Names | |
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Preferred IUPAC name (4-Hydroxy-2,2,6,6-tetramethylpiperidin-1-yl)oxyl | |
Other names tempol; tanol; TMPN; 4-Oxypiperidol; nitroxyl 2; HyTEMPO | |
Identifiers | |
3D model (JSmol) | |
ChEBI | |
ChEMBL | |
ChemSpider | |
ECHA InfoCard | 100.017.056 |
PubChem CID | |
UNII | |
CompTox Dashboard (EPA) | |
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Properties | |
C9H18NO2 | |
Molar mass | 172.248 g·mol−1 |
Appearance | Orange crystals |
Melting point | 71–73 °C (160–163 °F; 344–346 K) [1] |
629.3 g/L (20 °C) | |
Hazards | |
GHS labelling: | |
[2] | |
Warning [2] | |
H302, H315, H319, H335 [2] | |
P261, P305+P351+P338 [2] | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
4-Hydroxy-TEMPO or TEMPOL, formally 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl, is a heterocyclic compound. Like the related TEMPO, it is used as a catalyst and chemical oxidant by virtue of being a stable aminoxyl radical. Its major appeal over TEMPO is that it is less expensive, being produced from triacetone amine, which is itself made via the condensation of acetone and ammonia. This makes it economically viable on an industrial scale. [3]
In biochemical research, 4-hydroxy-TEMPO has been investigated as an agent for limiting reactive oxygen species. It catalyzes the disproportionation of superoxide, facilitates hydrogen peroxide metabolism, and inhibits Fenton chemistry. [4] 4-Hydroxy-TEMPO, along with related nitroxides, are being studied for their potential antioxidant properties. [5]
On an industrial-scale 4-hydroxy-TEMPO is often present as a structural element in hindered amine light stabilizers, which are commonly used stabilizers in plastics, it is also used as a polymerisation inhibitor, particularly during the purification of styrene.
It is a promising model substance to inhibit SARS-CoV-2 RNA-dependent RNA polymerase. [6]
α-Amanitin (alpha-Amanitin) is a cyclic peptide of eight amino acids. It is possibly the most deadly of all the amatoxins, toxins found in several species of the mushroom genus Amanita, one being the death cap as well as the destroying angel, a complex of similar species, principally A. virosa and A. bisporigera. It is also found in the mushrooms Galerina marginata and Conocybe filaris. The oral LD50 of amanitin is 100 μg/kg for rats.
In chemistry, reactive oxygen species (ROS) are highly reactive chemicals formed from diatomic oxygen. Examples of ROS include peroxides, superoxide, hydroxyl radical, singlet oxygen, and alpha-oxygen.
2,2,6,6-Tetramethylpiperidine, abbreviated TMP, HTMP, or TMPH, is an organic compound of the amine class. In appearance, it is a colorless liquid and has a "fishy", amine-like odor. This amine is used in chemistry as a hindered base. Although TMP finds limited use per se, its derivatives are a mainstay of hindered amine light stabilizers.
N-Oxoammonium salts are a class of organic compounds with the formula [R1R2=O]X−. The cation [R1R2=O] is of interest for the dehydrogenation of alcohols. Oxoammonium salts are diamagnetic, whereas the nitroxide has a doublet ground state. A prominent N-oxoammonium salt is prepared by oxidation of (2,2,6,6-tetramethylpiperidin-1-yl)oxyl, commonly referred to as [TEMPO]+. A less expensive analogue is Bobbitt's salt.
In industrial chemistry, a stabilizer or stabiliser is a chemical that is used to prevent degradation.
Myricetin is a member of the flavonoid class of polyphenolic compounds, with antioxidant properties. Common dietary sources include vegetables, fruits, nuts, berries, tea, and red wine. Myricetin is structurally similar to fisetin, luteolin, and quercetin and is reported to have many of the same functions as these other members of the flavonol class of flavonoids. Reported average intake of myricetin per day varies depending on diet, but has been shown in the Netherlands to average 23 mg/day.
RNA-dependent RNA polymerase (RdRp) or RNA replicase is an enzyme that catalyzes the replication of RNA from an RNA template. Specifically, it catalyzes synthesis of the RNA strand complementary to a given RNA template. This is in contrast to typical DNA-dependent RNA polymerases, which all organisms use to catalyze the transcription of RNA from a DNA template.
Triacetonamine is an organic compound with the formula OC(CH2CMe2)2NH (where Me = CH3). It is a colorless or white solid that melts near room temperature. The compound is an intermediate in the preparation of 2,2,6,6-tetramethylpiperidine, a sterically hindered base and precursor to the reagent called TEMPO. Triacetonamine is formed by the poly-aldol condensation of acetone in the presence of ammonia and calcium chloride:
Hindered amine light stabilizers (HALS) are chemical compounds containing an amine functional group that are used as stabilizers in plastics and polymers. These compounds are typically derivatives of tetramethylpiperidine and are primarily used to protect the polymers from the effects of photo-oxidation; as opposed to other forms of polymer degradation such as ozonolysis. They are also increasingly being used as thermal stabilizers, particularly for low and moderate level of heat, however during the high temperature processing of polymers they remain less effective than traditional phenolic antioxidants.
