Iodine-Rich Supramolecular Complexes of Chlorobismuthates(III): Unusual Lone Pair Activity and Features of Halogen Bonding in Crystals.

The first chrorobismuthate(III) supramolecular hybrids with halogen-bond-linked I 2 , (Py(CH 2 ) 2 Py){[BiCl 5 ](I 2 )} ( 1 ) and (Py(CH 2 ) 3 Py){[BiCl 5 ](I 2 ) 0.5 } ( 2 ), were synthesized via the reaction between Bi 2 O 3 , I 2 , and salts of the corresponding cations in HCl. The compounds featured one- and two-dimensional (2D) supramolecular motifs built by I···Cl contacts; in the case of 1 , Bi(III) is pentacoordinated due to the lone pair activity, which also interacted with I 2 pi-orbitals, as confirmed by density functional theory (DFT) calculations. Both complexes exhibited moderate thermal stabilities and relatively narrow optical band gaps.