Issue 9, 2023

On pyridine chloronium cations


We present the first solid-state structural evidence of mono- and bis(pyridine)chloronium cations. The latter was synthesized from a mixture of pyridine, elemental chlorine and sodium tetrafluoroborate in propionitrile at low temperatures. The mono(pyridine) chloronium cation was realized with the less reactive pentafluoropyridine, using ClF, AsF5, and C5F5N in anhydrous HF. During the course of this study, we also investigated pyridine dichlorine adducts and found a surprising disproportionation reaction of chlorine that depended on the substitutional pattern of the pyridine. Electron richer dimethylpyridine (lutidine) derivatives favor full disproportionation into a positively and a negatively charged chlorine atom which forms a trichloride monoanion, while unsubstituted pyridine forms a 1 : 1 py·Cl2 adduct.

Graphical abstract: On pyridine chloronium cations

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Article information

Article type
Edge Article
07 Dec 2022
04 Feb 2023
First published
06 Feb 2023
This article is Open Access

All publication charges for this article have been paid for by the Royal Society of Chemistry
Creative Commons BY license

Chem. Sci., 2023,14, 2325-2329

On pyridine chloronium cations

P. Pröhm, W. Berg, S. M. Rupf, C. Müller and S. Riedel, Chem. Sci., 2023, 14, 2325 DOI: 10.1039/D2SC06757A

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