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Thiuram disulfides are a class of
Thiuram disulfides are weak oxidant. They can be reduced to dithiocarbamates. Treatment of thiuram disulfides with triphenylphosphine or
organosulfur compound
Organosulfur compounds are organic compounds that contain sulfur. They are often associated with foul odors, but many of the sweetest compounds known are organosulfur derivatives, e.g., saccharin. Nature abounds with organosulfur compounds—sulfu ...
s with the formula (R2NCSS)2. Many examples are known, but popular ones include R = Me and Et. They are disulfides obtained by oxidation of the dithiocarbamates. These compounds are used in sulfur vulcanization
Sulfur vulcanization is a chemical process for converting natural rubber or related polymers into materials of varying hardness, elasticity, and mechanical durability by heating them with sulfur or sulfur-containing compounds. Sulfur forms cros ...
of rubber as well as pesticides and drugs. They are typically white or pale yellow solids that are soluble in organic solvents.
Preparation, structure, reactions
They are prepared by the oxidation of the salts of the corresponding dithiocarbamates (e.g.sodium diethyldithiocarbamate
Sodium diethyldithiocarbamate is the organosulfur compound with the formula NaS2CN(C2H5)2. It is a pale yellow, water soluble salt.
Preparation
This salt is obtained by treating carbon disulfide with diethylamine in the presence of sodium hydrox ...
). Typical oxidants are chlorine and hydrogen peroxide:
:2 R2NCSSNa + Cl2 → (R2NCSS)2 + 2 NaCl
Thiuram disulfides react with Grignard reagents to give esters of dithiocarbamic acid, as in the preparation of methyl dimethyldithiocarbamate:
: e2NC(S)Ssub>2 + MeMgX → Me2NC(S)SMe + Me2NCS2MgX
The compounds feature planar dithiocarbamate subunits and are linked by an S−S bond of 2.00 Å. The C(S)−N bond is short (1.33 Å), indicative of multiple bonding. The dihedral angle between the two dithiocarbamate subunits approaches 90°.
Thiuram disulfides are weak oxidant. They can be reduced to dithiocarbamates. Treatment of thiuram disulfides with triphenylphosphine or cyanide
Cyanide is a naturally occurring, rapidly acting, toxic chemical that can exist in many different forms.
In chemistry, a cyanide () is a chemical compound that contains a functional group. This group, known as the cyano group, consists of a ...
salts gives the thiuram sulfide:
:(R2NCSS)2 + PPh3 → (R2NCS)2S + SPPh3
Chlorination of the above-mentioned thiuram disulfide affords the thiocarbamoyl chloride.
Applications
The tetramethyl derivative, known as thiram, is a widely used fungicide. The tetraethyl derivative, known asdisulfiram
Disulfiram is a medication used to support the treatment of chronic alcoholism by producing an acute sensitivity to ethanol (drinking alcohol). Disulfiram works by inhibiting the enzyme acetaldehyde dehydrogenase, causing many of the effects of ...
, is commonly used to treat chronic alcoholism. It produces an acute sensitivity to alcohol ingestion by blocking acetaldehyde dehydrogenase conversion of acetaldehyde
Acetaldehyde (IUPAC systematic name ethanal) is an organic chemical compound with the formula CH3 CHO, sometimes abbreviated by chemists as MeCHO (Me = methyl). It is a colorless liquid or gas, boiling near room temperature. It is one of the mos ...
leading to a higher concentration of the aldehyde in the blood producing symptoms of a severe hangover.
Safety
In 2005–06, thiuram mix was the 13th most prevalent allergen in patch tests (3.9%).References
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