An Anomalous Electron Configuration Among 3d Transition Metal Atoms

• Published in: Angewandte Chemie 2023-02, Vol.135 (7), p.n/a
• Main Authors: Tang, Zhexin, Shang, Tongtong, Xu, Han, Lin, Ting, Gao, Ang, Lin, Weiguang, Li, Xinyan, Wang, Shiyu, Yu, Botao, Meng, Fanqi, Zhang, Qinghua, Wang, Xuefeng, Su, Dong, Meng, Qingbo, Wu, Lijun, Gu, Lin, Nan, Ce‐Wen
• Format: Article
• Language: English
• Subjects: Chemistry; Configurations; Divergence; Electron Configuration; Electron density; Electron Density Distribution; Electron diffraction; Electron Microscopy; Electron orbitals; Inorganic materials; Material properties; Metal compounds; Physical properties; Population density; Quantitative Convergent-Beam Electron Diffraction; Scandium; Transition metal compounds
• ISSN: 0044-8249; 1521-3757
• DOI: 10.1002/ange.202216898

Physical properties of materials are mainly determined by valence electron configurations, where different valence shells would induce divergent phenomena. In compounds containing Sc2+, 3d electron occupancy is expected, the same as other transition metal atoms like Ti3+. But this situation still awaits experimental verification in inorganic materials. Here, we selected ScS to measure the valence electron density and orbital population of Sc2+ through delicate quantitative convergent‐beam electron diffraction. With the absence of 3d orbital features around Sc‐atom sites and the nearly bare population of t2g orbital, the unintuitive occupation of 4s orbital in Sc2+ is concluded. It should be the first time to report such a special electron configuration in a transition metal compound, in which 4s rather than 3d orbital is preferred. Our findings reveal the distinct behavior of Sc and probable ways to modulate material properties by controlling electron orbitals. A special [Ar]4s1 electron configuration was revealed for Sc2+ in ScS, with no typical 3d orbital features and a bare population of t2g orbital from electron density reconstruction and orbital population analysis. Our work should be the first to report such anomalous electron structure with preferred 4s over 3d orbital for 3d transition metal atoms and may provide a new method to modulate material properties via artificial orbital adjustment.