Intrinsic Semiconducting Behavior in a Large Mixed‐Valent Uranium(V/VI) Cluster
Mingxing Zhang, Chengyu Liang, Guo‐Dong Cheng, Junchang Chen, Yumin Wang, Yumin Wang, Linwei He, Liwei Cheng, Shicheng Gong, Duo Zhang, Jiong Li, Shu‐Xian Hu, Juan Diwu, Guozhong Wu, Yaxing Wang, Yaxing Wang, Zhifang Chai, Shuao Wang
Abstract
Abstract We disclose the intrinsic semiconducting properties of one of the largest mixed‐valent uranium clusters, [H 3 O + ][U V (U VI O 2 ) 8 (μ 3 ‐O) 6 (PhCOO) 2 (Py(CH 2 O) 2 ) 4 (DMF) 4 ] (Ph=phenyl, Py=pyridyl, DMF=N,N‐dimethylformamide) ( 1 ). Single‐crystal X‐ray crystallography demonstrates that U V center is stabilized within a tetraoxo core surrounded by eight uranyl(VI) pentagonal bipyramidal centers. The oxidation states of uranium are substantiated by spectroscopic data and magnetic susceptibility measurement. Electronic spectroscopy and theory corroborate that U V species serve as electron donors and thus facilitate 1 being a n‐type semiconductor. With the largest effective atomic number among all reported radiation‐detection semiconductor materials, charge transport properties and photoconductivity were investigated under X‐ray excitation for 1 : a large on‐off ratio of 500 and considerable charge mobility lifetime product of 2.3×10 −4 cm 2 V −1 , as well as a high detection sensitivity of 23.4 μC Gy air −1 cm −2 .