Photochemistry of uranium(VI) revisited: A density functional theory study

Photochemical reduction of uranium(VI) in the presence of organic substances is a well known and well studied process, but its reaction mechanism has not yet been fully verified. One of the difficulties in studying uranium photochemistry is the involvement of photo-excited states which is difficult to assess solely by experiments. Quantum chemical calculation is capable of predicting the properties of excited state uranium(VI), and therefore can provide possible photochemical reaction mechanisms and reaction pathways. Here, we have studied the photochemical reduction of uranium(VI) in the presence of several organic ligands, namely methanol, ethanol, and oxalic acid, by density functional theory (DFT) calculations. We were able to reproduce entire reaction pathways which demonstrates the validity of the DFT approach in further exploring uranium(VI) photochemistry.