Elemental and supramolecular diversity of nanoporous phthalocyanine crystals

Phthalocyanines (Pcs) have a wide variety of applications as colorants, photodynamic therapeutics, photovoltaic materials, catalysts etc. Pcs tend to co-facially aggregate due to the π – π interactions between their aromatic macrocycles, which may hinder certain applications. The insertion of 2,6-di-iso-propylphenoxy substituents at the peripheral sites of the Pc [(dipPhO)8Pc] proved successful in preventing aggregation between the macrocycles while the bulky substituents created accessible voids towards the active metal centre. Upon crystallisation of various metal (dipPhO)8Pc derivatives, clathrates with an interesting cubic structure, where the volume occupied by the crystallisation solvent amounts to around 40% of the unit cell, were obtained. Suitably sized bidentate ligands act as wall-ties to stabilise the crystal structure upon removal of the solvents that otherwise would cause loss of crystallinity. We have found that there is an astonishing range of metal cations, axial ligands and molecular wall-ties that are compatible with the formation of the porous crystal. Preliminary data using a gas cell for the in-situ analysis of O2, NO and CO binding to the metal cation will be reported. In addition, the co-crystallisation of (dipPhO)8Pc with tetraphenyl porphyrin (H2TPP) and the in-situ incorporation of bidentate ligands and of metals in the macrocycle of the TPP will be demonstrated

Ligand effects on gas adsorption in nanoporous phthalocyanine crystals

X-ray diffraction is used to study the sorption of CO and NO in two phthalocyanine nanoporous crystals (PNCs) with 4,40 bipyridine or 4,40 bipyrimidine trans coordinated to open Co2+ sites, demonstrating how the trans coordinated ligands influence the gas sorption properties and structures of the PNCs