The effect of protonation on the spectra and stabilities of alkoxyl substituted phthalocyaninatometals

The protonation abilities of phthalocyaninatometals (MPcs) increase but their stabilities reduce by the introduction of alkoxyl substituents at α position. In the toluene, the order of mono-protonation rate for the tetra-α-(2, 2, 4-trimethyl-3-pentoxy)phthalocyaninatometals sorts with the center metals is Zn > Co > Cu > Ni > Fe, which is opposite to the order of their wavelength difference between the Q bands and X bands. However, their mono-protonated species can be decomposed easily at the rate order FePc > CoPc > CuPc > NiPc > ZnPc, analogous to their decomposition abilities in the benzoylperoxide (BPO) oxidation. In addition, it is interesting that a more remarkable decomposition is found when partial CuPc was mono-protonated.