity. In benzene and dioxane, reversibility of the process allowed the determination of the free energy difference between CS1 and CS2. The relative energy of the CS2 state is much lower than expected from simple electrostatic models. An increase of the charge migration rate was found with increasing solvent polarity within a series of alkyl ethers or alkyl acetates. However, an apparent preferential stabilization of the CS1 state in acetates relative to ethers leads to discontinuities in the solvatochromic shift behavior of the CT fluorescence from the CS1 state, and in the increase of the charge migration rate as a function of dielectric constant. In a reference compound lacking the intermediate redox unit, direct long-range charge separation yielding a D 2 + -bridge-A -charge-separated state can occur, but the yield is significantly lower than in the triads.
Reversible charge migration in the excited state of an electron Donor-Donor-Acceptor system detected via delayed charge transfer fluorescence Willemse, R.J.; Verhoeven, J.W.; Brouwer, A.M.
Disclaimer/Complaints regulationsIf you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: http://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.