Metal–organic hybrids involving the [UO2Cl3(NO3)]2− tecton and the role of halogen polarizability

Abstract

The reaction of uranyl nitrate hexahydrate with 4-halopyridinium ions (X = Cl, Br, I) in high chloride media has resulted in three novel compounds, each of which is based around the [UO₂Cl₃(NO₃)]²⁻ tecton; (C₅H₅NCl)₂[UO₂Cl₃(NO₃)], (C₅H₅NBr)₂[UO₂Cl₃(NO₃)] and (C₅H₅NI)₃[UO₂Cl₃(NO₃)](NO₃). In each material the halogen is involved in various forms of intermolecular interaction, including hydrogen bonding, halogen–halogen interactions and halogen–nitrate interactions. Presented is a discussion of the role of the halogen, in terms of Lewis acidity, in directing the overall structure.