Anhydrous Photochemical Uranyl(VI) Reduction: Unprecedented Retention of Equatorial Coordination Accompanying Reversible Axial Oxo/Alkoxide Exchange

In a dramatic reversal of the normal trend of observed reactivity in uranyl(VI) coordination chemistry, an unprecedented retention of the normally labile equatorial coordination plane accompanies facile and reversible axial oxo/alkoxide exchange during both the photochemical reduction of cationic uranyl(VI) phosphine−oxide complexes with organic substrates and subsequent hydrolysis of the uranium(IV) alkoxide complexes to regenerate the uranyl(VI) starting complex.