Photoluminescence of Pentavalent Uranyl Amide Complexes

Abstract

Pentavalent uranyl species are crucial intermediates in transformations that play a key role for the nuclear industry and have recently been demonstrated to persist in reducing biotic and abiotic aqueous environments. However, due to the inherent instability of pentavalent uranyl, little is known about its electronic structure. Herein, we report the synthesis and characterization of a series of monomeric and dimeric, pentavalent uranyl amide complexes. These synthetic efforts enable the acquisition of emission spectra of well-defined pentavalent uranyl complexes using photoluminescence techniques, which establish a unique signature to characterize its electronic structure and, potentially, its role in biological and engineered environments via emission spectroscopy.

Synthesis and Characterization of Isostructural Th(IV) and U(IV) Pyridine Dipyrrolide Complexes

“…The goal of isolating isostructural U­( Mes PDP Ph ) 2 and Th­( Mes PDP Ph ) 2 compounds was identified as a means to probe what consequences the addition of f electrons may have on the electronic properties of the resulting An­( Mes PDP Ph ) 2 complexes. In addition, with the exception of uranyl complexes whose photophysical properties have been studied in depth, ,− photophysical studies of molecular actinide compounds are rare.…”

Insights into the Electronic Structure of a U(IV) Amido and U(V) Imido Complex

“…[12] The main factors influencing the stability of a certain oxidation state and thus reactivity arise from differences of the actinides' electronic structure, which is strongly affected by for example organic ligands as complexation partners but also by the reaction conditions. In recent years, N donor ligands gained centre stage for stabilizing uranium over a wide range of oxidation states due to the quite flexible number of bonds they can form: They can thus be utilized as amide [12][13][14][15] or imine [16][17][18][19] functionalities, and even triple bonds as nitrides [12,[20][21][22][23] are possible. Interestingly, bonds from imino ligands to U(VI) are more covalent compared to their dioxo analogues and capable of inducing further electronic effects like the inverse trans influence (ITI), opening an opportunity to shed light on 5forbital involvement.…”