Reversible solid-gas and solid-solid transformation of lead(II)-phenylalanine coordination polymers

Abstract A reversible crystal to crystal structural transformation of lead(II) complex; [Pb(OH 2 ) 2 (Phe) 2 (NO 3 )] n [NO 3 ] ( 1 ), (Phe:L-phenylalanine), to coordination polymer 2D [Pb(phe) 2 ] n ( 2 ); has been observed upon solid–gas and solid–solid reactions of compound 1 to compound 2 and then 2 to 1 . A lead(II) supramolecular (1), polymerizes on grinding the solid with 1 mmol NaOH and also with NH 3 vapors to form the 2D coordination polymer (2). Solid–gas reaction has been verified by PXRD and IR spectroscopy. Pb 3 O 4 and mixture phase of PbO nanoparticles were obtained by thermal decomposition of compounds 1 and 2 by direct calcinations at 400 °C for 4 h. These nanoparticles were characterized by powder X-ray diffraction (PXRD) and scanning electron microscopy (SEM).