Title: Pyridine
CAS Registry Number: 110-86-1
Molecular Formula: C5H5N
Molecular Weight: 79.10
Percent Composition: C 75.92%, H 6.37%, N 17.71%
Literature References: Discovered in coal tar: T. Anderson, Ann. 60, 86 (1846). Physical data: B. A. Middleton, J. R. Partington, Nature 141, 516 (1938). Acute toxicity study: H. F. Smyth Jr. et al., Arch. Ind. Hyg. Occup. Med. 4, 119 (1951). Books: H. Maier-Bode, Das Pyridin und Seine Derivate in Wissenschaft und Technik (Edwards Bros., Ann Arbor, Mich., 1943); Hill in Chemistry of Coal Utilization vol 2, H. H. Lowry, Ed. (Wiley, New York, 1945), Chapter 27; The Chemistry of Heterocyclic Compounds vol. 14, a series of books entitled "Pyridine and its Derivatives": Parts 1-4, E. Klingsberg, Ed. (1960-1964); Suppl. Parts 1-4, R. A. Abramovitch, Ed. (1974-1975); Part 5, G. R. Newkome, Ed. (1984) (Wiley-Interscience, New York). Review: G. L. Goe in Kirk-Othmer Encyclopedia of Chemical Technology vol. 19 (Wiley-Interscience, New York, 3rd ed., 1982) pp 454-483. Review of commercial synthesis and uses of pyridine and derivatives: D. J. Berry, Spec. Chem. 3, 13 (1983); of occurrence of pyridine and derivatives in foods, tobacco and essential oils: G. Vernin, Perfum. Flavor. 7, 23-26 (1982); of use in the study of surface properties of transition metal oxides: M. C. Kung, H. H. Kung, Catal. Rev. Sci. Eng. 27, 425-460 (1985). Review of toxicology and environmental fate: A. Jori et al., Ecotoxicol. Environ. Saf. 7, 251 (1983); and human exposure: Toxicological Profile for Pyridine (PB93-110831, 1992) 108 pp.
Properties: Flammable, colorless liq; characteristic disagreeable odor; sharp taste. d420 0.98272. Flash pt, closed cup: 68°F (20°C). mp -41.6°. bp 115.2-115.3°. nD20 1.50920. Dipole moment in benzene: 2.26. Forms an azeotropic mixture with 3 mols water, boiling at 92-93°. Volatile with steam. Miscible with water, alcohol, ether, petr ether, oils and many other organic liquids. Good solvent for many organic and inorganic compds. Weak base; forms salts with strong acids. pKa 5.19. pH of 0.2 molar soln in H2O: 8.5. LD50 orally in rats: 1.58 g/kg (Smyth).
Melting point: mp -41.6°
Boiling point: bp 115.2-115.3°; Forms an azeotropic mixture with 3 mols water, boiling at 92-93°
Flash point: Flash pt, closed cup: 68°F (20°C)
pKa: pKa 5.19
Index of refraction: nD20 1.50920
Density: d420 0.98272
Toxicity data: LD50 orally in rats: 1.58 g/kg (Smyth)
CAUTION: Potential symptoms of overexposure are headache, nervousness, dizziness and insomnia; nausea, anorexia; eye irritation; dermatitis; liver and kidney damage. See NIOSH Pocket Guide to Chemical Hazards (DHHS/NIOSH 97-140, 1997) p 272.
Use: As solvent for anhydr mineral salts. Synthetic intermediate in laboratory and industry. |