TY - JOUR
T1 - Photoselective DNA hairpin spin switches
AU - Carmieli, Raanan
AU - Thazhathveetil, Arun K.
AU - Lewis, Frederick D.
AU - Wasielewski, Michael R.
PY - 2013/7/31
Y1 - 2013/7/31
N2 - 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.
AB - 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.
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U2 - 10.1021/ja4055405
DO - 10.1021/ja4055405
M3 - Article
C2 - 23855976
AN - SCOPUS:84881080218
SN - 0002-7863
VL - 135
SP - 10970
EP - 10973
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 30
ER -