Preparation of polyetherol-appended sulfur porphyrazines and investigations of peripheral metal ion binding in polar solvents

We describe the complete synthesis and characterization of a new family of peripherally functionalized porphyrazines (pz's) with four, three, or two (in a trans conformation) bis[thioethoxy(ethoxy)ethanol] moieties appended at the pyrroles. These "polyetherol" groups serve as weak exocyclic binding sites for a number of metal ions and also provide solubility of the pz's in low molecular-weight alcohols and water. Electronic spectra of the modified porphyrazines exhibit distinct changes in the visible region (both absorbance and fluorescence) in response to treatment with Ag+, Pb2+, Cd2+, Cs+, and Ni2+ in solution. Such properties make these compounds intriguing candidates for incorporation into the transducer layers in optically based chemical sensors.