Dramatic Red-Shifted Fluorescence of [2.2]Paracyclophanes with Peripheral Substituents Attached to the Saturated Bridges

A bridge-substituted [2.2]paracyclophane obtained from the organic solid state exhibits a dramatic red shift in fluorescence relative to [2.2]paracyclophane. A further red shift occurs upon alkylation of the pyridylcyclobutyl bridges. Our results demonstrate that [2.2]cyclophanes substituted at the bridge, despite not being attached via the extended pi-system, are promising building blocks in the development of optical materials.