The coordinatively unsaturated 16-electron half-sandwich precursors [Cp*M(pdt)] (M = Rh and Ir, pdt = pyrazine-2,3-dithiol) have been synthesized. Their bridging and unsaturated attributes are further used in stepwise assembly reactions with binuclear blocks to give a closed molecular box.
Based on three tetradentate ligands with conjugated centers, seven half-sandwich octanuclear complexes were selectively obtained. Several subsequent structural conversions were also successfully conducted.