Thiophosphate

Thiophosphates (or phosphorothioates, PS) are chemical compounds and anions with the general chemical formula PS4−xO3−x (x = 0, 1, 2, or 3) and related derivatives where organic groups are attached to one or more O or S. Thiophosphates feature tetrahedral phosphorus(V) centers.zinc dialkyldithiophosphate, an oil additive.Phosphorothioates are the basis for antisense therapies.Amifostine, which is used in cancer chemotherapy.Chlorpyrifos, a popular insecticide.Malathion, a popular insecticide. Thiophosphates (or phosphorothioates, PS) are chemical compounds and anions with the general chemical formula PS4−xO3−x (x = 0, 1, 2, or 3) and related derivatives where organic groups are attached to one or more O or S. Thiophosphates feature tetrahedral phosphorus(V) centers. Organothiophosphates are a subclass of organophosphorus compounds that are structurally related to the inorganic thiophosphates. Common members have formulas of the type (RO)3−xRxPS and related compounds where RO is replaced by RS. Many of these compounds are used as insecticides, some have medical applications, and some have been used as oil additives. Oligonucleotide phosphorothioates (OPS) are modified oligonucleotides where one of the oxygen atoms in the phosphate moiety is replaced by sulfur. They are the basis of antisense therapy, e.g., the drugs fomivirsen (Vitravene), oblimersen, alicaforsen, and mipomersen (Kynamro). The simplest thiophosphates have the formula 3−. These trianions are only observed at very high pH, instead they exist in protonated form with the formula (3−n)−. Monothiophosphate is the anion 3−, which has C3v symmetry. A common salt is sodium monothiophosphate (Na3PO3S). Monothiophosphate is used in research as an analogue of phosphate in biochemistry. Monothiophosphate esters are biochemical reagents used in the study of transcription, substitution interference assays. Sometimes, 'monothiophosphate' refers to esters such as (CH3O)2POS−. Dithiophosphate has the formula 3−, which has C2v symmetry. Sodium dithiophosphate, which is colorless, is the major product from the reaction of phosphorus pentasulfide with NaOH: Dithiophosphoric acid is obtained by treatment of barium dithiophosphate with sulfuric acid: Both Na3PO2S2 and especially H3PO2S2 are prone toward hydrolysis to their monothio derivatives. Trithiophosphate is the anion 3−, which has C3v symmetry. Tetrathiophosphate is the anion 3−, which has Td symmetry.