Syntheses, structures, and electrochemistry of a dialkoxo-bridged diuranyl(VI) compound [(UO 2 ) 2 (L 1 ) 2 (dimethylformamide) 2 ] (1) and a mononuclear-mononuclear cocrystalline compound 2) derived from Schiff base ligands are reported (H 2 L 1 = Schiff base ligand obtained on condensation of 3-ethoxysalicylaldehyde with 2-aminoethanol; H 2 L 2 = N,N′-ophenylenebis(3-ethoxysalicylaldimine)). The compounds 1 and 2 crystallize in the space groups P2 1 /c and P1, respectively. Compound 1 is a dialkoxo-bridged dinuclear compound of uranium(VI) containing two deprotonated ligands, [L] 2-, two dimethylformamide (dmf) molecules and two UO 2 2+ centers. Three C-H⋅⋅⋅O type hydrogen bonds involving one uranyl oxygen, two dmf hydrogens, and the imine hydrogen link the dinuclear units into a two-dimensional network. Compound 2 is a cocrystal of two mononuclear units,
In unit 1, the non-coordinated water molecule forms hydrogen bonds with oxygens of phenoxo, ethoxy, and coordinated water molecules resulting in the formation of an inclusion product. The overall supramolecular structure of compound 2 is onedimensional and consists of interlinked self-assembled dimeric unit of unit 1 and unit 2. Cyclic voltammetric measurements reveal that the uranium(VI) center in [(UO 2 ) 2 (L 1 ) 2 (dimethylformamide) 2 ] (1) is reduced quasireversibly at E ½ = -773 mV with ΔE P = 121 mV, while the metal center in 2) is reduced reversibly with E ½ = -765 mV with ΔE P = 68 mV. Dedicated to Prof. Ladislav Bohatý on the occasion of his 60 th birthday