2896-70-0

Usage

Uses

Used in Electron Spin Resonance (ESR) Studies:
4-Oxo-2,2,6,6-tetramethylpiperidinooxy is used as a spin label for ESR studies, allowing researchers to monitor the production of reactive oxygen species (ROS) in biological systems.
Used in Redox Sources for Anodes in Lithium Secondary Batteries:
4-Oxo-2,2,6,6-tetramethylpiperidinooxy is used as a free-radical nitroxide spin probe, which can be utilized in the development of redox sources for anodes in lithium secondary batteries.
Used in Free-Radical Biological Studies:
In the field of biological research, 4-Oxo-2,2,6,6-tetramethylpiperidinooxy is used as a free-radical nitroxide spin probe for studying the behavior and interactions of free radicals in biological systems.
Used in Radical Spin-Trapping:
4-Oxo-2,2,6,6-tetramethylpiperidinooxy is employed as a spin trap in chemical and biological studies, helping to identify and characterize short-lived free radicals.
Used in Electron Paramagnetic Resonance (EPR) Studies:
4-Oxo-2,2,6,6-tetramethylpiperidinooxy is used in EPR studies to investigate the properties and interactions of various paramagnetic species.
Used in Polymer Chemistry and Synthesis Applications:
4-Oxo-2,2,6,6-tetramethylpiperidinooxy is utilized as a polarizing agent in dynamic nuclear polarization NMR spectroscopy, which is essential in polymer chemistry and synthesis applications for understanding the structure and dynamics of polymers.
Used in Pharmaceutical Applications:
TEMPONE and other nitroxyl radicals have demonstrated the ability to reduce mean arterial pressure in spontaneously hypertensive rats when administered intravenously, indicating potential pharmaceutical applications in the treatment of hypertension.

Flammability and Explosibility

Nonflammable

InChI:InChI=1/C9H16NO2/c1-8(2)5-7(11)6-9(3,4)10(8)12/h5-6H2,1-4H3

Upstream product

• 826-36-8 2,2,6,6-Tetramethyl-4-piperidone 
• 33973-59-0 2,2,6,6-tetramethylpiperidin-4-one hydrochloride 
• 22963-71-9 1-hydroxy-4-oxo-2,2,6,6-tetramethylpiperidine hydrochloride 
• 137003-52-2 <15N>-2,2,6,6-tetramethyl-4-piperidone 
• 2403-88-5 4-hydroxy-2,2,6,6-tetramethylpiperidine 
• 95407-69-5 4-methoxy-2,2,6,6-tetramethylpiperidin-1-oxyl radical 
• 37149-18-1 1-oxyl-4-carboxyl-2,2,6,6-tetramethylpiperidine 
• 45985-24-8 TEMPOL 
• 32889-28-4 2,2,6,6-Tetramethyl-4-oxo-1-hydroxypiperidinium-perchlorat 
• 122586-81-6 2,2,6,6-tetramethyl-1-(1-phenylethoxy)-4-piperidinone 
• 42391-54-8 2-<4-chlorophenyl>-4,6-diphenylverdazyl 
• 122-66-7 diphenyl hydrazine 
• 2564-83-2 2,2,6,6-Tetramethyl-1-piperidinyloxy free radical 
• 3637-11-4 1-hydroxy-2,2,6,6-tetramethyl-piperidin-4-one 

Downstream Products

• 128954-25-6 3-bromo-2,2,5,5-tetramethyl-Δ³-pyrrolin-1-oxyl 
• 78033-68-8 3,4-dibromo-2,2,5,5-tetramethyl-Δ³-pyrrolin-1-oxyl 
• 78033-70-2 3-bromo-4-methoxycarbonyl-2,2,5,5-tetramethyl-Δ³-pyrrolin-1-oxyl 
• 3637-11-4 1-hydroxy-2,2,6,6-tetramethyl-piperidin-4-one 
• 35822-90-3 benzoyl-tert-butylnitroxyl radical 
• 73312-30-8 C₁₃H₁₈NO₂ 
• 53544-99-3 p-Nitrobenzoyl-tert-butylnitroxid 
• 53545-01-0 p-Methoxybenzoyl-tert.-butyl-nitroxid 
• 97871-97-1 2-(p-tolyl)-4,6-diphenyl-3,4-dihydro-1,2,4,5-tetrazin-1(2H)-yl 
• 42391-54-8 2-<4-chlorophenyl>-4,6-diphenylverdazyl 
• 42450-45-3 2-(4-methoxyphenyl)-4,6-diphenyl-3,4-dihydro-1,2,4,5-tetrazin-1(2H)-yl 
• 29872-18-2 2-(4-nitrophenyl)-4,6-phenyl-3,4-dihydro-1,2,4,5-tetrazin-1(2H)-yl 
• 99910-02-8 C₂₁H₁₈N₅O₃ 
• 99910-01-7 2-(p-methoxyphenyl)-4-phenyl-6-(p-nitrophenyl)-3,4-dihydro-2H-sym-tetrazin-1-yl 

