p-QUINONE (p-BENZOQUINONE)

p-QUINONE

PRODUCT IDENTIFICATION

CAS NO.

106-51-4

p-QUINONE

EINECS NO.

203-405-2

FORMULA

C₆H₄(=O)₂

MOL WT.

108.1

H.S. CODE

TOXICITY

Oral rat LD50: 100mg/kg

SYNONYMS

2,5-Cyclohexadiene-1,4-dione; 1,4-Benzoquinone;

p-Benzoquinone; 1,4-dioxybenzene; Cyclohexadiene-1,4-dione; Quinone; Benzo-chinon (German); Chinon (Dutch, German); P-chinon (German); 1,4-diossibenzene (Italian); 1,4-dioxy-benzol (German)

SMILES

CLASSIFICATION

PHYSICAL AND CHEMICAL PROPERTIES

PHYSICAL STATE

yellow to green crystalline solid with pungent odor

MELTING POINT

BOILING POINT

116 C

SPECIFIC GRAVITY

1.32

SOLUBILITY IN WATER

Slightly Soluble

VAPOR DENSITY

3.7

REFRACTIVE INDEX

AUTOIGNITION

435 C

NFPA RATINGS

Health: 2; Flammability: 2 ; Reactivity: 0

FLASH POINT

74 C

STABILITY

Stable under ordinary conditions

APPLICATIONS

Quinone is a group of aromatic compounds containing two opposite carbonyl groups (C=O) and the other two pairs of carbon atoms linked by vinylene group(-CH=CH) in a six-membered unsaturated ring. The carbonyl groups are located in different rings and form various chemical structures which offer important roles to colours. Quinones are used in photography and dye manufacture. Quinones occur benzoquinones, naphthoquinones, anthraquinones, and polycyclic quinones. Though quinones are found in plants and in a few animals, they usually are prepared by oxidation of aromatic amines, polyhydric phenols, and polynuclear hydrocarbons.The reduction of quinone to the corresponding dihydroxy form is an important characteristic reaction. In acidic solution, p-benzoquinone is reduced reversibly to hydroquinone. The so-called quinhydrone electrode, containing equimolar solution of quinone and hydroquinone, is used to determine hydrogen ion concentrations depends on the oxidation-reduction reactions. Hydroquinone and its derivatives used principally in photographic dye chemicals, in medicine, as an antioxidant, and in paints, varnishes, and motor fuels and oils. Hydroquinone and certain derivatives are also used as polymerization inhibitors by direct reacting with peroxy-free radical to tie up free radicals. p-Benzoquinone is used as a fungicide and to make dyes and other agrochemicals. It is also an inhibitor especially for vinyl monomers and unsaturated polyester resins, and cross-linking agent.

Examples of quinone substances

Quinone substances	Description
Ansamycin antibiotics	Chemotherapeutic
Anthracycline	Chemotherapy
Anthraquinone	Polycyclic aromatic compound
Alizarin	Anthraquinone dye
Quinones	Oxidants in organic synthesis
Blattellaquinone	Pheromone
Chloranil	Oxidant, Pesticide
Coenzyme Q10	Vitamin-like substance
Emodin	Enzyme inhibitors
Carminic acid	Anthraquinone dye
Indolequinones	Indoles
Lapachol	Vitamin K-like substance
Lawsone	Dye
Menadione	Vitamin K1
Mitomycin	Chemotherapeutic
Naphthoquinones	Aromatic ketone
Pixantrone	Immunosuppressant
Plastoquinone	Photosynthesis
Pyrroloquinoline quinone	Enzyme cofactor
Tanespimycin	Antineoplastic
Vitamin K	Vitamin

SALES SPECIFICATION

APPEARANCE

yellow to green crystalline solid

ASSAY

99.5% min

ASH

0.2% max

WATER

0.1% max

TRANSPORTATION

PACKING

HAZARD CLASS

6.1

UN NO.

2587

GENERAL DESCRIPTION OF DIKETONE

Diketone is a molecule which contains two ketone carbonyl groups. Diacetyl (CH₃COCOCH₃), 2,3-butadione, is the simplest aliphatic diketone. It is an alpha-diketone which has two ketone groups side-by-side. Usually, alpha-diketone imparts a carmel like or buttery flavor. Diketone compounds take a role in creating various fragrances. Bezil (C₆H₅COCOC₆H₅₎is an aromatic diketone, the fundamental structure of photo sensitive molecule which is broken down into free radicals upon exposure to ultraviolet radiation. Acetoacetone is a beta-diketone which two ketones are separated only by one carbon. The beta-ketone is stable as a conjugated enol rather than a diketone due to the delocalization which makes the counterion more stable and less likely to regain the proton. Ascorbic acid is an example of enol compound. Enol compounds form complexes with many transition metal ions. These compounds are readily soluble in organic solvents. They are widely used as chelating agents, ligands, and catalyst precursors. Acetoacetic acid and its esters contain active methylene groups which have relatively acidic alpha-protons due to H atom adjacent to two carbonyl groups. The reactivity of its methylene group provide the sequence of reactions of alkylation, hydrolysis of the esters and decarboxylation resulting in substituted ketones. Acetoacetic acid derivatives are important aliphatic parts adjoining azo dyes and pigments. Aacetoacetate is one of Ketone bodies which are the end-products of rapid or excessive fatty acid breakdown in the human body. Para-benzoquinone and its derivatives belong to 1,4-diketone family. Benzoquinone is used as an oxidizing agent in organic chemistry and is a common constituent of biologically molecules like Vitamin K1. Quinones serves as electron acceptors in electron transport chains such as in photosynthesis, and aerobic respiration. Diketene derivatives find versatile applications in making biomolecules, agrochemicals, dyes, pigments, pharmaceuticals including vitamins, and stabilizers for PVC and polyester. They are used as components for fragrances and as solvents. Diketones undergo the reversible and irreversible addition reactions include;

Aldol Reactions
Alkylation of Enolate Anions
Clemmensen Reduction
Cyanohydrin Formation
Enamine Formation
Hemiacetal and Acetal Formation
Hydration Formation
Imine Formation
Wolff-Kishner Reduction

OTHER INFORMATION