Quinhydrone

Synonym(s):Hydroquinone: benzoquinone 1:1 complex;Quinhydrone

CAS NO.：106-34-3
Empirical Formula: C12H10O4
Molecular Weight: 218.21
MDL number: MFCD00010310
EINECS: 203-387-6
SAFETY DATA SHEET (SDS)
Update Date: 2025-01-27 09:38:02

What is Quinhydrone?

Chemical properties

a dark green crystalline powder which is a complex formed by benzoquinone and hydroquinone.

Quinhydrone is a general reagent used in potentiometric titrations. It can also be used as a π-acceptor in the formation of charge-transfer complex of analytes for spectrophotometric analysis.

Definition

ChEBI: Quinhydrone is an addition compound. It contains a 1,4-benzoquinone and a hydroquinone.

Definition

The so-called quinhydrone electrode, containing equivalent amounts of p-benzoquinone and hydroquinone, is used to determine hydrogen ion concentrations of unknown solutions. Hydroquinone is used principally as a photographic developing agent. The main advantages of the quinhydrone electrode are low internal resistance, rapid response, high accuracy, simplicity, free of errors due to the presence of nonreducing gases, and free of salt errors. Major limitations are that it contaminates the solution, cannot be used to monitor a flowing solution, the solution must be free of strong oxidizing and reducing agents, and it is limited to a pH range of 1 to 9. In alkaline solution, the weakly acidic H2Q is neutralized and is subject to oxidation by air and dissolved oxygen. The main application of the quinhydrone electrode is in nonaqueous solvents where reproducible results are obtained in a variety of solvents. The tetra-chloro derivative (chloranil electrode) is even more useful.

General Description

Quinhydrone/methanol treatment for the measurement of carrier lifetime in crystalline silicon substrates has been reported. Surface passivation of silicon substrates by quinhydrone/ethanol treatment has been investigated.

Description

Quinhydrone is a molecular species composed of one p-quinone(Q) and one p-hydroquinone(H2Q) held together by hydrogen bonding.

The Uses of Quinhydrone

The quinhydrone method may be used for determining PH on solid medium, such as agar, Petroff's medium, egg medium or any other solid medium when there are no secondary oxidation or reduction reactions.

Properties of Quinhydrone

Melting point:	167-172 °C (lit.)
Boiling point:	285 °C
Density	1.32
refractive index	1.4270 (estimate)
storage temp.	Store below +30°C.
solubility	4g/l
form	Crystalline Powder
Specific Gravity	0.863 (20/4℃)
color	Dark green
Water Solubility	4 g/L (20 ºC)
Sensitive	Light Sensitive
Merck	14,8058
BRN	3919222
Stability:	Stable. Incompatible with strong oxidizing agents.
CAS DataBase Reference	106-34-3(CAS DataBase Reference)
NIST Chemistry Reference	Quinhydrone(106-34-3)
EPA Substance Registry System	Quinhydrone (106-34-3)

Safety information for Quinhydrone

Signal word	Danger
Pictogram(s)	Skull and Crossbones Acute Toxicity GHS06 Environment GHS09
GHS Hazard Statements	H301:Acute toxicity,oral H400:Hazardous to the aquatic environment, acute hazard
Precautionary Statement Codes	P264:Wash hands thoroughly after handling. P264:Wash skin thouroughly after handling. P270:Do not eat, drink or smoke when using this product. P273:Avoid release to the environment. P391:Collect spillage. Hazardous to the aquatic environment P301+P310:IF SWALLOWED: Immediately call a POISON CENTER or doctor/physician. P405:Store locked up.