Relevant academic research and scientific papers

Effect of Sterical Shielding on the Redox Properties of Imidazoline and Imidazolidine Nitroxides

The oxidant properties of the series of 2,2,5,5-tetraalkyl imidazoline and imidazolidine nitroxides were investigated. An increase in the number of bulky alkyl substituents leads to a decrease in the rate of reduction with ascorbate, which makes the electrochemical reduction potential more negative and shifts the equilibrium in the mixture of nitroxide and reference hydroxylamine (3-carboxy-1-hydroxy-2,2,5,5-tetramethylpyrrolidine-1-oxyl-1-15N) toward the starting compounds. The effect of structural factors on these reactions was analyzed by means of multiple regression using the Fujita steric constant Es and the inductive Hammett constant σI. Satisfactory statistical outputs were obtained in all of the biparameter correlations, denoting that the oxidant properties of the nitroxides are determined by steric and electronic effects of the substituents. The data imply that bulky substituents can stabilize nitroxide and/or destabilize hydroxylamine.

Mussel-inspired preparation of C60 nanoparticles as photo-driven DNA cleavage reagents

Designing and constructing favorable water-dispersible fullerenes and their derivatives are of huge importance for biological applications addressing DNA-cleavage and photodynamic therapy (PDT). In the present work, a mild, green and facile synthetic approach for the preparation of C60 nanoparticles was developed for the first time via the combination of mussel-inspired chemistry and the Michael addition reaction. The resultant C60-PDA-PEI nanoparticles were characterized by transmission electron microscopy (TEM), dynamic laser scattering (DLS), Fourier-transform infrared spectroscopy (FT-IR), Raman spectra, X-ray photoelectron spectra (XPS) and thermogravimetric analysis (TGA), demonstrating that the above two-step strategy allows easy access to the preparation of highly water-dispersible fullerene derivatives. Benefiting from their unique nanostructure, the versatile C60-PDA-PEI nanoparticles display a uniform hydrodynamic size of 160 nm in water and efficient 1O2 generation under irradiation. Furthermore, the good ability of cleaving DNA under visible light at a mass concentration of 62.5 ng μL-1 gives them high potential as PDT agents. The universal approach described in this work is capable of introducing many other functional molecules onto PDA-modified fullerenes, thus extending the possible applications of fullerene-based species in many fields of biotechnology and pharmaceutical chemistry.

Kinetic analysis of nitroxide radical formation under oxygenated photolysis: Toward quantitative singlet oxygen topology

Reaction kinetics for two sterically hindered secondary amines with singlet oxygen have been studied in detail. A water soluble porphyrin sensitizer, 5,10,15,20-tetrakis-(4-sulfunatophenyl)-21,23H-porphyrin (TPPS), was irradiated in oxygenated aqueous solutions containing either 2,2,6,6-tetramethylpiperidin-4-one (TMPD) or 4-[N,N,N-trimethyl-ammonium]-2,2,6,6-tetramethylpiperidinyl chloride (N-TMPCl). The resulting sensitization reaction produced singlet oxygen in high yield, ultimately leading to the formation of the corresponding nitroxide free radicals (R2NO) which were detected using steady-state electron paramagnetic resonance (EPR) spectroscopy. Careful actinometry and EPR calibration curves, coupled with a detailed kinetic analysis, led to a simple and compact expression relating the nitroxide quantum yield ΦR2NO (from the doubly-integrated EPR signal intensity) to the initial amine concentration [R2NH]i. With all other parameters held constant, a plot of ΦR2NOvs. [R2NH]i gave a straight line with a slope proportional to the rate constant for nitroxide formation, kR2NO. This establishment of a rigorous quantitative relationship between the EPR signal and the rate constant provides a mechanism for quantifying singlet oxygen production as a function of its topology in heterogeneous media. Implications for in vivo assessment of singlet oxygen topology are briefly discussed. This journal is

Novel 6-formylpterin derivatives: Chemical synthesis and O2 to ROS conversion activities

