A new hemidirected lead(II) complex extended in holodirected one-dimensional polymer by secondary Pb–O interactions: A precursor for preparation of PbO nanoparticles, and DFT study

Abstract

A new 1D extended lead (II) coordination polymer [Pb(2-apinh) (NO3)2]n (1), (2-apinh = 2-acetylpyridine isonicotinoylhydrazone) has been synthesized by a thermal gradient method in a branched tube and characterized by elemental analysis, FT-IR, thermal analysis and single crystal X-ray diffraction. The single-crystal X-ray data show that the coordination number of Pb(II) in [Pb(2-apinh)(NO3)2] moieties is five (PbN2O3) with a stereo-chemically active lone pair on lead(II), and thus its coordination sphere is hemidirected. Moreover, each [Pb(2-apinh) (NO3)2] unit is linked by the secondary Pb⋯O7i interactions to form 1D extended coordination polymer, which approximately completes the Pb(II) coordination sphere with a Pb⋯O5 interaction (PbN2O5) in a holodirected geometry. In the solid state, the 1D chains are connected through non-covalent interactions, such as π⋯π stacking, C–H⋯π and C–H⋯O interactions to form 3D supramolecular network. Moreover, compound 1 exhibits 1D left-handed helical infinite chains along the c axis by non-covalent interactions. The structure of 1 has been optimized by density functional theory. The calculated structural parameters and IR spectra for the complex are in accordance with its crystal structure. PbO nanoparticles were obtained by thermolysis of 1 at 180 °C with oleic acid as a surfactant and characterized via FT-IR, XRD, and SEM.