Pyridinium dichromate Property

Melting point:

152-153 °C(lit.)

Density 

1.71[at 20℃]

vapor pressure 

0Pa at 25℃

storage temp. 

Inert atmosphere,Room Temperature

solubility 

soluble in DMSO

form 

Crystalline Powder

color 

Orange to brown

Water Solubility 

soluble

Sensitive 

Hygroscopic

Exposure limits

OSHA: Ceiling 0.1 mg/m3
NIOSH: IDLH 15 mg/m3; TWA 0.0002 mg/m3

InChIKey

BNSOYWDFFBDEFB-UHFFFAOYSA-L

LogP

-3.7 at 20℃

CAS DataBase Reference

20039-37-6(CAS DataBase Reference)

EPA Substance Registry System

Chromic acid (H2Cr2O7), compd. with pyridine (1:2) (20039-37-6)

Safety

Hazard Codes 

O,T,N,Xn,F,Xi

Risk Statements 

49-8-43-50/53-61-60-46-45-20/21/22-40-36/37/38-34-11

Safety Statements 

53-45-60-61-37-29-24-17-36/37/39-27-22-26

RIDADR 

UN 1479 5.1/PG 2

WGK Germany 

2

F 

3

TSCA 

Yes

HazardClass 

5.1

PackingGroup 

II

HS Code 

29333100

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Danger

Hazard statements

H228Flammable solid

H272May intensify fire; oxidizer

H314Causes severe skin burns and eye damage

H317May cause an allergic skin reaction

H410Very toxic to aquatic life with long lasting effects

Precautionary statements

P210Keep away from heat/sparks/open flames/hot surfaces. — No smoking.

P260Do not breathe dust/fume/gas/mist/vapours/spray.

P280Wear protective gloves/protective clothing/eye protection/face protection.

P303+P361+P353IF ON SKIN (or hair): Remove/Take off Immediately all contaminated clothing. Rinse SKIN with water/shower.

P305+P351+P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.

Pyridinium dichromate Chemical Properties,Usage,Production

Chemical Properties

Orange solid

Uses

Pyridinium dichromate (PDC) is an orange colored solid used as an oxidizing agent.
Oxidizing agent for conversion of primary alcohols to aldehydes and ketones, acetals to esters, and didehydroketones to enones in the presence of tert-butyl hydroperoxide.
Pyridinium Dichromate may be used as an alternative to PCC in nucleoside and carbohydrate oxidation, particularly for fragile molecules. PDC can also be used in conjunction with tertbutylhydroperoxide for a variety of oxidative transformations.

Uses

Pyridinium dichromate acts as a strong oxidizing agent used in the conversion of primary alcohols and secondary alcohols to aldehydes and ketones respectively. It plays an important role in the oxidation of unsaturated tertiary alcohols, silyl ethers, the carbon-boron bond, and oximes. Further, it is used in the conversion of acetals to esters and didehydroketones to enones in the presence of tert-butyl hydroperoxide.

Definition

ChEBI: Pyridinium dichromate is a pyridinium salt that is the dipyridinium salt of dichromic acid. It is a strong oxidizing agent which can convert primary and secondary alcohols to aldehydes and ketones respectively. It has a role as an oxidising agent. It contains a dichromate(2-).

Preparation

Pyridinium dichromate can be obtained by gradual addition of a solution of chromic anhydride (Cr2O3) in water to pyridine in ice cold conditions.

Flammability and Explosibility

Flammable

Purification Methods

Dissolve it in the minimum volume of H2O and add 5 volumes of cold Me2CO and cool to -20o. After 3hours the orange crystals are collected, washed with a little cold Me2CO and dried in a vacuum. It is soluble in dimethylformamide (0.9g/mL at 25o), and in H2O, and has a characteristic IR with max at 930, 875, 765, 730 and 730 cm-1. [Corey & Schmidt Tetrahedron Lett 399 1979, Coats & Corrigan Chem Ind (London) 1594 1969.] (Possible CARCINOGEN.) § Available commercially on a polymer support.