Synthesis of metal-free and zinc phthalocyanines containing 2-pyridyl-methyl pendant arm linked with NS4-donor macrocyclic moiety and their selectivity towards Cu(II) cations

Abstract

New phthalonitrile (L1), metal-free phthalocyanine (H2Pc) and zinc-phthalocyanine (ZnPc) substituted in peripheral positions with 2-pyridyl methyl pendant arm linked mixed donor macrocyclic ligands have been prepared in a multi-step reaction sequence. The novel compounds were characterized by a combination of elemental anlaysis, 1 H NMR, 13 C NMR, IR, UV-vis and MS spectral data. The influence of metal cations such as Cd 2+, Zn 2+, Hg 2+, Al 3+, Fe 3+ and Cu 2+ on the spectroscopic properties of dinitrile compound L1 and free phthalocyanine H2Pc was investigated by means of absorption spectrophotometry. Spectrophotometric titrations were carried out with these ligands for Cu 2+ ion. The complex composition of Cu - L1 was found 1:1 by means of spectrophotometric titration data. The spectrophotometric method showed good sensitivity for Cu 2+ with linear range of 2.6 × 10-6 to 1.3 × 10-4 M with dinitrile compound.