Intercalation of cationic phthalocyanines into layered titanates and control of the microstructures

Two cationic phthalocyanines (Pc), a tetravalent Alcian Blue pyridine variant (ABpy(4+)) and a monovalent iron(III) phthalocyanine (FePc+), were intercalated into two layered titanates derived from Na2Ti3O7 and Cs(x)Ti(2-x/4)square(x/4)O(4) (square = vacancy, x = 0.7) by using the corresponding propylammonium titanates as the intermediates for guest displacement reactions. When Na2Ti3O7 was used as a host, segregation occurred in the products, since it has a relatively higher layer charge density; some interlayer spaces accommodated Pc, but the others contained propylammonium cations. On the other hand, Pc cations were homogeneously intercalated into the interlayer spaces of Ti(2-x/4)square(x/4)O(4) layers. ABpy(4+) formed agglomerates in the gallery between Ti(2-x/4)square(x/4)O(4) layers, whereas FePc+ was distributed molecularly. In the ABpy-Ti(2-x/4)square(x/4)O(4) system, further ABpy(4+) was added or any remaining propylammonium cations were removed by thermal treatment under reduced pressure in order to vary the microstructure, which resulted in the formation of higher aggregated states of ABpy(4+). Electron transfer from FePc+ to Ti(2-x/4)square(x/4)O(4) induced by visible light irradiation was observed for FePc-Ti(2-x/4)square(x/4)O(4) by fluorescence measurements.