14265-45-3

Basic information

• Product Name: sulfur trioxide
• Synonyms: Sulfite;SULPHITE
• CAS NO: 14265-45-3
• Molecular Formula: O₃S
• Molecular Weight: 80.06
• EINECS: 231-197-3
• Mol File: 14265-45-3.mol

Chemical Properties

• Boiling Point: °Cat760mmHg
• Flash Point: °C
• Appearance: /
• Density: g/cm³
• Vapor Pressure: 371mmHg at 25°C
• Refractive Index: 1.662
• CAS DataBase Reference: sulfur trioxide(CAS DataBase Reference)
• NIST Chemistry Reference: sulfur trioxide(14265-45-3)
• EPA Substance Registry System: sulfur trioxide(14265-45-3)

Safety Data

• Hazardous Substances Data: 14265-45-3(Hazardous Substances Data)

Usage

Uses

1. Used in Chemical Industry:
Sulfur trioxide is used as a reactant for the production of sulfuric acid (H2SO4), which is a key component in various chemical processes and products, such as fertilizers, detergents, and batteries.
2. Used in Paper Industry:
Sulfur trioxide is used as a catalyst in the Kraft process, which is the dominant method for producing pulp from wood for papermaking. It helps in breaking down the lignin that binds the cellulose fibers in wood, making it easier to separate the fibers and produce paper.
3. Used in Petroleum Industry:
Sulfur trioxide is used in the production of sulfur-containing compounds, such as alkyl sulfonates, which are used as additives in the petroleum industry to improve the performance of fuels and lubricants.
4. Used in Food Industry:
Inorganic sulfites, such as sodium sulfite (Na2O3S), are used as preservatives in the food industry to control microbial growth, prevent browning, and extend the shelf life of various products, including fruits, vegetables, and wine.
5. Used in Cosmetics Industry:
Sulfur trioxide and its inorganic salts, such as sodium sulfite, potassium sulfite, sodium bisulfite, and sodium metabisulfite, are used as reducing agents, hair waving/straightening agents, and antioxidants in cosmetic formulations. They help in improving the texture, appearance, and stability of various cosmetic products.
6. Used in Water Treatment:
Sulfur trioxide is used as a water treatment additive, for example, to control oxygen levels in power plant boiler water, which helps in preventing corrosion and improving the efficiency of the power generation process.
7. Used in Environmental Applications:
Sulfur trioxide can be used to produce sulfur dioxide (SO2), which is a common air pollutant that can be used for various environmental applications, such as the control of sulfur emissions from industrial processes and the treatment of wastewater.

Environmental Fate

Sulfites are generally soluble compounds that interact with the environment through a variety of processes. The primary function of sulfites is that of a reducing agent, which can remove dissolved oxygen from waterways. This reduction of dissolved oxygen (normally produced via normal aeration through water movement, falls and disturbances, etc.) in turn generates a favorable environment for anaerobic bacteria, disrupting the local microbiota. Decreases in dissolved oxygen caused by the presence of sulfites, typically below 5 ppm dissolved oxygen, can negatively affect fish and other organisms present in polluted waterways. Another effect of sulfite contamination of waterways is the production of hydrogen sulfide gas, which is a by-product of sulfite-induced redox processes. Flue gas desulfurization is an industrial process that produces calcium sulfite (CaSO3) as a by-product. This relatively insoluble sulfite, when deposited in soils, can cause a general shift in local microbiot a; however, calcium sulfite readily undergoes oxidation to calcium sulfate (gypsum), which is generally accepted as a remediation material for poor quality soils. While the resulting gypsum can have beneficial effects on soils for agricultural purposes, large quantities of sulfite species over longer time spans can be expected to directly affect microbial communities in soils, even after conversion to the more benign calcium sulfate. Consequently, the presence of calcium sulfate may produce blooming as a result of oxygen- and sulfurenriched soils and adjoining waterways.

Toxicity evaluation

Although the physiological basis for sulfite sensitivity is still poorly understood, clinical observations have established that certain medical conditions are associated with a predisposition to sulfite hypersensitivity. Approximately 500 000 individuals in the United States (<0.05% of the population) are at higher risk because they are asthma sufferers who are steroid dependent or have general airway hypersensitivity. Studies suggest that sulfur dioxide is the agent that causes the highest physiological response. It has been shown that bronchoconstriction as a result of SO2 exposure is controlled by chemosensitive receptors in the tracheobronchial tree. Sensory C-fiber receptors and rapidly activating receptors are sensitive to gases such as SO2, and are found throughout the respiratory tract. Activation of these receptors triggers central nervous system reflexes that culminate in bronchoconstriction, mucosal vasodilation, cough, mucus secretion, apnea, and potential of bradycardia and changes in blood pressure. Inhaled sulfur dioxide elicited a stronger reaction in sulfite oxidase–deficient rats than endogenously accumulated sulfites and S-sulfocysteine (a reaction product of sulfite with cysteine residues in proteins). Bisulfites result in three main reactions with biomolecules: sulfonation (sulfitolysis), autooxidation (and generation of free radicals), and cytosine addition. Sulfonation reactions in the body resulting from exogenous bisulfites can be long-lived in vivo. Autooxidation reactions induced by bisulfites may result in lipid peroxidation, and possible damage to plasma membranes as a result. Sulfite addition to cytosine creates uracil, producing a mutation at that site.

