Azathia crown ethers carrying pyrene pendant as receptor molecules for metal sensor systems

A series of crown ethers carrying a pyrene group with nitrogensulfur donor atoms, that differ in having three, four and five sulfur atoms in the macrocycle was designed and synthesized by the reaction of the corresponding macrocyclic compound and 1-bromomethylpyrene. The influence of metal cations such as Mn 2+, Fe2+, Fe3+, Co2+, Ni 2+, Cu2+, Zn2+, Cd2+, Hg 2+, Pb2+ and Al3+ on the spectroscopic properties of the ligands was investigated in acetonitriledichloromethane (1:1) by means of absorption and emission spectrometry. Absorption spectra show isosbestic points in the spectrophotometric titration of Fe2+, Zn2+, Cu2+, Pb2+ and Hg2+. The results of spectrophotometric titration experiments disclosed the complexation compositions and complex stability constants of the novel ligands with Fe 2+, Zn2+, Cu2+, Pb2+ and Hg 2+ cations. The monoazatetrathia crown ether showed good sensitivity for Cu2+ with linearity in the range 5.0×10-72. 5×10-6 M and detection limit of 1.6×10-8 M.