Abstract: The influence of n-hexadecyltrimethylammoniumbromide (CTAB) on the reaction between cobalt tetrasulphonated phthalocyanine (CoTsPc) and sodium sulfide has been investigated. The result shows that in the presence of the micelles, cobalt tetrasulphonated phthalocyanine can be reduced by sodium sulfide at pH 8.5~9.5 to forms the corresponding Co(I) complex. The mechanism of the reaction is also discussed. Using the method of multi-wavelength and double-parameter, UV-Vis spectra of the system are analyzed and the thermodynamics of the reaction is reported. In the CTAB micelle(cCTAB=8.36×10^-3 mol•L^-1) and 303 K, the changes of standard free energy, enthalpy and entropy of the reaction(ΔGΘ, ΔHΘ and ΔSΘ) are －17.28 kJ•mol^-1, 84.1 kJ•mol^-1 and 335 J•mol^-1•K^-1 respectively.

Key words: CTAB, Tetrasulphated phthalcyanine, Cobalt coordination compound, Sulfide, Coordination reaction, Thermodynamics