1,8-Pyrenylene-Ethynylene Macrocycles

A concise, highly regioselective synthesis of 1,8-dibromo-4,5-dialkoxypyrenes has been developed and exploited in the synthesis of some 1,8-pyrenylene−ethynylene macrocycles. The 1H NMR data and NICS calculations indicate that there is little or no macrocyclic ring current. Concentration-dependent UV−visible studies indicate no aggregation at low concentration, but 8b forms dimers with voids suitable for intercalation of small molecules in the solid state.