Solid-state multinuclear magnetic resonance and X-ray crystallographic investigation of the phosphorus...iodine halogen bond in a bis(dicyclohexylphenylphosphine)(1,6-diiodoperfluorohexane) cocrystal

• Published in: Acta crystallographica Section B, Structural science, crystal engineering and materials Vol. 78; no. Pt 3 Pt 2; p. 557
• Main Authors: Zheng, Dan Ni, Szell, Patrick M J, Khiri, Safaa, Ovens, Jeffrey S, Bryce, David L
• Format: Journal Article
• Language: English
• Published: England 01.06.2022
• Subjects: cocrystal; mechanochemistry; solid-state NMR; crystallographic disorder; halogen bonding
• ISSN: 2052-5206
• DOI: 10.1107/S2052520622004322

Halogen bonding to phosphorus atoms remains uncommon, with relatively few examples reported in the literature. Here, the preparation and investigation of the cocrystal bis(dicyclohexylphenylphosphine)(1,6-diiodoperfluorohexane) by X-ray crystallography and solid-state multinuclear magnetic resonance spectroscopy is described. The crystal structure features two crystallographically unique C-I...P halogen bonds [d = 3.090 (5) Å, 3.264 (5) Å] and crystallographic disorder of one of the 1,6-diiodoperfluorohexane molecules. The first of these is the shortest and most linear I...P halogen bond reported to date. C, F, and P magic angle spinning solid-state NMR spectra are reported. A P chemical shift change of -7.0 p.p.m. in the cocrystal relative to pure dicyclohexylphenylphosphine, consistent with halogen bond formation, is noted. This work establishes iodoperfluoroalkanes as viable halogen bond donors when paired with phosphorus acceptors, and also shows that dicyclohexylphenylphosphine can act as a practical halogen bond acceptor.