Pyridinium chloride

Pyridinium chloride ^{[1] [2]}

Pyridinium chloride The chemical structure of pyridinium chloride
Names
IUPAC name Pyridinium chloride
Other names Pyridine hydrochloride
Identifiers
CAS Number	628-13-7  Y
3D model (JSmol)	Interactive image
ECHA InfoCard	100.010.026
EC Number	211-027-4
PubChem CID	69401
UNII	1U87419851  Y
CompTox Dashboard (EPA)	DTXSID6027262
InChI InChI=AOJFQRQNPXYVLM-UHFFFAOYSA-N
SMILES C1=CC=[NH+]C=C1.[Cl-]
Properties
Chemical formula	C5H6NCl
Molar mass	115.56 g/mol
Appearance	Hygroscopic white crystals
Density	1.34 g/cm3
Melting point	144 °C (291 °F; 417 K)
Boiling point	Decomposes
Solubility in water	85 g / 100 mL
Solubility	Soluble in chloroform, ethanol, insoluble in diethyl ether
Vapor pressure	1 (0 °C)
Acidity (pKa)	5
Hazards
Occupational safety and health (OHS/OSH):
Main hazards	Irritant
GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H302, H312, H315, H319, H332, H335
Precautionary statements	P261, P264, P270, P271, P280, P301+P312, P302+P352, P304+P312, P304+P340, P305+P351+P338, P312, P321, P330, P332+P313, P337+P313, P362, P403+P233, P405, P501
NFPA 704 (fire diamond)	2 0 0
Flash point	Non-flammable
Autoignition temperature	Non-flammable
Lethal dose or concentration (LD, LC):
LD50 (median dose)	1600 mg/kg (oral, rat)
Safety data sheet (SDS)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Pyridinium chloride is an organic chemical compound with a formula of C₅H₅NHCl.

Preparation

Pyridinium chloride can be produced by passing hydrogen chloride in pyridine dissolved in diethyl ether. The chemical formula is as follows:

C₅H₅N + HCl → C₅H₆N⁺Cl⁻ ↓

Acidity

Containing a pyridinium ion, pyridinium chloride has a pK_a of approximately 5, slightly more acidic than that of typical amines. This is due to the hybridization of the nitrogen: the nitrogen is sp² hybridized and more electronegative than those nitrogens in ammonium cations, which are sp³ hybridized. Hence they are stronger acids than amines and can be more easily deprotonated by bases. ^[3]

References

1. "Pyridine hydrochloride(628-13-7) MSDS Melting Point Boiling Point Density Storage Transport". ChemicalBook. Retrieved 2019-03-22.
2. Wilson, Michael W. (2001). "Pyridinium Chloride". Encyclopedia of Reagents for Organic Synthesis. John Wiley & Sons. doi:10.1002/047084289x.rp287m. ISBN   9780470842898.
3. "Pyridine: synthesis and reactivity | BrainyResort". Brainy Resort. 2016-11-08. Retrieved 2019-03-28.