Dynamic crystal-to-crystal transformation of 1D to 2D lead(ii) coordination polymers by de- and rehydration with no change in the morphology of nano-particles

Abstract

A reversible crystal-to-crystal transformation of a 1D lead(II) coordination polymer to a 2D lead(II) coordination polymer with the ligand 1,2-di-(4-pyridyl)-ethylene (bpe), [Pb₂(μ-bpe)₃(μ-NO₃)₂(NO₃)₂(H₂O)₂]_n (1) to [Pb₂(μ-bpe)₃(μ-NO₃)₂(NO₃)₂]_n (2), by de- and rehydration has been observed and the structures of 1 and 2 were determined by single crystal X-ray diffraction. The thermal stabilities of compounds 1 and 2 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 monophasic products. Nano-particles of compound 1 were synthesized by a sonochemical process and characterized by scanning electron microscopy (SEM), powder X-ray diffraction, IR spectroscopy and elemental analyses. The SEM images showed that no change in the morphology occurs during this dynamic crystal-to-crystal conversion.