Nanoscale Hollow Spheres of an Amphiphilic Mixed (Phthalocyaninato)(porphyrinato)europium Double-Decker Complex

A novel amphiphilic sandwich-type mixed (phthalocyaninato)(porphyrinato)europium double-decker complex Eu(Pc)-[T(OH)(3)PP] [Pc = phthalocyaninate, T(OH)(3)PP = 5,10,15-tris(4-hydroxyphenyl)-20-(4-tert-butylphenyl)porphyrinate] (1) was designed, prepared, and characterized by a range of spectroscopic methods in addition to elemental analysis. By employing a solution injection method, this compound self-assembles into nanoscale hollow spheres with an average diameter of ca. 70 nm. The hollow spherical structure was determined by transmission electronic microscopy and scanning electronic microscopy. Comparison in the electronic absorption spectrum between the aggregate and the compound itself in solution reveals the J-aggregation packing mode of the amphiphilic double-decker molecules in nanoscale hollow spheres. The present work represents the first example of nanoscale hollow sphere morphology self-assembled from sandwich tetrapyrrole rare-earth complexes.