Thiocarbonic acid is an
inorganic
In chemistry, an inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds, that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as ''inorganic chemis ...
acid with the
chemical formula
In chemistry, a chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, ...
(or ). It is an analog of
carbonic acid (or ), in which all
oxygen
Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as we ...
atoms are replaced with
sulfur
Sulfur (or sulphur in British English) is a chemical element with the symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms form cyclic octatomic molecules with a chemical formul ...
atoms. It is an unstable
hydrophobic
In chemistry, hydrophobicity is the physical property of a molecule that is seemingly repelled from a mass of water (known as a hydrophobe). In contrast, hydrophiles are attracted to water.
Hydrophobic molecules tend to be nonpolar and, ...
red oily liquid.
It is often referred to as trithiocarbonic acid so as to differentiate it from other carbonic acids containing sulfur, such as monothiocarbonic ''O'',''O''-acid , monothiocarbonic ''O'',''S''-acid , dithiocarbonic ''O'',''S''-acid and dithiocarbonic ''S'',''S''-acid (see
thiocarbonate Thiocarbonate describes a family of anions with the general chemical formula (''x'' = 0, 1, or 2):
*for ''x'' = 2 it is monothiocarbonate ion
*for ''x'' = 1 it is dithiocarbonate ion
*for ''x'' = 0 it is trithiocarbonate ion
Like the carbonat ...
s).
Discovery and synthesis
It was first reported in brief by
Zeise in 1824 and later in more detail by
Berzelius in 1826, in both cases it was produced by the action of
carbon disulfide
Carbon disulfide (also spelled as carbon disulphide) is a neurotoxic, colorless, volatile liquid with the formula and structure . The compound is used frequently as a building block in organic chemistry as well as an industrial and chemical ...
on a
hydrosulfide
Bisulfide (or bisulphide in British English) is an inorganic anion with the chemical formula HS− (also written as SH−). It contributes no color to bisulfide salts, and its salts may have a distinctive putrid smell. It is a strong base. Bi ...
salt (e.g.
potassium hydrosulfide
Potassium hydrosulfide is the inorganic compound with the formula KSH. This colourless salt consists of the cation and the bisulfide anion . It is the product of the half-neutralization of hydrogen sulfide with potassium hydroxide. The compound is ...
).
:
Treatment with acids liberates the thiocarbonic acid as a red oil
:
Both the acid and many of its salts are unstable and decompose via the release of carbon disulfide, particularly upon heating:
:
An improved synthesis involves addition of barium trithiocarbonate to hydrochloric acid at 0 °C. This method provided samples with which many measurement have been made.
[
Despite its lability, crystals of thiocarbonic acid have been examined by ]X-ray crystallography
X-ray crystallography is the experimental science determining the atomic and molecular structure of a crystal, in which the crystalline structure causes a beam of incident X-rays to diffract into many specific directions. By measuring the angle ...
, which confirms the anticipated molecular structure of a trigonal–planar central carbon atom. The C-S bond lengths range from 1.69 to 1.77 Å.
Reactions and derivatives
Thiocarbonic acid is acidic
In computer science, ACID ( atomicity, consistency, isolation, durability) is a set of properties of database transactions intended to guarantee data validity despite errors, power failures, and other mishaps. In the context of databases, a s ...
, with the first p''K''a being around 2. The second p''K''a is near 7. It dissolves , but does not react with it.[
Salts and esters of trithiocarbonic acid are called trithiocarbonates, and they are sometimes called thioxanthates.
Thiocarbonic acid reacts with ]bifunctional
In organic chemistry, when a single organic molecule has two different functional groups, it is called a bifunctional molecule . A bifunctional molecule has the properties of two different types of functional groups, such as an alcohol (), amide ( ...
reagents
In chemistry, a reagent ( ) or analytical reagent is a substance or compound added to a system to cause a chemical reaction, or test if one occurs. The terms ''reactant'' and ''reagent'' are often used interchangeably, but reactant specifies a ...
to give rings
Ring may refer to:
* Ring (jewellery), a round band, usually made of metal, worn as ornamental jewelry
* To make a sound with a bell, and the sound made by a bell
:(hence) to initiate a telephone connection
Arts, entertainment and media Film and ...
. 1,2-Dichloroethane
The chemical compound 1,2-dichloroethane, commonly known as ethylene dichloride (EDC), is a chlorinated hydrocarbon. It is a colourless liquid with a chloroform-like odour. The most common use of 1,2-dichloroethane is in the production of vin ...
gives ethylene trithiocarbonate
Ethylene trithiocarbonate is an organosulfur compound with the formula . This yellow solid is prepared by alkylation of trithiocarbonate with 1,2-dibromoethane
1,2-Dibromoethane, also known as ethylene dibromide (EDB), is an organobromine compound ...
(). Oxalyl chloride
Oxalyl chloride is an organic chemical compound with the formula (COCl)2. This colorless, sharp-smelling liquid, the diacyl chloride of oxalic acid, is a useful reagent in organic synthesis.
Preparation
Oxalyl chloride was first prepared in 189 ...
gives oxalyl trithiocarbonate
The oxalyl cation, also known as ''oxalic'', has the chemical formula 2O2sup>2+. It is the cation derived from oxalic acid.
Chemical compounds containing the oxalyl cation include:
Related compounds/ions
*Oxalic acid
Oxalic acid is an org ...
().
Applications
Thiocarbonic acid currently has no significant applications. Its esters find use in RAFT polymerization.
References
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Hydrogen compounds
Sulfur(−II) compounds
Inorganic carbon compounds