Interfacial aggregation of thioether-substituted phthalocyaninatomagnesium(II)-palladium(II) complexes in the toluene/water system

摘要

The interfacial aggregation of three thioether-substituted phthalocyanine-magnesium(II) complexes,MgPc(SR)_8,of (2,3,9,10,16,17,23,24-octakis-ethylthiophthalocyaninato)magnesium(II),[MgPc(SEt)_8],(2,3,9,10,16,17,23,24-octakis-benzylthiophthalocyaninato)magnesium(II),[MgPc(SBz)_8],and (2,3,9,10,16,17,23,24-octakis-benzhydrylthiophthalocyaninato)magnesium(II),[MgPc(SBh)_8] were investigated in the toluene/water system by means of a centrifugal liquid membrane (CLM) method.Aggregation of MgPc(SR)_8 molecules at the interface was significantly promoted by the complexation with soft metal ions such as Pd(II) and Hg(II) added to the aqueous phase.The interfacial adsorption of MgPc(SEt)_8 was caused even in the absence of Pd(II) by the formation of a co-facial H-dimer,but the presence of Pd(II) promoted H-dimer aggregation at the interface.In the cases of MgPc(SBz)_8 and MgPc(SBh)_8,there was observed no significant self-aggregation,but in the presence of Pd(II),the interfacial aggregation of Pd(II) complexes of MgPc(SBz)_8 and MgPc(SBh)_8 proceeded remarkably.It was suggested that MgPc(SBz)_8-Pd(II) and MgPc(SBh)_8-Pd(II) could not form H-aggregates,because of the steric hindrance of benzyl or bezhydryl group,but they formed J-aggregates.Furthermore,MALDI-TOF/MS spectra indicated that oligomers of MgPc(SBz)_8-Pd(II) complex were formed at the liquid/liquid interface.The present study demonstrated the first example of Pd(II)-induced interfacial aggregation of phthalocyanine derivatives at the liquid/liquid interface,and suggested the possibility of controlling the aggregate structure between H- and J-aggregates by the size of peripheral substitute groups.