InChI:InChI=1/O3S/c1-4(2)3

Upstream product

• 20901-21-7 disulfur monoxide 
• 15579-17-6 trithionate 
• 57-12-5 cyanide^(1-) 
• 20196-46-7 sulfoxylic acid 
• 857244-78-1 thiotrithiazyl chloride 
• 1310-73-2 sodium hydroxide 
• 7664-93-9 sulfuric acid 
• 1333-74-0 hydrogen 
• 302-04-5 Thiocyanate 
• 7722-84-1 dihydrogen peroxide 
• 20386-50-9 HO₃S₂^(1-) 
• 14383-50-7 thiosulphate ion 
• 12210-38-7 sulfite^(1-) radical 
• 149-44-0 rongalite 

Downstream Products

• 7727-37-9 nitrogen 
• 7446-11-9 sulfur trioxide 
• 10024-97-2 dinitrogen monoxide 
• 12190-75-9 chloroamine 
• 15181-48-3 chlorosulfate anion 
• 10097-32-2 bromide 
• 14808-79-8 Sulfate 
• 84-86-6 4-amino-1-naphthalenesufonic acid 
• 74-90-8 hydrogen cyanide 
• 91-25-8 2-sulfobenzaldehyde 
• 7782-79-8 hydrogen azide 
• 14343-69-2 azide^(1-) 
• 12143-45-2 sulfate radical anion 
• 125499-17-4 4-nitro2-sulfonato-thiophenolate 

Relevant articles and documents

Catalytic activity of CuS nanoparticles in hydrosulfide ions air oxidation

The most efficient technique for H2S removal from the wastewaters is the catalytic aeration of the wastewaters, i.e., H2S oxidation in air-saturated solutions in the presence of catalysts. Photophysical characteristics of colloidal CuS nanoparticles synthesized in various conditions and stabilized in aqueous solutions with sodium polyphosphate were studied. Hydrosulfide ions air oxidation in aqueous solutions at room temperatures and 1 atm proceeded with small rates in the absence of catalysis and increased, substantially upon the injection of CuS nanoparticles into a reacting mixture. The rate of HS- catalytic oxidation grew at an increase in molar CuS concentration, initial concentration of Na2S, volume fraction of oxygen in gas mixture bubbled into the reactor, and pH of a solution (≤ 11.9). A scheme for the mechanism of HS- catalytic oxidation was proposed. According to the scheme, HS- oxidation is a chain radical reaction initiated on the surface of CuS nanoparticles and propagated further in the bulk of a solution.

Oxidation of biologically relevant chalcogenones and their Cu(I) complexes: Insight into selenium and sulfur antioxidant activity

Hydroxyl radical damage to DNA causes disease, and sulfur and selenium antioxidant coordination to hydroxyl-radical-generating Cu+ is one mechanism for their observed DNA damage prevention. To determine how copper binding results in antioxidant

DNA damage induced by sulfite autoxidation catalyzed by copper(II) tetraglycine complexes

Copper(II)/(III) tetraglycine complexes were investigated for their ability to catalyze the autoxidation of sulfite resulting in oxidative DNA damage. The focus of this work is on DNA damage by Cu(III) and oxysulfur radicals formed by the oxidation of S(IV) oxides by dissolved oxygen in the presence of Cu(II) tetraglycine complexes. The results suggest that sulfite is rapidly oxidized by oxygen in the presence of Cu(II) complexes producing Cu(III) tetraglycine, which can be monitored spectrophotometrically at 365 nm. A synergistic effect of Cu(II) with a second metal ion (Ni(II), Co(II) or Mn(II) traces) was observed. The Royal Society of Chemistry 2005.

