Abstract
DNA hairpins having both a tethered anthraquinone (Aq) end-capping group and a perylenediimide (PDI) base surrogate were synthesized, wherein Aq and PDI are each separated from a G-C base pair hole trap by A-T and I-C base pairs (G = guanine, A = adenine, T= thymine, C = cytosine, I = inosine). Selective photoexcitation of PDI at 532 nm generates a singlet radical ion pair (RP), 1(G+•-PDI-•), while selective photoexcitation of Aq at 355 nm generates the corresponding triplet RP, 3(G+•-Aq-•). Subsequent radical pair intersystem crossing within these spin-correlated RPs leads to mixed spin states that exhibit spin-polarized, time-resolved EPR spectra in which the singlet- and triplet-initiated RPs have opposite phases. These results demonstrate that a carefully designed DNA hairpin can serve as a photodriven molecular spin switch based on wavelength-selective formation of the singlet or triplet RP without significant competition from undesired energy transfer processes.
Original language | English (US) |
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Pages (from-to) | 10970-10973 |
Number of pages | 4 |
Journal | Journal of the American Chemical Society |
Volume | 135 |
Issue number | 30 |
DOIs | |
State | Published - Jul 31 2013 |
ASJC Scopus subject areas
- General Chemistry
- Biochemistry
- Catalysis
- Colloid and Surface Chemistry