The aggregation of the tetrasodium salt of copper phthalocyanine 4,4',4',4''-tetrasulphonic acid

Abstract

The aggregation of the tetrasodium salt of copper phthalocyanine-4,4',4",4??? tetrasulphonic acid has been investigated by equilibrium spectrophotometric measurements at 25�. At low concentrations this can be treated in terms of a monomer-dimer equilibrium. Owing to the strong aggregating tendency of this molecule in water, it was necessary to evaluate the dissociation constant together with the monomer and dimer spectra from measurements made in 20% ethanol solutions. By means of these data, the corresponding dissociation constant in water has been determined.

Dimerisation of mononuclear and binuclear cobalt phthalocyanines

“…This is consistent with the 3-4 order of magnitude difference between K D of CuPcX4 in benzene (13,14) and CuTsPc in water (3,4,6). In contrast, the KD values of Zn and VO phthalocyanines are approximately of the same order for MPcX4 in benzene (13,14) and MTsPc in water (3)(4)(5).…”

“…l), while the absorbance at 612 nm increased further relative to 678 nm. This shows a greater tendency for aggregation as the ionic strength of the solution is increased, which was also noted for phthalocyanines in aqueous solution (3,(5)(6)(7)(8)(9)(10). Figure 2a CoTNPc-TBAP interactions occur.…”

“…The spectra measured at <5 x lop6 M were taken as those of the pure monomeric forms. Absorption The spectroscopic data can be used to derive the electronic spectra for the pure aggregate dimeric species following the method of West and Pearce (6,7,20). These spectra are shown in Figs.…”

“…Extensive studies on the water-soluble tetrasulphonated phthalocyanines (TsPc) (1)(2)(3)(4)(5)(6)(7)(8)(9)(10) have shown a tendency for these complexes to dimerise in aqueous solution, the extent of dimerisation depending strongly upon the nature of the central substituent in the phthalocyanine ring. Typically, the dimer has a Q band absorption at ca.…”

Influence of Surfactant-based Microheterogeneous Fluids on Aggregation of Copper Phthalocyanine Tetrasulfonate

“…Aggregation equilibria were investigated by visible spectroscopy in 1-100 mM solutions of Cu As reported previously [29][30][31][32][33][34][35][36][37][38], a monomer peak in the 660-680 nm region and an aggregate band near 630 nm were found (Fig. 1).…”