6-Formylpterin (6FP) has been demonstrated to have strong neuroprotective effects against transient ischemia-reperfusion injury in gerbils. Also it has been shown that in rats, 6FP protected retinal neurons even when it was administered after the ischemic insult. Since there is a significant need for such a compound that effectively suppresses the events caused by the lack of oxygen supply, 6FP has attracted further investigation. Unfortunately, however, 6FP is hardly soluble in water at neutral pH and in organic solvents because of its self-assembling ability. Although a several mM solution of 6FP is available in alkaline water, it is unstable. In the present study, a novel chemical derivatization of 6FP has been developed which maintains the formyl group on the 6-position of 6FP, which is essential for the physiological activities of 6FP, and increases solubility in water and organic solvents. In the method, the 2- and 3-positions of 6FP were modified by a three component coupling reaction: 6FP was subjected to the reaction with acid chloride and N,N-dimethylformamide. The derivatives synthesized here, 2-(N,N-dimethylaminomethyleneamino)-6-formyl-3- pivaloylpteridine-4-one 1, 2-(N,N-dimethylaminomethyleneamino)-6-formyl-3- isobutyrylpteridine-4-one 2, and 2-(N,N-dimethylaminomethyleneamino)-6-formyl-3- o-toluoylpteridine-4-one 3, showed high solubility in water (1.0-5.6 mM) and organic solvents. The O2 conversion property has also been determined for the derivative 1. Using an oxygen electrode, it has been found that O 2 is consumed in the presence of 1 and NADH at around pH 7.4 and that the rate of O2 consumption is enhanced by UV-A irradiation. Electron paramagnetic resonance (EPR) analysis coupled with DMPO spin trapping has also revealed that in the presence of NADH, 1 converts O2 to O 2-, which is further reduced to OH. By UV-A illumination in the analogous systems, 1O2 formation was observed. These results are similar to those reported previously for 6FP. The Royal Society of Chemistry 2006.

Oxidation of 4-substituted TEMPO derivatives reveals modifications at the 1- and 4-positions

Potenital pathways for the deactivation of hindered amine light stabilisers (HALS) have been investigated by observing reactions of model compounds - based on 4-substituted derivatives of 2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO) - with hydroxyl radicals. In these reactions, dilute aqueous suspensions of photocatalytic nanoparticulate titanium dioxide were irradiated with UV light in the presence of water-soluble TEMPO derivatives. Electron spin resonance (ESR) and electrospray ionisation mass-spectrometry (ESI-MS) data were acquired to provide complementary structural elucidation of the odd- and even-electron products of these reactions and both techniques show evidence for the formation of 4-oxo-TEMPO (TEMPONE). TEMPONE formation from the 4-substituted TEMPO compounds is proposed to be initiated by hydrogen abstraction at the 4-position by hydroxyl radical. High-level ab initio calculations reveal a thermodynamic preference for abstraction of this hydrogen but computed activation barriers indicate that, although viable, it is less favoured than hydrogen abstraction from elsewhere on the TEMPO scaffold. If a radical is formed at the 4-position however, calculations elucidate two reaction pathways leading to TEMPONE following combination with either a second hydroxyl radical or dioxygen. An alternate mechanism for conversion of TEMPOL to TEMPONE via an alkoxyl radical intermediate is also considered and found to be competitive with the other pathways. ESI-MS analysis also shows an increased abundance of analogous 4-substituted piperidines during the course of irradiation, suggesting competitive modification at the 1-position to produce a secondary amine. This modification is confirmed by characteristic fragmentation patterns of the ionised piperidines obtained by tandem mass spectrometry. The conclusions describe how reaction at the 4-position could be responsible for the gradual depletion of HALS in pigmented surface coatings and secondly, that modification at nitrogen to form the corresponding secondary amine species may play a greater role in the stabilisation mechanisms of HALS than previously considered. The Royal Society of Chemistry 2011.

Waste-derived bioorganic substances for light-induced generation of reactive oxygenated species

Urban waste-derived bioorganic substances (UW-BOS) have shown promise as chemical auxiliaries for a number of technological applications in the chemical industry and in environmental remediation. In this study, the application of these substances in the photodegradation of organic pollutants is addressed. The experimental work is specifically focused on the photolysis mechanism promoted by AC8, a UW-BOS isolated from a 2:1 w/w mixture of food and green residues, composted for 110 days, using 4-chlorophenol (4-CP) as probe molecule. The production of OH and the 1O2 is monitored by EPR spectroscopy. The correlation between radical species evolution and photodegradation of 4-CP is investigated. The effect of 1O 2 and OH scavengers on the 4-CP degradation process is also checked. The results suggest that the role of these species in the photodegradation of 4-CP depends on AC8 concentration. AC8 is thereby proven to be a photosensitizer for applications in environmental remediation. The results on AC8 further support the use of urban bio-waste as a versatile source of chemical auxiliaries of biological origin for use in diversified applications. An offer you can't refuse: A bioorganic substance isolated from a composted urban refuse (AC8) is applied as sensitizer in the photodegradation of 4-chlorophenol. Production of OH and 1O2 species is monitored by EPR spectroscopy and the data suggest that the role played by these species in the photodegradation process is strictly related to AC8 concentration. AC8 is thereby proven to be a photosensitizer for applications in environmental remediation.

