A nanoporous network polymer derived from hexaazatrinaphthylene with potential as an adsorbent and catalyst support

The synthesis and properties of a nanoporous network polymer incorporating 5,6,11,12,17,18-hexaazatrinapthylene (Hatn) as the rigid functional unit is described. This material is readily prepared from the efficient dibenzodioxane forming reaction between 2,3,8,9,14,15-hexachloro-5,6,11,12,17,18- hexaazatrinaphthylene and 5,5′,6,6′-tetrahydroxy-3,3,3′, 3′-tetramethyl-1,1′-spirobisindane and exhibits a high BET surface area (775 m² g^-1) similar to that obtained from related nanoporous networks based on phthalocyanine and porphyrin macrocycles. The ability of the Hatn unit to bind to metal ions was shown by the sequential binding of three palladium(II) dichloride moieties to a soluble model Hatn compound using a ¹H NMR titration experiment. When exposed to an excess of palladium(II) dichloride in chloroform solution, the Hatn nanoporous network is shown to adsorb 3.9 mmol g^-1 of the metal complex. The resulting material retains porosity (BET surface area = 347 m² g ^-1) and should be useful as a heterogeneous catalyst. The Hatn network polymer is also shown to be effective for the adsorption of phenol from aqueous solution with a maximum adsorption of 5 mmol g^-1, which is a significant improvement over the performance of activated carbon reported in similar studies.