General Model for the Nonlinear pH Dynamics in the Oxidation of Sulfur(-II) Species

A general kinetic feature has been observed experimentally for the oxidation of the sulfur(-II) species thiosulfate, thiourea, thiocyanate, and sulfide by chlorite and other multi-equivalent oxidants under appropriate, unbuffered batch conditions. This fingerprint consists of an initial rise in pH followed by an autocatalytic drop in pH or oligo-oscillatory behavior. These systems also exhibit oscillations and other complex dynamical behavior in a continuous-flow stirred tank reactor (CSTR). The previously proposed general models that are oxidant based do not successfully explain the observed pH effects. We propose a simple, general model that is based upon the changing oxidation states of sulfur to explain the general pH features. The scheme qualitatively models autocatalysis and oligo-oscillations in batch and simple and complex oscillations in a CSTR. The general model consists of three separate stages: negative hydrogen ion feedback (S(-II) to S(0)), a transition of S(0) to S(IV), and positive proton feedback from S(IV) to S(VI).

The preparation and properties of N-fluoroformyliminosulfur difluoride, SF2=NCOF

The inorganic isocyanates derived from silicon, phosphorus, and sulfur have been found to react readily with sulfur tetrafluoride to give, in common, the novel compound, N-fluoroformyliminosulfur difluoride, SF2=NCOF, the preparation and proper

Evidence for Multistep Reactions in the Iron(III) Catalysed Autoxidation of Sulphur(IV) Oxides: Possible Steps during Acid Rain Formation

Kinetic and spectroscopic evidence is presented for the formation and decomposition of iron(III)-sulphur(IV) transients during the iron(III) catalysed autoxidation of sulphur(IV) oxides in aqueous solution, for which four different reaction steps could be

Kinetics and Mechanism of the Ferrate Oxidation of Thiosulfate and Other Sulfur-Containing Species

The kinetics of the reaction of ferrate, FeO42-, with several sulfur-containing species in aqueous media have been investigated, and the results are reported. It was found that, when the reductant is in excess, ferrate rapidly oxidizes thiosulfate to sulfite, benzenesulfinate to benzenesulfonate, methionine to its corresponding sulfoxide, and dimethyl sulfoxide to dimethyl sulfone. The rate law for each reaction is first order with respect to each reactant and first order with respect to the hydrogen ion concentration. A mechanism for each oxidation reaction is discussed.

Oxidation of thiocyanate with H2O2 catalyzed by [RuIII(edta)(H2O)]-

The [RuIII(edta)(H2O)]- (edta4- = ethylenediaminetetraacetate) complex is shown to catalyze the oxidation of thiocyanate (SCN-) with H2O2 mimicking the action of peroxidases. The kinetics of the catalytic oxidation process was studied by using stopped-flow and rapid scan spectrophotometry as a function of [RuIII(edta)], [H2O2], [SCN-], pH (3.2-9.1) and temperature (15-30 °C). Spectral analyses and kinetic data are suggestive of a catalytic pathway in which hydrogen peroxide reacts directly with thiocyanate coordinated to the RuIII(edta) complex. Catalytic intermediates such as [RuIII(edta)(OOH)]2- and [Ru V(edta)(O)]- were found to be non-reactive in the oxidation process under the specified conditions. Formation of SO 42- and OCN- was identified as oxidation products in ESI-MS experiments. A detailed mechanism in agreement with the spectral and kinetic data is presented. The Royal Society of Chemistry 2013.

The kinetics and mechanism of the oxidation of inorganic oxysulfur compounds by potassium ferrate: Part I. Sulfite, thiosulfate and dithionite ions

The kinetics and mechanism of the oxidation of the sulfite (SO32-), thiosulfate (S2O32-) and dithionite (S2O42-) ions by ferrate (FeO42-) ions was studied under pseudo-first-order conditions and, in addition, the reaction with thiosulfate ions was studied under non-pseudo-first-order conditions. Previous work on sulfite and thiosulfate was repeated and extended, specifically over a larger pH range, and using non-pseudo-first-order kinetics. Dithionite was only studied at high pH values because of rapid hydrolysis below a pH of about 10. The kinetics for sulfite and thiosulfate showed a first-order dependence on hydrogen, oxysulfur and ferrate ion concentrations at high pH values, but became independent of the hydrogen ion concentration below a pH of about 8.5. The kinetics for dithionite involved two terms, one being first-order in the hydrogen, dithionite and ferrate ion concentrations, and the other being first-order in only the dithionite and ferrate ions. For all three reductants the proposed mechanism has a rate-determining step involving reaction between the protonated ferrate and the oxysulfur ions. For dithionite there is also a rate-determining step involving reaction between unprotonated ferrate and dithionite. All the oxysulfur ions gave Fe(III) as a product. Sulfite produced sulfate, whereas thiosulfate and dithionite gave sulfite.

Some perfluoroalkyliminosulfur derivatives

Trifluoromethyliminosulfur dichloride and pentafluoroethyliminosulfur dichloride are prepared by reaction of aluminum trichloride with trifluoromethyliminosulfur difluoride and pentafluoroethyliminosulfur difluoride, respectively. These imino dichlorides