Vibrational studies of iron phthalocyanines in zeolites

The range of zeolites which are suitable as host for phthalocyanines is limited, because of the size of these ligands. Generally, faujasite structures are preferred. Synthesis of phthalocyanines in the internal space of zeolites is exceptional in that mostly, the ligand is itself synthesized in situ before complexation of the metal ion. Moreover, depending on the metal source (salts, carbonyl complexes or metallocenes) distinct synthesis procedures can be recognized. FT-IR and Raman data are presented for the structure of phthalocyanines encapsulated in faujasite type zeolites. A new conformational model for the encapsulation of metal-phthalocyanines in the supercage of zeolite Y resolves the apparent contradiction between molecular modelling and spectroscopy of these catalysts. In the present model, two aromatic rings of the phthalocyanine are pushing against the supercage walls.