What is "picoline"

Picoline \Pic"o*line\, n. [L. pix, picis, pitch + oleum oil + -ine.] (Chem.) Any one of three isometric bases ( C6H7N) related to pyridine, and obtained from bone oil, acrolein ammonia, and coal-tar naphtha, as colorless mobile liquids of strong odor; -- called also methyl pyridine.

n. (context organic compound English) Any of three isomeric methyl derivatives of pyridine, analogous to toluene

Picoline refers to three different methyl pyridine isomers, all with the chemical formula C H N and a molar mass of 93.13 g mol. All three are colourless liquids at room temperature and pressure, with a characteristic smell similar to pyridine. They are miscible with water and most organic solvents. Data for the three compounds are summarized in the table.

Name(s)

CAS#

m.p. (°C)

b.p. (°C)

pK of pyridinium ion

structure

2-Methylpyridine, α-picoline, 2-picoline

[109-06-8]

-66.7

129.4

5.96

[[Image:2-Picoline Structural Formula V1.svg|90px|

α-picoline

]]

3-Methylpyridine, β-picoline, 3-picoline

[108-99-6]

-18

141

5.63

[[Image:3-Picoline Structural Formula V1.svg|90px|

β-picoline

]]

4-Methylpyridine, γ-picoline, 4-picoline

[108-89-4]

3.6

145.4

5.98

[[Image:4-Picoline Structural Formula V1.svg|48px|

γ-picoline

]]

The CAS number of an unspecified picoline isomer is [1333-41-1]