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Towards a Stronger Halogen Bond Involving Astatine: Unexpected Adduct with Bu 3 PO Stabilized by Hydrogen Bonding
Author(s) -
Liu Lu,
Guo Ning,
Champion Julie,
Graton Jérôme,
Montavon Gilles,
Galland Nicolas,
Maurice Rémi
Publication year - 2020
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201905389
Subject(s) - adduct , chemistry , halogen bond , halogen , astatine , hydrogen bond , ligand (biochemistry) , lewis acids and bases , quadruple bond , crystallography , molecule , stereochemistry , bond order , bond length , crystal structure , organic chemistry , physics , alkyl , receptor , biochemistry , quantum mechanics , voltage , catalysis
Abstract The halogen bond is a powerful tool for the molecular design and pushing the limits of its strength is of major interest. Bearing the most potent halogen‐bond donor atom, astatine monoiodide (AtI) was recently successfully probed [ Nat. Chem . 2018 , 10 , 428–434]. In this work, we continue the exploration of adducts between AtI and Lewis bases with the tributylphosphine oxide (Bu 3 PO) ligand, revealing the unexpected experimental occurrence of two distinct chemical species with 1:1 and 2:1 stoichiometries. The 1:1 Bu 3 PO⋅⋅⋅AtI complex is found to exhibit the strongest astatine‐mediated halogen bond so far (with a formation constant of 10 (4.24±0.35) ). Quantum chemical calculations unveil the intriguing nature of the 2:1 2Bu 3 PO⋅⋅⋅AtI adduct, involving a halogen bond between AtI and one Bu 3 PO molecular unit plus CH⋅⋅⋅O hydrogen bonds chelating the second Bu 3 PO unit.