Porous crystal derived from a tricarboxylate linker with two distinct binding motifs

The use of a reduced symmetry organic linker for the preparation of porous coordination polymers is demonstrated. The solvothermal reaction of the unsymmetrically substituted biaryl compound biphenyl-3,4',5-tricarboxylic acid with Cu(II) ions produces a [3,4,6]-connected coordination polymer exhibiting very high porosity and surface area (S-Langmuir = 3100 m(2)/g). A striking feature of the structure is its incorporation, in a single material, of both the ubiquitous dinuclear Cu(II) paddlewheel motif and the rarely observed trinuclear Cu(II) cluster. Saturation H-2 uptake, measured at 77 K, shows an excess gravimetric uptake of 5.7 wt % at 45 bar with a steep rise at low pressures.