Diaminopyridine Hg(II)-based 1D supramolecular polymer: Crystallographic and computational insights into spodium bonding

Abstract

A new Hg(II)-based one dimensional supramolecular polymer with a molecular formula of [(C5H3N(NH2)2Cl2Hg)]n (1) has been synthesized and characterized using microanalysis, FTIR, UV–Vis., multinuclear NMR and single crystal X-ray diffraction. The X-ray diffraction reveals initially a three coordinated geometry around the Hg(II) centre, coordinated covalently with two non-coplanar chlorine atoms and one nitrogen atom of the 2,6-diamino pyridine ring. Furthermore, two more chlorine centers form a bridge between two Hg centers through the Hg⋯Cl spodium bond interaction to furnish a pseudo trigonal bipyramidal geometry (τ5 ​= ​0.957) in a supramolecular polymer. The solid state architecture of the polymer is stabilised by different weak interactions and it also exhibit unconventional Hg⋯Cl spodium and Hg⋯H–N interactions. The nature of these interactions have been investigated using Hirshfeld surface analyses, density functional theory and quantum theory of atoms in molecules (QTAIM) studies. The emission studies for the compound in both solution and solid phase have also been executed.