Synthesis, characterization and X-ray structural studies of three hybrid inorganic–organic compounds: Silver(I)-, lead(II)- and tris(phenanthroline)copper(II)- 2,6-naphthalenedisulfonate (2,6-nds)

Abstract

Three new hybrid inorganic–organic compounds of silver(I), Ag2(2,6-nds), 1, lead(II), [Pb(2,6-nds)·H2O]n, 2 and copper(II), [Cu(phen)3](2,6-nds)·11H2O, 3, have been synthesized by reacting appropriate reactants in aqueous medium. All the three compounds were characterized on the basis of elemental analyses, spectroscopic techniques (FT-IR, NMR, EPR and NIR-Vis-UV), thermogravimetric analyses and X-ray powder diffraction studies. Single crystal X-ray structure determination of compound 2 (Monoclinic, P 21/c) revealed a polymeric structure in which lead(II) is seven coordinated by six sulfonato oxygen atoms and one oxygen atom of water molecule where as compound 3 (Triclinic, P1¯) revealed the existence of discrete ions i.e. [Cu(phen)3]2+ cation, 2,6-naphthalenedisulfonate (2,6-nds) anion and eleven water molecules of crystallization. These water molecules in wide channels show intermolecular non-covalent interactions with disulfonate anion and [Cu(phen)3]2+ cationic layer, leading to crystal lattice stabilization. The d–d bands found in diffuse-reflectance electronic spectrum arise from 2A1g (dx2−y2)>2A2g (dz2)≈2B1g (dxy)>2B2g (dxy)≈2B3g (dyz) transitions. A rare resolution of copper hyperfine splitting of powder EPR spectrum is observed only at low temperature.