Transannular Interaction in the Excited Triplet States of [2.2]Paracyclophane and Related Compounds

The triplet-triplet absorption spectra of [2.2]paracyclophane and related cyclophanes (naphthalenophane, pyrenophane, and anthracenophane) were measured. Cyclophanes in which two component subunits fully overlap, show new bands together with monomer-like bands. The electronic structures of triplet states of these cyclophanes were studied theoretically by the “molecules in molecule” method, special attention being paid to the correlations of the electronic structures of cyclophanes with those of corresponding monomers and also to the dependences of the charge transfer interaction upon the overlapping between the component subunits and upon the molecular size.