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A porous supramolecular framework has been for the first time revealed to undergo interpenetration in crystal and non-interpenetration in solution. A new supramolecular organic framework Bu-SOF has been constructed from the co-assembly of a tetracationic tetrahedral monomer and cucurbit[8]uril (CB[8]) in water through the encapsulation of two anti-parallel n-butyl chains by CB[8]. X-ray diffraction analysis reveals that Bu-SOF forms 3-fold interpenetrated networks in crystals grown by evaporation of its solution in water. 1H NMR, dynamic light scattering and isothermal titration calorimetric experiments confirm that Bu-SOF is also formed in water. Solid samples, prepared by lyophilizing the aqueous solution of Bu-SOF, can adsorb nanoscaled organic dyes, supporting the porosity of the framework and thus non-interpenetration in solution. The avoidance of interpenetration of Bu-SOF in solution has been attributed to the filling of water inside the porous framework as well as the electrostatic repulsion of the appended bipyridinium units of the tetrahedral building block.

Manganese oxides, which are easily prepared, simple to use and capable of being recycled, have been employed as catalyst in the selective oxidation of toluene to benzoic acid for the first time. Molecular oxygen was used as oxidant under additive- and solvent-free conditions. As a result, 39% conversion of toluene and 93% selectivity of benzoic acid were achieved.