Exceptionally Long Lifetimes of Strongly Entangled Acyl–Trityl Radical Pairs Photochemically Generated in Crystalline Trityl Ketones
Exceptionally Long Lifetimes of Strongly Entangled Acyl–Trityl Radical Pairs Photochemically Generated in Crystalline Trityl Ketones
复制标题
结晶三苯甲基酮中光化学产生的强缠结酰基-三苯甲基自由基对的寿命极长
DOI：
10.1021/jacs.2c11787
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发表时间：
2023
影响因子：
15
通讯作者：
Garcia-Garibay, Miguel A.
中科院分区：
文献类型：
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作者：
Hipwell, Vince M.;Meyer, Alana Rose;Garcia-Garibay, Miguel A.
三重态酰基-烷基自由基对通过脉冲激光激发在其纳米晶体酮前体的约束下产生，最近被引入作为用于在量子信息科学中应用的自旋量子比特对的稳健和重复实例化的潜在平台。在这里，我们报告了一系列的纳米晶三苯甲基-烷基和三苯甲基-芳基酮的瞬态光谱能够产生相关的三重态自由基对持久的三苯基甲基自由基被迫保持在键合距离内的高反应性酰基自由基。而三重态三苯甲基-酰基自由基对通过竞争产物形成脱羰基和系间交叉而衰减，三重态三苯甲基-苯甲酰基自由基对的寿命高达约。4 ms，并且仅再生起始酮。我们提出，这些长的寿命是短的根间距离和两个单占据轨道的共线取向的结果，这预计会导致大的单重态-三重态能隙，大的零场分裂参数，以及自旋轨道耦合的几何形状差。生成三苯甲基-苯甲酰基自由基对的酮在沿着多个维度上表现出有前途的性能，这对量子信息科学至关重要。
Triplet acyl–alkyl radical pairs generated by pulsed laser excitation within the constraints of their nanocrystalline ketone precursors were recently introduced as a potential platform for the robust and repeated instantiation of spin qubit pairs for applications in quantum information science. Here, we report the transient spectroscopy of a series of nanocrystalline trityl–alkyl and trityl–aryl ketones capable of generating correlated triplet radical pairs with persistent triphenylmethyl radicals forced to remain within bonding distances of highly reactive acyl radicals. Whereas triplet trityl–acyl radical pairs decay by competing product-forming decarbonylation and intersystem crossing, triplet trityl–benzoyl radical pairs have lifetimes of up to ca. 4 ms and exclusively regenerate the starting ketone. We propose that these long lifetimes are the result of the short inter-radical distances and the colinear orientation of the two singly occupied orbitals, which are expected to result in large singlet–triplet energy gaps, large zero-field splitting parameters, and a poor geometry for spin-obit coupling. Ketones generating trityl–benzoyl radical pairs demonstrate promising performance along multiple dimensions that are crucial for quantum information science.