One-dimensional iodine-rich iodobismuthates(III), Cat3{[Bi2I9](I2)3} [Cat = 1,4-MePy (1) and 1-EtBMAP (2)], feature the highest amount of "trapped"diiodine units in polyhalogen-halometalates of p-block elements. Both complexes have narrow optical band gaps (1.55 and 1.63 eV, respectively) and moderate thermal stability.