Polymer stabilizers are chemical additives which may be added to polymeric materials, such as plastics and rubbers, to inhibit or retard their degradation. Common polymer degradation processes include oxidation, UV-damage, thermal degradation, ozonolysis, combinations thereof such as photo-oxidation, as well as reactions with catalyst residues, dyes, or impurities. All of these degrade the polymer at a chemical level, via chain scission, uncontrolled recombination and cross-linking, which adversely affects many key properties such as strength, malleability, appearance and colour.
Oxoammonium-catalyzed oxidation reactions involve the conversion of organic substrates to more highly oxidized materials through the action of an N-oxoammonium species. Nitroxides may also be used in catalytic amounts in the presence of a stoichiometric amount of a terminal oxidant. Nitroxide radical species used are either 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) or derivatives thereof.
(2,2,6,6-Tetramethylpiperidin-1-yl)oxyl or (2,2,6,6-tetramethylpiperidin-1-yl)oxidanyl, commonly known as TEMPO, is a chemical compound with the formula (CH2)3(CMe2)2NO. This heterocyclic compound is a red-orange, sublimable solid. As a stable aminoxyl radical, it has applications in chemistry and biochemistry. TEMPO is used as a radical marker, as a structural probe for biological systems in conjunction with electron spin resonance spectroscopy, as a reagent in organic synthesis, and as a mediator in controlled radical polymerization.
An organic radical battery (ORB) is a type of battery first developed in 2005. As of 2011, this type of battery was generally not available for the consumer, although their development at that time was considered to be approaching practical use. ORBs are potentially more environmentally friendly than conventional metal-based batteries, because they use organic radical polymers to provide electrical power instead of metals. ORBs are considered to be a high-power alternative to the Li-ion battery. Functional prototypes of the battery have been researched and developed by different research groups and corporations including the Japanese corporation NEC.
Deepak Thankappan Nair is an Indian Structural Biologist and a scientist at Regional Centre for Biotechnology. He is known for his studies on DNA and RNA polymerases. Deepak was a Ramanujan fellow of the Science and Engineering Research Board (2008–2013) and a recipient of the National BioScience Award for Career Development. The Council of Scientific and Industrial Research, the apex agency of the Government of India for scientific research, awarded him the Shanti Swarup Bhatnagar Prize for Science and Technology, one of the highest Indian science awards, for his contributions to biological sciences in 2017.
Aminoxyl denotes a radical functional group with general structure R2N–O•. It is commonly known as a nitroxyl radical or a nitroxide, however IUPAC discourages the use of these terms, as they erroneously suggest the presence of a nitro group. Aminoxyls are structurally related to hydroxylamines and N-oxoammonium salts, with which they can interconvert via a series of redox steps.
4-Amino-2,2,6,6-tetramethyl-4-piperidine is an organic compound with the formula H2NCH(CH2CMe2)2NH (where Me = CH3). Classified as a diamine, it is a colorless oily liquid.
Polymerisation inhibitors are chemical compounds added to monomers to prevent their auto-polymerisation. Unsaturated monomers such as acrylates, vinyl chloride, butadiene and styrene require inhibitors for both processing and safe transport and storage. Many monomers are purified industrially by distillation, which can lead to thermally initiated polymerisation. Styrene for example is distilled at temperatures above 100 °C whereupon it undergoes thermal polymerisation at a rate of ~2% per hour. This polymerisation is undesirable, as it can foul the fractionating tower, it is also typically exothermic which can lead to a runaway reaction and potential explosion if left unchecked. Once initiated polymerisation is typically radical in mechanism and as such many polymerisation inhibitors act as radical scavengers.
IDX-184 is an antiviral drug which was developed as a treatment for hepatitis C, acting as a NS5B RNA polymerase inhibitor. While it showed reasonable effectiveness in early clinical trials it did not progress past Phase IIb. However research using this drug has continued as it shows potentially useful activity against other emerging viral diseases such as Zika virus, and coronaviruses including MERS, and SARS-CoV-2.
The Stahl oxidation is a copper-catalyzed aerobic oxidation of primary and secondary alcohols to aldehydes and ketones. Known for its high selectivity and mild reaction conditions, the Stahl oxidation offers several advantages over classical alcohol oxidations.
1-Hydroxy-2,2,6,6-tetramethylpiperidine is the organic compound with the formula C5H6Me4NOH (Me = CH3). A white solid, it is classified as a hydroxylamine. The compound has attracted interest as the reduced derivative of the popular radical 2,2,6,6-tetramethylpiperidin-1-yl)oxyl ("TEMPO"). It is a mild base.