Dynamic crystal-to-crystal conversion of a 3D-3D coordination polymer by de- and re-hydration

A reversible crystal-to-crystal transformation of a 3D lead(ii) coordination polymer with the ligand 4-pyridinecarboxylic acid (4-Hpyc), from Pb(4-pyc)(2)(H(2)O)](n) () to Pb(4-pyc)(2)](n) () by de- and re-hydration, has been observed and the structures of and were determined by single-crystal X-ray diffraction. The thermal stabilities of compounds and were studied by thermal, gravimetric and differential thermal analyses. Powder X-ray diffraction experiments showed that the phase transitions observed for the single crystals also occur in the batch powder samples and lead to mono phasic products.