Expanded Rosarin: A Versatile Fullerene (C) Receptor.

An expanded rosarian (PP) with a bowl-like conformation has been prepared and characterized in a one-pot procedure that involves condensing a bispyrrole pyridine precursor (PP) with benzaldehyde, followed by oxidation. Single crystal X-ray diffraction analysis reveals a bowl-like conformation in the solid state with an upper rim diameter defined by the meso-phenyl substituents of ca. 13.5 Å and a depth of roughly 6.3 Å. PP forms both 1:1 and 2:1 complexes with C in the solid state. DFT reveals similar energies for the two binding modes. A 1:1 binding stoichiometry dominates in 1,2-dichlorobenzene-d at the millimolar concentrations dictated by solubility consideration. The solution phase interactions between rosarian and C were studied using H NMR, UV-vis, and femtosecond transient absorption spectroscopies in 1,2-dichlorobenzene-d or toluene. To our knowledge, this is the first report of an unfunctionalized porphyrinoid that forms a well-defined complex with C in solution as well as in solid state.