Latawiec Elisabeth I, Chiesa Alessandro, Qiu Yunfan, Tcyrulnikov Nikolai A, Young Ryan M, Carretta Stefano, Krzyaniak Matthew D, Wasielewski Michael R
Department of Chemistry, Institute for Quantum Information Research and Engineering, and Center for Molecular Quantum Transduction, Northwestern University, Evanston, IL 60208-3113.
Dipartimento di Scienze Matematiche, Fisiche e Informatiche, Università di Parma, Parma I-43124, Italy.
Proc Natl Acad Sci U S A. 2025 Aug 12;122(32):e2515120122. doi: 10.1073/pnas.2515120122. Epub 2025 Aug 5.
Chirality-induced spin selectivity (CISS) results in spin polarization of electrons transmitted through chiral molecules and materials. Since CISS results in spin polarization even at room temperature, it affords the possibility of using it to develop quantum technologies that can operate under ambient conditions. We have shown previously that photo-driven hole transfer within DNA hairpins provides a facile route to generate spin-correlated radical pairs (SCRPs). To study the effect of CISS on the spin dynamics of SCRPs in DNA hairpins, we prepared a series of electron donor-chiral bridge-acceptor molecules where the chiral bridge is a B-form DNA helix consisting of 4 to 6 base pairs. Naphthalene-1,8:4,5-bis(dicarboximide) (NDI) serves as the hairpin linker chromophore and electron acceptor. Photoexcitation of NDI results in rapid hole transfer through the π-stacked purine bases of the DNA and trapping of the hole on a terminal stilbene diether (Sd) to generate the NDI- Sd SCRP. Time-resolved electron paramagnetic resonance spectra of the SCRPs at X- (9.6 GHz), Q- (34 GHz), and W- (94 GHz) bands show that the CISS effect imparts significant triplet character to the SCRP. We do not observe a significant dependence of CISS on DNA length, likely resulting from hole delocalization over the guanine bases in the G-tract. Interestingly, we find that the CISS contribution significantly increases with magnetic field strength. These findings should be considered in any future modeling of CISS.
手性诱导自旋选择性（CISS）导致电子通过手性分子和材料传输时产生自旋极化。由于CISS即使在室温下也会导致自旋极化，因此它为利用其开发可在环境条件下运行的量子技术提供了可能性。我们之前已经表明，DNA发夹内的光驱动空穴转移提供了一种生成自旋相关自由基对（SCRP）的简便途径。为了研究CISS对DNA发夹中SCRP自旋动力学的影响，我们制备了一系列电子供体-手性桥-受体分子，其中手性桥是由4至6个碱基对组成的B型DNA螺旋。萘-1,8:4,5-双（二甲酰亚胺）（NDI）用作发夹连接发色团和电子受体。NDI的光激发导致空穴通过DNA的π堆积嘌呤碱基快速转移，并将空穴捕获在末端二苯乙烯二醚（Sd）上，以生成NDI-Sd SCRP。在X波段（9.6 GHz）、Q波段（34 GHz）和W波段（94 GHz）对SCRP进行时间分辨电子顺磁共振光谱表明，CISS效应赋予SCRP显著的三重态特征。我们没有观察到CISS对DNA长度有显著依赖性，这可能是由于空穴在G链中的鸟嘌呤碱基上离域所致。有趣的是，我们发现CISS的贡献随着磁场强度的增加而显著增加。在未来任何关于CISS的建模中都应考虑这些发现。
