Clathrate Formation from Octaazaphthalocyanines PossessingBulky Phenoxyl Substituents: A New Cubic Crystal ContainingSolv ent-Filled, Nanoscale Voids

摘要

The synthesis of octaazaphthalocyanine (AzaPc) derivatives,with bulky phenoxyl substituents placed at eight peripheral positions and containing either H+,Ni 2+ or Zn2+ ions in their central cavity,is described. The required precursors,derivatives of pyrazine-2,3-dicarbonitrile, were prepared using a nucleophilic aromatic ubstitution reaction between 2,6-diisopropylphenol or 2,6-diphenylphenol and 5,6- dichloropyrazine-2,3-dicarbonitrile. Analysis of the resulting AzaPcs by UV/Visible and 1H NMR spectroscopy confirms that steric isolation of the AzaPc cores was enforced both in solution and in the solid state. X-ray diffraction studies of single crystals of the AzaPcs reveal that solvent inclusion takes place in each case. Of particular significance is the finding that the zinc derivative of 2,3,9,10,16,17,23,24-octa- (2,6-diisopropylphenoxy)octaazaphthalocyanine provides nanoporous cubic crystals,containing massive (8 nm3) solvent-filled voids,sim ilar to those of the analogous phthalocyanine derivative. Exchange of the included solvent within the voids can be readily achieved by using a number of alternative solvents including water. Based on the observed loading of included water,the internal volume of this nanoporous cubic crystal appears to be more hydrophilic than its phthalocyanine counterpart.