Synthesis and physico-chemical properties of cationic derivatives of phthalocyaninatocopper(II)

Abstract

4,11,18,25-Tetra(chlorosulphonyl)phthalocyaninatocopper(II) and its 3,10,17,24-isomer have been used to prepare organo-soluble 4,11,18,25-tetra(2-pyridylmethylaminosulphonyl)phthalocyaninatocopper(II) and its 3,10,17,24-isomer. These compounds in turn have been used to prepare water-soluble 4,11,18,25-tetra(N-methyl-2-pyridiniomethylaminosulphonyl)phthalocyaninatocopper(II) tetra(methyl sulphate) and its 3,10,17,24-isomer. Spectrophotometric and e.s.r. measurements show that the organo-soluble forms and the water-soluble derivatives give rise to solute–solute interactions in their appropriate solutions. The relative amounts of each species in the monomer–dimer–polymer equilibria depends on the composition of the appropriate solutions. E.s.r. measurements on frozen solutions of each of the phthalocyaninatocopper(II) derivatives show clear evidence for the formation of dimeric forms of the chelates which are characterized by spectra arising from magnetic dipole–dipole coupling between the copper(II) centres, which form a triplet state. The e.s.r. spectral component attributed to the dimeric species is closely similar for all the compounds studied so that dimer formation is entirely determined by interactions between the phthalocyanine ring system. Computer simulation of the experimental e.s.r. spectra due to the dimeric species makes possible the determination of the spin-Hamiltonian parameters associated with the copper(II) centres as well as the distance between the copper(II) centres. Some comparisons of the measurements have been made with commercially available phthalocyaninatocopper(II) dyestuffs in their organo-soluble and cationic water-soluble forms.