A new trick (hydroxyl radical generation) of an old vitamin (B2) for near-infrared-triggered photodynamic therapy

The photosensitizer has been supposed to be the key component in photodynamic therapy (PDT). Natural products and their intricate molecular frameworks are often used as starting points for drug discovery. Riboflavin (RF), also known as vitamin B2, has a unique conjugate structure of an isoalloxazine ring, and is a potential photosensitizer for use in the PDT of cancers. In this study, a novel near-infrared (NIR) mediated nanocomposite for PDT is presented, using this old vitamin (RF) as a PDT photosensitizer, integrated with the upconversion nanotechnology. Mesoporous silica coated sodium yttrium fluoride:ytterbium/thulium (NaYF4:Yb/Tm) nanoparticles were fabricated and used as drug carriers and photo-transducers. Chemical modification of RF was performed to obtain a photostable photosensitizer, 2′,3′,4′,5′-tetraacetylriboflavin (RTA). There is a good overlap between the fluorescence emission of NaYF4:Yb/Tm nanoparticles and the UV-visible absorption of RTA. The RTA molecules were incorporated into the mesoporous silica shell and the fluorescent emission from the NaYF4:Yb/Tm nanoparticles can be absorbed by RTA molecules under NIR irradiation. NIR-initiated reactive oxygen species generation was validated using electron paramagnetic resonance (EPR) spectroscopy combined with spin trapping. The results from the in vitro cell test show that this nanocomposite has good photodynamic efficacy. All the chemicals involved in this process are non-toxic, environmentally benign, and easily available. Thus, this nanocomposite has great potential in PDT applications.

Singlet oxygen generation properties of an inclusion complex of cyclic free-base porphyrin dimer and fullerene C60

To gain insight into the singlet oxygen (1O2) generation properties of supramolecular complexes of cyclic free-base porphyrin dimer with fullerene C60, we evaluated the 1O2 quantum yield (ΦΔ) and rate constant (Kobs) of 1O2 generation for a cyclic free-base porphyrin dimer (CPD) linked by butadiyne bearing four 4-pyridyl groups and its inclusion complex (C60?CPD) with C60. We demonstrate that CPD and C60?CPD possess the ability to generate 1O2 under visible light irradiation. Moreover, it was found that the ΦΔ value of C60?CPD is lower than that of CPD. Based on the kinetic and thermodynamic consideration concerning the electron transfer processes between the porphyrin dimer and C60, this work revealed that the lower ΦΔ value of the C60 inclusion complex would be attributed to the formation of the charge-separated state c60·?-CPD·+, leading to a low intersystem crossing (ISC) efficiency for the formation of the triplet excited state 3(CPD)*.

Method for preparing hindered amine nitroxide free radical compound by alkaline heterogeneous catalysis system

The method comprises the following steps: dissolving a hindered amine compound in an organic solvent; adjusting pH by a carbonate aqueous solution; reacting with an aqueous hydrogen peroxide solution; and generating a hindered amine nitroxide free radical compound (IV). (V) Or (VI). The method is high in universality, and the hindered amine nitroxide free radical compound with various structures is prepared. The method is high in catalytic activity, short in reaction time, high in yield, simple in preparation process and convenient to operate; a high-purity target product can be obtained through simple phase separation, drying and concentration in the post-treatment process; meanwhile, the aqueous solution system and ethyl acetate can be recycled. Small by-products.

Spin-labeled naphthalimide oxygen-containing compound and application thereof

The invention belongs to the technical field of medical drugs, and relates to a spin-labeled naphthalimide compound containing an oxygen substituent and an application thereof, in particular to a stable nitroxide free radical labeled naphthalimide compound containing an oxygen substituent and an application thereof in preparation of anti-tumor drugs. According to the spin-labeled naphthalimide oxygen-containing compound and the application thereof, a stable nitroxide free radical is introduced into an oxygen-containing substituent naphthalimide parent to obtain the naphthalimide compound shown in the general formula I and pharmaceutically acceptable salt thereof, and the compound has good anti-tumor activity, shows lower toxicity to normal cells than a naphthalimide analogue containing a nitrogen substituent, and has very good development and application prospects.