Intrinsic Semiconducting Behavior in a Large Mixed‐Valent Uranium(V/VI) Cluster

Abstract

We disclose the intrinsic semiconducting properties of one of the largest mixed-valent uranium clusters, [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 Xray excitation for 1: a large on-off ratio of 500 and considerable charge mobility lifetime product of 2.3 10 À4 cm 2 V À1 , as well as a high detection sensitivity of 23.4 mC Gy air À1 cm À2 .

Photoelectrochemical uranium extraction from uranium mine tailings seepage water

“…And a facile U(V) synthesis method is useful for assisting future studies on the U(V) chemistry. Additionally, because of its unique electronic structure 42 , stable U(V) materials is also highly desired for photocatalysis, magnetism, and energy storage applications 42,43 . However, due to fast disproportionation 6 , U(V) species are usually very unstable 9,13,19,44 .…”

“…However, due to fast disproportionation 6 , U(V) species are usually very unstable 9,13,19,44 . Attempts have been made by pioneers in synthesizing stable U(V), but the state-of-the-art methods are complicated and time-consuming, requiring the addition of organic ligands, heating, high pressure, and/or high voltage 33,34,[41][42][43]45,46 . To our best knowledge, this study is the first in successfully producing stable U(V) from aqueous media without adding organic ligands, under ambient conditions and in open air.…”

Double-Layer Nitrogen-Rich Two-Dimensional Anionic Uranyl–Organic Framework for Cation Dye Capture and Catalytic Fixation of Carbon Dioxide

“…Coordination polymers (CPs) are new crystalline materials made by self-assembly of metal ions/clusters as nodes with inorganic/organic ligands. − CPs have attracted widespread attention in terms of adsorption separation, catalysis, − energy storage, sensors, , electrical conductivity, , and other fields, − due to advantages such as a low density, a large specific surface area, a high porosity, an adjustable pore size, and diverse topological structures. Metal–organic frameworks (MOFs) with transition or lanthanide metal nodes have occupied the mainstream of related research fields for decades. − Although there have been relatively few studies of actinide MOFs, they are of great significance; they not only provide basic knowledge of actinides closely related to the nuclear fuel cycle but also are helpful for the development of actinide materials with novel topologies and unique features. , As representatives of actinide MOFs, uranyl–organic frameworks (UOFs) have attracted a great deal of attention because of their low radioactivity and varied coordination geometries. − …”

Intrinsic Semiconducting Behavior in a Large Mixed‐Valent Uranium(V/VI) Cluster

“…a) Molecular structure of 1. [19] b) The polyhedral view of 1. normalized XANES spectra for 1 and UO 2 (NO 3 ) 2 •6 H 2 O. The absorption features correspond to electric-dipole-allowed transitions from U 2p 3/2 core level to unoccupied 6d/7s level, in which the energy of infection point in absorption edge is generally correlated with oxidation state of absorbing atoms.…”