Modified calix[4]pyrroles

The synthesis and chemical properties of a variety of chemically modified c alix[4]pyrroles are described. The effects of structural changes, specifica lly the presence and absence of substituents on the meso-like and beta-pyrr olic carbons, on anion affinities are detailed as is their effect on macroc ycle conformation. Also described are unsymmetrical systems, bearing an ali phatic and aromatic substituent on each of the four meso-like carbon atoms. In this case, the properties of the resulting configuration isomers are di scussed in terms, again, of the resulting effects oil macrocycle conformati on and substrate binding affinity. Finally, the use of appropriately functi onalized calix[4]pyrrole systems as rudimentary fluorescence-based anion se nsors is presented.