Copper(I) and Copper(II) Uranyl Heterometallic Hybrid Materials

Two copper–uranium heterometallic compounds, [(UO2)3CuIIO2(C6NO2)5] (1) and [(UO2)­CuI(C6NO2)3] (2), have been synthesized by the reaction of uranyl acetate with copper salts in the presence of isonicotinic acid. Both compounds have been characterized by single-crystal X-ray diffraction, IR, Raman, and UV–vis spectroscopy. In compound 1, interactions between copper and uranium centers occur and result in a three-dimensional pillar layered structure. Compound 1 is also the first example of a heterometallic uranyl organic framework with a trinuclear U3O18 building block. Compound 2 is the first uranyl organic framework that contains monovalent copper, which arises from the reaction of Cu­(II) chloride and is assumed to be due to the oxidation of chloride at low pH.