Foxley Juniper, Tofanelli Marcus, Knappenberger Jane A, Ackerson Christopher J, Knappenberger Kenneth L
Department of Chemistry, Pennsylvania State University, University Park, Pennsylvania 16802, United States.
Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States.
ACS Cent Sci. 2025 May 29;11(8):1329-1335. doi: 10.1021/acscentsci.5c00139. eCollection 2025 Aug 27.
Au(SCH), a colloidal cluster with a 1.7 nm inorganic diameter, exhibits both metallic and molecular-like behavior, along with a distribution of unfilled superatom states. Its 1.7-2.5 eV electronic transitions were probed with variable-temperature, variable-field magnetic circular dichroism (VTV -MCD), revealing two energy regions with distinct responses. Below 2.0 eV, MCD transitions exhibited diverse VTV responses, including both paramagnetic and diamagnetic behavior, implicating multiple nondegenerate initial states originating within the open-shell superatom S, D, and H HOMO manifold. Above 2.0 eV, uniform field-dependent responses suggested spin-vibronic coupling due to metal-ligand mixing. The Au(SCH) magneto-optical response is surprisingly complex given the system's high electronic-state density; discrete structural domains of the cluster, including the superatomic metal core, likely contribute to this diversity. These results show the potential to investigate and tailor the magneto-optical and spin properties of these clusters through structurally precise synthesis and also identify superatomic colloids as candidates for advancing spin-based technologies.
直径为1.7纳米无机尺寸的胶体团簇Au(SCH)，兼具金属和类分子行为，同时存在未填充的超原子态分布。利用变温、变场磁圆二色性（VTV -MCD）对其1.7 - 2.5电子伏特的电子跃迁进行了探测，发现有两个能量区域呈现出不同的响应。在2.0电子伏特以下，MCD跃迁表现出多样的VTV响应，包括顺磁和抗磁行为，这意味着开壳层超原子S、D和H的最高占据分子轨道（HOMO）流形中存在多个非简并初始态。在2.0电子伏特以上，均匀的场依赖响应表明由于金属 - 配体混合导致了自旋 - 振动耦合。考虑到该系统的高电子态密度，Au(SCH)的磁光响应出人意料地复杂；团簇的离散结构域，包括超原子金属核，可能是造成这种多样性的原因。这些结果表明，通过结构精确合成来研究和调控这些团簇的磁光和自旋性质具有潜力，同时也确定了超原子胶体是推进基于自旋技术的候选材料。
