Solid state structural transformation of 1D to intermediate 2D and then to 3D porous coordination polymer by anion replacement; new precursors for preparation of PbCl2, Pb3O2Cl2 and PbO nanoparticles

Abstract

A reversible anion exchange of 1D lead(II) coordination polymers with the ligand 2,5-bis(4-pyridyl)-3,4-diaza-2,4-hexadiene (4-bpdh), from [Pb(4-bpdh)Cl₂]_n (1) to intermediate 2D [Pb(4-bpdh)(Cl)(NO₃)]_n (2) and then 3D porous coordination polymer [Pb(4-bpdh)(NO₃)₂(H₂O)]_n (3) by solid state anion replacement processes under mechanochemical reactions, have been studied. The reversible solid state structural transformations of compound 1 to compound 2 and then 3 by anion replacement have been verified by PXRD and IR spectroscopy. PbCl₂, Pb₃O₂Cl₂ and PbO nanoparticles were obtained by thermal decomposition of compounds 1, 2 and 3 in oleic acid as surfactant at 180 °C under an air atmosphere, respectively. These nanoparticles were characterized by powder X-ray diffraction (PXRD) and scanning electron microscopy (SEM).