Collins reagent

This article is about the oxidizing reagent. For the oxidation reaction, see Collins oxidation.
Collins reagent
Names
IUPAC name
Pyridine - trioxochromium (2:1)
Other names
Dipyridine chromium(VI) oxide[1]
Identifiers
3D model (JSmol)
ChemSpider
  • InChI=1S/2C5H5N.Cr.3O/c2*1-2-4-6-5-3-1;;;;/h2*1-5H;;;;
    Key: NPRDHMWYZHSAHR-UHFFFAOYSA-N
  • InChI=1/2C5H5N.Cr.3O/c2*1-2-4-6-5-3-1;;;;/h2*1-5H;;;;/r2C5H5N.CrO3/c2*1-2-4-6-5-3-1;2-1(3)4/h2*1-5H;
    Key: NPRDHMWYZHSAHR-RGHLCDNPAM
  • c1ccncc1.c1ccncc1.O=[Cr](=O)=O
Properties
C10H10CrN2O3
Molar mass 258.194
Appearance Red crystals[1]
Density 1.565 g/cm3
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Collins reagent is the complex of chromium(VI) oxide with pyridine in dichloromethane.[2] This metal-pyridine complex, a red solid, is used to oxidize primary alcohols to the corresponding aldehydes and secondary alcohols to the corresponding ketones. This complex is a hygroscopic orange solid.[1]

  1. ^ a b c Fillmore Freeman (2001). "Dipyridine Chromium(VI) Oxide". e-EROS Encyclopedia of Reagents for Organic Synthesis. doi:10.1002/047084289X.rd452m. ISBN 0471936235.
  2. ^ J. C. Collins, W.W. Hess (1972). "Aldehydes from Primary Alcohols by Oxidation with Chromium Trioxide: Heptanal". Organic Syntheses. 52: 5. doi:10.15227/orgsyn.052.0005.