One- and Two-Dimensional Iodine-Rich Iodobismuthate(III) Complexes: Structure, Optical Properties, and Features of Halogen Bonding in the Solid State.

Reactions of BiI3, I2, and iodide salts of two different pyridinum cations result in the formation of the novel iodine-rich iodobismuthates(III) (1,3-MePy)4{[Bi4I16](I2)} (1) and (1-MePy){[BiI4](I2)0.5) (2), where the halometalate anions are connected by diiodine linkers into one- or two-dimensional supramolecular structures. Both complexes reveal narrow optical band gaps and fairly high thermal stability, favoring their potential use in photovoltaic devices.