Facile synthesis of heterogeneous macrocycles for intramolecular energy transfer.

Heterogeneous macrocycles with fluorenone and fluorenol functional groups are synthesized by two facile methods involving post-modification on the macrocycles and one-pot co-cyclization from different monomers. Significantly, benefitting from the well-matched absorption/emission spectra and close distance of fluorenone/fluorenol moieties, the obtained heterogeneous macrocycles exhibit intriguing intramolecular energy transfer (ET) and fluorescence enhancement.