RAMAN MICROSPECTROSCOPY OF PHTHALOCYANINE INTERCALATES - TETRASULFONATED COBALT AND NICKEL PHTHALOCYANINES IN LAYERED DOUBLE HYDROXIDE

Tetrasulfonated cobalt and nickel phthalocyanines (CoPcTs and NiPcTs, respectively) intercalated in layered double hydroxide (LDH) were stud ied by Raman microscopy, In the case of the cobalt complex the investi gation included the supported sample in which the phthalocyanine is no t within the LDH galleries but on its outer surfaces, The interaction of CoPcTs with the surface (in both intercalated and supported samples ) caused band shifting and changes in the relative intensities of some bands, The results for the intercalated compound are in agreement wit h x-ray data, showing that the phthalocyanine assumes an edge-on orien tation in the LDH galleries electrostatically bound through the sulfon ate groups, with negligible participation of the pi-electrons, This is not the case for supported CoPcTs, since the shift and changes in the relative intensity of the 1546 cm(-1) peak are consistent with variat ions in the pyrrole ring charge, as expected for a hat orientation wit h respect to the surface, The spectral behavior of NiPcTs does not fol low that of CoPcTs, The Raman spectrum suggests that the nickel comple x intercalates as an aggregate, which is confirmed by diffuse reflecta nce data and x-ray diffraction. (C) 1998 John Wiley & Sons, Ltd.