Photoselective DNA Hairpin Spin Switches
| Autor: | Arun K. Thazhathveetil, Frederick D. Lewis, Michael R. Wasielewski, Raanan Carmieli |
|---|---|
| Rok vydání: | 2013 |
| Předmět: |
Base Sequence
Light Guanine Base pair Lasers Inverted Repeat Sequences Temperature Nanotechnology DNA General Chemistry Photochemistry Biochemistry Catalysis law.invention Thymine chemistry.chemical_compound Colloid and Surface Chemistry Intersystem crossing chemistry Radical ion law Singlet state Electron paramagnetic resonance Cytosine |
| Zdroj: | Journal of the American Chemical Society. 135:10970-10973 |
| ISSN: | 1520-5126 0002-7863 |
| DOI: | 10.1021/ja4055405 |
| Popis: | 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. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|