Anion Influence on Transformations of a Nonporous 3D to Porous 3D Coordination Polymer

Abstract

Reversible anion-exchange of nonporous 3D lead(II) coordination polymers with ligand 2,5-bis(4-pyridyl)-3,4-diaza-2,4-hexadiene (4-bpdh), from [Pb(4-bpdh)(μ-NCS)<inf>2</inf>]<inf>n</inf> (1) to intermediate 3D [Pb(4-bpdh)(μ-NCS)(NO<inf>3</inf>)]<inf>n</inf> (2) and then porous 3D coordination polymers of [Pb(4-bpdh)(NO<inf>3</inf>)<inf>2</inf>(H <inf>2</inf>O)]<inf>n</inf> (3) and [Pb(4-bpdh)(NO<inf>3</inf>) <inf>2</inf>]<inf>n</inf> (4) 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 and 4 by anion-replacement have been verified by PXRD and IR spectroscopy. Pb <inf>5</inf>O<inf>4</inf>SO<inf>4</inf>, Pb<inf>2</inf>(SO<inf>4</inf>)O and PbO nanoparticles were obtained by thermal decomposition of compounds 1, 2 and 3, 4 at 600 °C under an air atmosphere, respectively. These nanoparticles were characterized by powder X-ray diffraction (PXRD) and scanning electron microscopy (SEM). © the Partner Organisations 2014.