Basic Hydrogen Peroxide Research Articles

Efficient pulsed chemical oxygen-iodine laser with instantaneous generation of atomic iodine by volumetric discharge

A pulsed chemical oxygen-iodine laser (COIL) using atomic iodine generated by volumetric discharge of CH3I is developed and tested. COIL with a gain length of 60 cm is energized by a square pipe-array jet singlet oxygen generator with basic hydrogen peroxide pumping circulations and operated at subsonic gas flow. Maximum output energy of 4.3 J, pulse duration of 50 μs, specific energy extraction from the active medium of 2.0 J/L, and the maximum chemical efficiency of 12.5% are achieved at a chlorine flow rate of 55 mmole/s.

Chemiluminescent reductive acridinium triggering (CRAT)—mechanism and applications

Acridinium esters traditionally are triggered using basic hydrogen peroxide. By serendipity, we have found that acridinium esters can also be triggered with emission of chemiluminescence by reductive triggering, e.g., by zinc metal or reduced forms of ferric and cupric salts. Furthermore, organic reducing compounds like dithiothreitol, tricarboxyethylphosphine or glutathione could be used in combination with organic oxidants like quinones or inorganic ferric or cupric salts. Mechanisms are proposed which involve the intermediacy of superoxide. Two forms of reactive oxygen species (i.e., hydrogen peroxide and superoxide) could be discriminated based on differences in kinetics. Some applications (improved detection of acridinium ester, use of acridinium ester as redox probes) are discussed.

Formation and Reactivity of a Biomimetic Hydroperoxocopper(II) Cryptate

AbstractCopper(II)‐hydroperoxo species are proposed as key intermediates in the catalytic cycles of copper‐monooxygenase enzymes that perform C–H bond hydroxylation. Herein we report on the oxidation chemistry of a copper(II) complex with a coordinating cryptand based on a peralkylated tetradentate tris(2‐aminoethyl)amine (tren) moiety. X‐ray crystallography of the copper(II) acetate complex of this cryptand revealed that the copper(II) ion is in a square‐pyramidal environment, with the cryptand acting only as a tridentate ligand. This geometry is conserved in solution and likely results from restraints imposed by the semi‐rigid cryptand. Reaction of this complex with basic hydrogen peroxide in methanol led to the decomposition of the complex with an oxygen‐atom transfer to the ligand, as evidenced by mass spectrometry analysis after reaction and demetallation. Low‐temperature stopped‐flow experiments (down to –90 °C) support the formation of a copper(II)‐hydroperoxo intermediate, CuOOH, before ligand oxygenation occurs. It is proposed that this intermediate performs the oxygen‐atom transfer to a weak benzylic C–H bond of the cryptand, thereby mimicking the behavior of dopamine‐β‐hydroxylase.

Liquid-liquid reaction of hydrogen peroxide and sodium hypochlorite for the production of singlet oxygen in a centrifugal flow singlet oxygen generator

An attempt is made to produce gas-phase singlet oxygen O2(a1Δg) in a liquid-liquid reaction between acidic hydrogen peroxide (AHP) and sodium hypochlorite (NaOCl). The attempt arises from the fact that basic hydrogen peroxide (BHP) has long been the prime source for producing singlet delta oxygen through its reaction with chlorine. However, BHP suffers from the defect of being unstable during storage. Exploratory experiments were performed in a centrifugal flow singlet oxygen generator (CF-SOG) with two streams of solutions, AHP and NaOCl, mixed in a slit nozzle and then injected into the arc-shaped concavity in the CF-SOG to form a rotating liquid flow with a remarkable centrifugal force. With the help of this centrifugal force, the product of the O2(1Δ) reaction was quickly separated from the liquid phase. The gas-phase O2(1Δ) was detected via the spectrum of O2(1Δ) cooperative dimolecular emission with a CCD spectrograph. Experimental results show that it is feasible to produce gas-phase O2(1Δ) from the AHP + NaOCl reaction, and the stronger the acidity, the more efficient the O2(1Δ) production. However, since in the AHP + NaOCl reaction, Cl2 unavoidably appears as a byproduct, its catalytic action on the decomposition of H2O2 into ground-state O2 remains a major obstacle to utilising the AHP + NaOCl reaction in producing gas-phase O2(1Δ). Qualitative interpretation shows that the AHP + NaOCl reaction is virtually the reaction of interaction of molecular H2O2 with molecular HOCl, its mechanism being analogous to that of reaction of BHP with Cl2, where HOOCl is the key intermediate. It is difficult to form the intermediate HOOCl via the H2O2 + NaOCl reaction in a basic medium, thus gas-phase O2(1Δ) cannot be obtained in appreciable quantities.

