Whereas 2,6-diisopropyl- and 2,6-dimethylphenyl-phosphate forms a 1-D chain, 2,6-diisopropyl-4-amino-phenylphosphate crystallizes as two different 3-D supramolecular aggregates. The first pseudopolymorph 1a is a porous framework built around a rare water-dimer template that undergoes single-crystal to single-crystal transformations to yield desolvated form 1b. The second-pseudopolymorph 1c, obtained by re-crystallisation of 1a in methanol, is a dense 3-D framework.