Utilizing hydrogen bonds and halogen–halogen interactions in the design of uranyl hybrid materials

Reactions of the uranyl cation (UO(2)(2+)) with 4-halopyridinium ions (X = Cl, Br, I) in high halide media (X' = Cl, Br) have produced six novel compounds, the structures of which have been determined by single crystal X-ray diffraction (XRD). The compounds can be divided into two categories based on the different modes of hydrogen bonding and halogen-halogen interactions present in the crystal structures, with one group showing approximately Type I halogen-halogen interactions and the second showing Type II. Presented is a discussion of the relative strengths of the interactions as a function of halogen size.