Fields Connor, Foerster Aleksandra, Ghaderzadeh Sadegh, Popov Ilya, Huynh Bang, Junqueira Filipe, James Tyler, Alonso Perez Sofia, Duncan David A, Lee Tien-Lin, Wang Yitao, Bloodworth Sally, Hoffman Gabriela, Walkey Mark, Whitby Richard J, Levitt Malcolm H, Kiraly Brian, O'Shea James N, Besley Elena, Moriarty Philip
School of Physics & Astronomy, University of Nottingham, Nottingham, UK.
School of Chemistry, University of Nottingham, Nottingham, UK.
Nat Commun. 2025 May 31;16(1):5062. doi: 10.1038/s41467-025-60260-z.
Charge transfer is fundamentally dependent on the overlap of the orbitals comprising the transport pathway. This has key implications for molecular, nanoscale, and quantum technologies, for which delocalization (and decoherence) rates are essential figures of merit. Here, we apply the core hole clock technique-an energy-domain variant of ultrafast spectroscopy-to probe the delocalization of a photoexcited electron inside a closed molecular cage, namely the Ar 2p4s state of Ar@C. Despite marginal frontier orbital mixing in the ground configuration, almost 80% of the excited state density is found outside the buckyball due to the formation of a markedly diffuse hybrid orbital. Far from isolating the intracage excitation, the surrounding fullerene is instead a remarkably efficient conduit for electron transfer: we measure characteristic delocalization times of 6.6 ± 0.3 fs and ≲ 500 attoseconds, respectively, for a 3D Ar@C film and a 2D monolayer on Ag(111).
电荷转移从根本上取决于构成传输路径的轨道的重叠。这对分子、纳米级和量子技术具有关键意义，对于这些技术而言，离域（和退相干）速率是至关重要的品质因数。在此，我们应用核心空穴时钟技术——超快光谱学的一种能量域变体——来探测封闭分子笼内光激发电子的离域，即Ar@C的Ar 2p4s态。尽管基态构型中的前沿轨道混合很微弱，但由于形成了明显弥散的杂化轨道，几乎80%的激发态密度出现在巴基球之外。富勒烯非但没有隔离笼内激发，反而成为了电子转移的极其有效的通道：对于Ag(111)上的三维Ar@C薄膜和二维单层，我们分别测量到特征离域时间为6.6±0.3飞秒和≲500阿秒。
