Exploring the Role of Strong Intramolecular Coordination of the 2‐(2'‐pyridyl)phenyl Group in Heavy Main Group Halides: Insights from Synthesis, Structural, and Bonding Analyses. Issue 22 (28th May 2020) - Deka, Rajesh
Abstract : By the transmetallation of ppyHgCl [ppy = 2‐(2'‐pyridyl)phenyl] (1 ) with SnCl4 and SbCl3, the synthesis of the monoorgano main group halides, [ppySnCl3 (H2 O)]· 2(0.5diox) (diox = 1, 4‐dioxane) [2 (H2 O)]· 2(0.5diox) and [ppySbCl2 ] (3 ) was achieved. The reaction of 1 with BiCl3 does not give the analogous monoorganobismuth dichloride. Instead, it results in the formation of [(ppy)2 Bi] + · [ppyBiCl3 ] – (4 ). Reactions of (ppy)2 Te and (ppyTe)2 with SO2 Cl2 and Br2 result in the formation of ppyTeCl (5 ) and ppyTeBr (6 ) respectively. All the synthesized compounds were characterized by multi‐nuclear NMR spectroscopy ( 1 H, 13 C, 119 Sn, and 125 Te), FT‐IR spectroscopy, ESI‐MS, CHN analysis, and single‐crystal X‐ray diffraction studies. The molecular structures of 2 –6 reveal strong intramolecular coordination of the N‐atoms of the pendant arms with the main group element centers. DFT calculations; including Natural Bond Order (NBO), Electron Localization Function (ELF), Electrostatic Surface Potential (ESP) and Atoms in Molecules (AIM) infer that the stability of 2 –6 relies on the σ‐hole participation of the element center with the N‐lone pair of the pyridyl arm. Abstract : Using the strong intramolecular coordination ability of the N atom of the 2‐(2'‐pyridyl)phenyl (ppy) group, monoorgano main group halides of period 5, namely [ppySnCl3 (H2 O)]· 2(0.5diox) (diox = 1, 4‐dioxane) and [ppySbCl2 ] are synthesized. The attempted synthesis of corresponding Bi congener results in the formation of diorganobismuthenium ion stabilized by a monoorganobismuthenium cation, [(ppy)2 Bi] + · [ppyBiCl3 ] – .