Hysteretic sorption of light gases by a porous metal-organic framework containing tris(para-carboxylated) triphenylphosphine oxide

摘要

The porous metal-organic framework (MOF) PCM-4, based on tris(para-carboxylated) triphenylphosphine oxide, contains atypical, polar organic substituents; the material exhibits a hysteretic sorption of Ar, N_2 and O_2, and demonstrates the advantage of ligands of this type. The intensive current interest in the rational design of porous metal-organic frameworks (MOFs) has shown how various organic 'linkers' may be tethered to metal (oxide/hydroxide) 'nodes' to form new functional materials. Examples that retain structural integrity and porosity upon removal of a guest solvent have the potential for applications in gas storage/separation, catalysis and polymerization, amongst others. Linear organic linkers, such as 4,4'-bipyridine, 1,4-benzene dicarboxylate, etc., have provided successful routes to large families of porous networks with tunable pore dimensions. Gas sorption studies using various probe gases and limited neutron scattering data6 have begun to elucidate relationships between framework composition and gas uptake characteristics. New generations of porous MOFs employ more exotic organic groups, which afford novel framework topologies that contain more polar organic substituents and/or unsaturated metal sites8 to enhance gas storage and guest selectivity.