Anthracene-Containing Podands, Ion-Active Molecular Switches of Fluorescence Characteristics

2,2′-[Ethane-1,2-diylbis(oxy)]bis[ N -(anthracen-9-ylmethyl)ethanamine] and its bisphenylthiourea and bisthiourea derivatives have been synthesized. The diamine, being a certain analog of an aza-crown ether with an open chain, exhibits a 50 times increase in the relative fluorescence intensity ( off-on process) in the presence of cadmium(II) cations. Bis(phenylthiourea) is a bifunctional fluorophore sensitive to mercury(II) cations (emission flaring) and fluoride anions (emission quenching). Anions F – , CN – , H 2 PO 4 – , and AcO – lead to a practically complete quenching of the fluorescent properties of the bis(thiourea) ( off-on process).