ChemInform Abstract: Mild Oxidative Conversion of Nitroalkanes into Carbonyl Compounds in Ionic Liquids.

AbstractOxidation of nitro‐derivatives in ionic liquids using basic hydrogen peroxide or sodium perborate provides a mild and efficient alternative to the traditional Nef reaction.

ChemInform Abstract: Facile One‐Pot Conversion of Aldehydes into Amides.

A facile one-pot synthesis of amides from aldehydes has been developed. This tandem process involves the formation of a nitrile intermediate obtained from the reaction of an aldehyde with hydroxylamine hydrochloride in dimethylsulfoxide at 100°C and the subsequent treatment of the nitrile with basic hydrogen peroxide. The resulting amide products were produced in good yields (67–95%) and purity (>95%).

Mild Oxidative Conversion of Nitroalkanes into Carbonyl Compounds in Ionic Liquids

Basic hydrogen peroxide and sodium perborate were found to be cheap and efficient alternatives for the conversion of primary and secondary nitro to carbonyl compounds (Nef reaction) in ionic liquids.

Facile One-Pot Conversion of Aldehydes into Amides

A facile one-pot synthesis of amides from aldehydes has been developed. This tandem process involves the formation of a nitrile intermediate obtained from the reaction of an aldehyde with hydroxylamine hydrochloride in dimethylsulfoxide at 100°C and the subsequent treatment of the nitrile with basic hydrogen peroxide. The resulting amide products were produced in good yields (67–95%) and purity (>95%).

Spray generator of singlet oxygen for a chemical oxygen-iodine laser

A spray type of singlet oxygen generator for driving the Chemical Oxygen-Iodine Laser was developed. Singlet oxygen, O2(1Δg), is generated by a fast reaction of chlorine with basic hydrogen peroxide solution in the form of a dense spray. A mathematical model of this reaction system showed that O2(1Δg) can be generated in this system with a high yield (0.70–0.80), high utilization of chlorine (0.75–0.95), and effective utilization of liquid (0.36–0.54) at very high generator pressures (35–75 kPa). Experimental studies of this reaction system without an efficient separation of liquid proved an efficient O2(1Δg) production characterized by a rather high product of chlorine utilization and O2(1Δg) yield (0.4–0.9) at very high generator pressures (30–80 kPa). This pressure is much higher than the operation pressure used in other generators, which should be beneficial for a pressure recovery system of the COIL. These results provided the basis for designing a centrifugal spray generator with an efficient separation of liquid from the gas flow, which is the subject of the following paper.

Research on Uniform-Droplet Singlet-Oxygen Generator

The formation of a uniform droplet is the key in a uniform-droplet singlet-oxygen generator (SOG). This paper is mainly on the condition of uniform droplet formation. Factors in uniform-droplet formation, such as basic hydrogen peroxide (BHP) liquid velocity, disturbance frequency, and the pressure distribution in the fluid infusion cavity, were analyzed and optimized in order to improve the performance of the uniform-droplet singlet-oxygen generator. The chlorine utilization, O2(1Δ) yield, H2O concentration, and laser power were measured. The output concentration of O2(1Δ) was as high as 2.94 ×1017/cm3. The maximum power density through the nozzle was 121.3 W/cm2.

