Search results for "Oxidizing agent"

Oxygen, Its Nature and Chemistry: What Is so Special About This Element?

2010

It would seem that an introduction to oxygen is unnecessary, for we deal with it and depend upon it every moment of our lives. Oxygen is to us the essential stuff of the air we breathe. We are aerobic animals who obtain energy by oxidizing foodstuffs. As such, we are wholly dependent on oxygen for life – go without it for a couple of minutes and we panic and may even suffer irreversible brain damage. In a few more minutes, we perish. Animal metabolism depends upon oxygen for almost all of its energy-generating processes. Yet this was not always so. Early in the history of the Earth, there was essentially no free oxygen anywhere, although oxygen has always been one of the most abundant eleme…

Versatile oxidative approach to carbazoles and related compounds using MoCl5.

2013

The unique oxidizing power of molybdenum pentachloride provides an easy to perform, versatile, and high yielding method to construct carbazoles and the corresponding dibenzo analogues of thiophene, furan, and selenophene. The coupling reaction tolerates a variety of functional groups. The synthesis is highly modular. By this approach a precursor for the naturally occurring carbazole koenigicine was prepared.

Ceric Ammonium Nitrate - a versatile oxidizing reagent

1994

ChemInform Abstract: Ceric Ammonium Nitrate - A Versatile Oxidizing Reagent

2010

ESR study of thianthrenium radical cation within acid zeolites

1997

Abstract Thianthrene (E ox = 1.47 V vs NHE) has been adsorbed into a series of zeolites beta (s) and ZSM-5 in the NH 4 + or H + forms, having different particle size and Si/Al ratio. The resulting population of generated thianthrenium radical cation was determined by a combination of diffuse reflectance and ESR spectroscopies. From the results obtained it can be concluded: i) the process takes predominantly place in the interior of the voids (XPS measurements and lack of influence of the particle size); ii) ZSM-5 is more efficient than zeolite s; iii) no strong acid sites are required (both NH 4 + and H + forms produced very similar spin concentrations); iv) the zeolite framework acts isola…

Effect of ozone and hydrogen peroxide on off-flavor compounds and water quality in a recirculating aquaculture system

2022

The recirculating aquaculture system (RAS) is an ever-developing technology for producing fish with a low environmental impact. However, off-flavors can be a major problem in RAS fish production. Off-flavor compounds are of microbial origin and are accumulated in fish flesh. They typically cause a musty and earthy taste and odor, which consumers find unacceptable. Here we hypothesized that oxidizing compounds such as ozone (O3), hydrogen peroxide (H2O2), and their combinations, referred to as advanced oxidation processes (AOP)s, can remove or decrease these compounds in water and prevent their accumulation in fish. In this study, four different oxidative treatments (O3 low (0.4 mg O3 L−1), …

Sol-gel entrapped chromium(VI): a new selective, efficient and recyclable oxidizing system

2001

Abstract The sol-gel entrapment of chromium(VI) within a silica matrix, obtained by oxidation with ozone of the corresponding entrapped chromium(III), was found to be an efficient and recyclable oxidizing system (at least up to 16 times) for benzylic alcohols. No leaching of chromium in solution was observed, which prevented any environmental pollution.

ChemInform Abstract: Sol-Gel Entrapped Chromium(VI): A New Selective, Efficient and Recyclable Oxidizing System.

2010

Abstract The sol-gel entrapment of chromium(VI) within a silica matrix, obtained by oxidation with ozone of the corresponding entrapped chromium(III), was found to be an efficient and recyclable oxidizing system (at least up to 16 times) for benzylic alcohols. No leaching of chromium in solution was observed, which prevented any environmental pollution.

Aluminum tri-isopropoxide as an alternative precursor for atomic layer deposition of aluminum oxide thin films

2019

Due to the safety challenges associated with the use of trimethylaluminum as a metal precursor for the deposition of alumina, different chemicals have been investigated over the years to replace it. The authors have investigated the use of aluminum tri-isopropoxide (TIPA) as an alternative alkoxide precursor for the safe and cost-effective deposition of alumina. In this work, TIPA is used as a stable Al source for atomic layer deposition (ALD) of Al2O3 when different oxidizing agents including water, oxygen plasma, water plasma, and ozone are employed. The authors have explored the deposition of Al2O3 using TIPA in ALD systems operating in vacuum and atmospheric pressure conditions. For the…

Preparation of tungstophosphoric acid/cerium-doped NH2-UiO-66 Z-scheme photocatalyst: a new candidate for green photo-oxidation of dibenzothiophene a…

2021

International audience; The goal of this study was to introduce an effective visible-light induced photocatalytic system with a good ability for photocatalytic oxidative desulfurization (PODS) and denitrogenation (PODN) using molecular oxygen (O2) as an oxidant. In this regard, tungestophosphoric acid (PW12) was supported onto cerium-doped NH2-UiO-66 (PW12/Ce-NUiO-66) and employed for the photo-oxidation of dibenzothiophene (DBT) and quinoline (Qu). Herein, using cerium (Ce) as a “mediator” facilitated the separation of charge carriers, while NH2-UiO-66 remarkably enhanced the surface area with plentiful adsorption sites and shifted the adsorption edge of PW12to the visible region. The sum …