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

A bridge-substituted [2.2]paracyclophane (I) obtained from the org. 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 (II; R = Me, Et). Our results demonstrate that [2.2]cyclophanes substituted at the bridge, despite not being attached via the extended π-system, are promising building blocks in the development of optical materials. [on SciFinder(R)]