Design of a silicon‐based microscale trickle‐bed system for singlet‐oxygen production

AbstractDesign methodology and flow characterization of a miniaturized trickle‐bed system for singlet‐oxygen production via exothermic reaction of chlorine gas and basic hydrogen peroxide aqueous solution are reported. Miniaturized singlet oxygen production is accomplished by integration of several components developed for microsystems (uniform phase distributors, integrated on‐chip cooling, and capillary‐based phase separation) within a single device. Macroscale design equations for pressure‐drop and heat‐transfer rates are verified experimentally in the miniature trickle‐bed reactor. Flow regime data from the present study are summarized with previous reports in microdevices and compared to conventional multiphase flow maps; these maps are found to be incapable of accurately predicting the flow regime trends within the miniaturized trickle‐bed system. Operation of the silicon‐based miniaturized trickle‐bed reactor achieved estimated singlet‐oxygen yields of 78%, comparing well with the reactor model predictions. © 2008 American Institute of Chemical Engineers AIChE J, 2008

Experimental and Theoretical Study of Centrifugal Flow Singlet Oxygen Generator

We designed and realized a novel centrifugal flow singlet oxygen generator (CFSOG) that was originally proposed by Emanuel [Proc. SPIE 5448 (2004) 233]. In this device, singlet oxygen O2(1Δ) is generated by the reaction of gaseous Cl2 with aqueous basic hydrogen peroxide (BHP) that flows rapidly along an arc-shaped concave to form a rotating liquid layer, so that the nascent O2(1Δ) generated in the liquid phase will be separated from it quickly to suppress the collision quenching loss of O2(1Δ) with the help of the enormous centrifugal force produced by the rotating fluid. Our preliminary experiment shows that, because the specific reactive surface area of this novel singlet oxygen generator (SOG) is much larger than that of the jet-type SOG normally used in current chemical oxygen–iodine laser (COIL), enhanced performance of O2(1Δ) yield ∼60%, O2(1Δ) partial pressure ∼31 Torr, and an extremely high chlorine utilization within 96–98% have been realized.

Kinetics of Selective Formation of Ibuprofenamide by Phase Transfer Catalyzed Oxidation of 2-(4-Isobutylphenyl)propionitrile with Basic Hydrogen Peroxide

Ibuprofenamide (benzeneacetamide-α-methyl-4-(2-methylpropyl)) is an ibuprofen analogue having anti-inflammatory activity itself and a precursor of many N-derivatives, all of which have good anti-inflammatory activities. The conventional process to prepare this amide is by the conversion of ibuprofen to acid chloride by thionyl chloride followed by ammonolysis or careful hydrolysis of the nitrile with H2SO4/CH3COOH mixture. In this paper, the preparation of ibuprofenamide was achieved by the hydrolysis of 2-(4-isobutylphenyl)propionitrile with basic hydrogen peroxide under liquid−liquid phase transfer catalysis, under safe conditions with high conversion and selectivity. A systematic study was conducted to study the effects of various parameters such as different phase transfer catalysts, catalyst loading, substrate loading, and temperature on the conversion and rates of reaction. A kinetic model has been developed and validated against experimental data. With the 2-(4-isobutylphenyl)propionitrile to hydro...

O2(1Δ) Quenching Mechanism in Cl2/Basic Hydrogen Peroxide(Basic Deuterium Peroxide) Gas/Liquid Reaction and the Determination of O2(1Δ)/BHP(BDP) Interface Free Energy

In a jet-type singlet oxygen generator, we have studied the generation of O2(1Δ) via the reaction of chlorine gas with aqueous basic hydrogen peroxide (BHP) and with basic deuterium peroxide (BDP)....

