Various Unique Coordination Patterns of Hg and DFT Calculations To Determine the Formation of a 3-D Supramoleculer Framework by Covalent and Noncovalent Interactions
By combining a large pi-conjugated bidentate ligand L: 3,6-dipyrazole-N-ethylcarbazole with HgI2, an extraordinary supramolecular coordination polymer, [Hg4L2I8](infinity), has been prepared. The crystal structures of the ligand and its coordination polymer were determined by X-ray crystallography, which shows three varied coordination modes especially the rare asymmetric quadruply bridged trinuclear moieties in [Hg4L2I8](infinity). Density functional theory (DFT) calculations (ADF) performed on model dimers show the roles of covalent and noncovalent interactions in establishing the three-dimensional architecture.