Formation and geometrical control of polygon-like metal-coordination assemblies

Polygon-like [2+2]- and [3+3]-type metal complexes were prepared from dipyrrin dimers connected by acute-angled spacers. The electrical conduction depends strongly on the packing alignment of the compounds, revealing the presence of effective hopping pathways for holes with relatively high mobility up to 0.11 cm² V^-1 s^-1 along the aligned axis of [3+3]-type metal-bridged assemblies. These observations correlated with the geometrical control of the π-conjugated metal complexes in the cyclic structures, which enables their ordered arrangement in the assemblies. An electric association: Polygon-like [2+2]- and [3+3]-type metal complexes were prepared from dipyrrin dimers connected by acute-angled spacers. Stable geometries of the metal-bridged macrocycles were controlled by the substituents at pyrrole's α-positions. Furthermore, solid-state samples of the macrocycles showed electrical conductive properties based on the highly ordered assembled structures of π-electronic systems (see figure).