Efficient Amide-Directed Catalytic Asymmetric Hydroboration

A series of acyclic beta,gamma-unsaturated amides are shown to undergo highly regio- (>95%) and enantioselective (93-99% ee) rhodium-catalyzed hydroboration with pinacolborane (PinBH) using simple chiral monophosphite or phosphoramidite ligands in combination with Rh(nbd)2BF4. The most effective ligands identified are phosphoramidite 4, derived from BINOL and N-methylaniline, and phosphite 5c, prepared from the (4'-tert-butyl)phenyl TADDOL analogue and phenol. For example, (E)-3-hexenoic acid phenylamide ((E)-1) undergoes rhodium-catalyzed hydroboration with PinBH (0.5 mol % Rh(nbd)2BF4, 1.1 mol % BINOL-derived phosphoramidite 4, THF, 40 degrees C, 2 h) affording an intermediate boronate ester which after oxidation with basic hydrogen peroxide gives the beta-hydroxy amide, (S)-3-hydroxyhexanoic acid phenylamide ((S)-3), in good yield (80%) and high enantiomeric purity (99% ee). Isomeric disubstituted (E)- and (Z)-alkenes give nearly identical results, and a trisubstituted alkene substrate is also shown to undergo efficient hydroboration (97% ee). Moderate catalyst loading (0.5 mol %) and reaction temperatures in 25-40 degrees C range are generally effective. N-Phenyl amides are generally more efficient than the corresponding N-benzyl or N,N-dibenzyl analogues. Pinacolborane is found to be more efficient than catecholborane.

Preliminary study of a centrifugal-flow singlet oxygen generator

By using the concept of a high-pressure, gravity-independent singlet oxygen generator (SOG) proposed by Emanuel and based on the principle that a rotating fluid is capable of producing an enormous centrifugal force, a novel-type centrifugal-flow singlet oxygen generator (CFSOG) was designed and constructed. In this device, O2(1Δ) was generated in the reaction of gaseous Cl2 with a rotating basic hydrogen peroxide (BHP) liquid flow and then was removed from the BHP liquid phase by the centrifugal force. Meanwhile, the microdroplets formed during the Cl2+BHP reaction were removed from the O2(1Δ) gas flow by the centrifugal force produced by the high-speed flow along an arc-shaped channel. Preliminary investigations showed that, because the specific reactive surface area of this SOG was noticeably larger than that of the jet-SOG normally used in current chemical oxygen–iodine lasers (COILs), the O2(1Δ) yield of ∼60%, the O2(1Δ) partial pressure as high as 31 Torr, and chlorine utilisation higher than 96% were realised. Moreover, steady operation was obtained.

Multikilowatt chemical oxygen-iodine laser with chemical generation of molecular iodine

A multikilowatt chemical oxygen-iodine laser (COIL) using molecular iodine generated chemically as the iodine source was developed and tested. The COIL, with a gain length of 26.5cm, was energized by a square pipe-array jet singlet oxygen generator (JSOG), with a nozzle bank having a designed Mach number of 2.5. The JSOG, operating without a primary buffer gas, has a much better operation stability during basic hydrogen peroxide pumping circulations. Iodine injectors/nozzles made of polyimide were used. An output power of 7.8kW and a chemical efficiency of 24.5% were achieved with a chlorine flow rate of 353mmole∕s.

Singlet oxygen generator based on the reaction of chlorine with filament-guided jets of basic hydrogen peroxide

The chlorine utilization efficiency and singlet oxygen concentration are determined as functions of the chlorine flow rate, the base concentration, and the flow rate and temperature of basic hydrogen peroxide in a singlet oxygen generator based on the reaction of chlorine with filament-guided descending basic hydrogen peroxide jets. The effluent gas, without aerosol entrainment, contains about 10% residual chlorine and more than 60% singlet oxygen.

An efficient synthesis of diquinane-based bis-γ-lactones

An efficient stereoselective synthesis of both the diastereomers of diquinane-based conformationally constrained symmetric bis-γ-lactones starting from tricyclic derivative 9 is reported. The key step involves the intramolecular ring opening of an epoxide by the in situ formed hydrate of a diketone leading to the tetracyclic hemiacetal 10, which directly leads to the exo-hydroxy bis-γ-lactone derivatives 2 and 4 under basic hydrogen peroxide cleavage conditions. Conversion to the endo-hydroxy bis-γ-lactone derivatives 1 and 3 was accomplished through lithium hydroxide mediated SN2 displacements in dimesylate 7, or more expeditiously, via trimesylate 21 through alkaline H2O2 mediated cleavage.

Efficient and Rapid Method for the Oxidation of Electron‐Rich Aromatic Aldehydes to Carboxylic Acids Using Improved Basic Hydrogen Peroxide.

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