|
Tetra-n-butylammonium
Tetrabutylammonium bromide (TBAB) is a quaternary ammonium salt with a bromide commonly used as a phase transfer catalyst. It is used to prepare many other tetrabutylammonium salts by salt metathesis reactions. The anhydrous form is a white solid. In addition to being cheap, tetrabutylammonium bromide is also environmentally friendly, has a greater degree of selectivity, is operationally simple, non-corrosive, and can be recycled easily as well. Preparation and reactions Tetrabutylammonium bromide can be prepared by the alkylation of tributylamine with 1-bromobutane. Tetrabutylammonium bromide is used to prepare other salts of the tetrabutylammonium cation by salt metathesis reactions., , ;. It serves as a source of bromide ions for substitution reactions. It is one of a commonly-used phase transfer catalyst. As its melting point is just over 100 °C and decreases in the presence of other reagents, it can be considered an ionic liquid. Role in semi-clathrate formation TBAB ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetrabutylammonium Tribromide
Tetrabutylammonium tribromide, abbreviated to TBATB, is a pale orange solid with the formula (C4H9)4r3. It is a salt of the lipophilic tetrabutylammonium cation and the linear tribromide anion. The salt is sometimes used as a reagent used in organic synthesis as a conveniently weighable, solid source of bromine. Preparation The compound is prepared by treatment of solid tetra-''n''-butylammonium bromide with bromine vapor: : (C4H9)4r + Br2 → (C4H9)4r3 Instead of bromine, tetra-''n''-butylammonium bromide can also be reacted with vanadium pentoxide and aqueous hydrogen peroxide, or alternatively with ceric ammonium nitrate. This molecule is commonly used as a catalyst in reactions involving the Fischer–Speier esterification mechanism and was heavily tested on by Dr Divyam Shard and Dr Arnav Mohammed, co-workers at Hustlers' University while working with Mr Atul Gowande. See also *Tribromide *Tetrabutylammonium triiodide Tetra-''n''-butylammonium triiodide (TBAI3 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetra-n-butylammonium Iodide
Tetra-''n''-butylammonium iodide (TBAI) is a quaternary ammonium salt with an iodide counterion. It is used for synthesizing tetra-''n''-butylammonium triiodide by mixing with iodine. Properties The solid crystal of tetra-''n''-butylammonium iodide is in the monoclinic crystal system. It has space group ''C''2/''c''. The unit cell has dimensions a=14.2806 b=14.1864 c=19.5951 β=111.149. There are eight formulae in the unit cell (Z=8), which has volume 3702.4 Å3. The enthalpy of formation ΔfH0 of tetra-''n''-butylammonium iodide is −499 kJ/mol, which is lower than that for the bromide or chloride (−540, −564 kJ/mol). At lower temperatures with water tetra-''n''-butylammonium iodide forms a clathrate hydrate. The tetra-''n''-butylammonium cation is large and hydrophobic. The absolute enthalpy of hydration (from gas phase) is −260 kJ/mol. The He(I) photoelectron spectrum of tetra-''n''-butylammonium iodide contains a peak at 11 eV due to the te ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phase Transfer Catalyst
In chemistry, a phase-transfer catalyst or PTC is a catalyst that facilitates the transition of a reactant from one phase into another phase where reaction occurs. Phase-transfer catalysis is a special form of heterogeneous catalysis. Ionic reactants are often soluble in an aqueous phase but insoluble in an organic phase in the absence of the phase-transfer catalyst. The catalyst functions like a detergent for solubilizing the salts into the organic phase. Phase-transfer catalysis refers to the acceleration of the reaction upon the addition of the phase-transfer catalyst. By using a PTC process, one can achieve faster reactions, obtain higher conversions or yields, make fewer byproducts, eliminate the need for expensive or dangerous solvents that will dissolve all the reactants in one phase, eliminate the need for expensive raw materials and/or minimize waste problems. Phase-transfer catalysts are especially useful in green chemistry—by allowing the use of water, the nee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetrabutylammonium Chloride
Tetrabutylammonium chloride is the organic compound with the formula (C4H9)4NCl. A white water-soluble solid, it is a quaternary ammonium salt of chloride. It is a precursor to other tetrabutylammonium salts. Often tetrabutylammonium bromide Tetrabutylammonium bromide (TBAB) is a quaternary ammonium salt with a bromide commonly used as a phase transfer catalyst. It is used to prepare many other tetrabutylammonium salts by salt metathesis reactions. The anhydrous form is a white soli ... is preferred as a source of tetrabutylammonium because it is less hygroscopic than the chloride. References Tetrabutylammonium salts Chlorides {{organic-compound-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetrabutylammonium Hydroxide
Tetrabutylammonium hydroxide is the chemical compound with the formula (C4H9)4NOH, abbreviated Bu4NOH with the acronym TBAOH or TBAH. This species is employed as a solution in water or alcohols. It is a common base in organic chemistry. Relative to more conventional inorganic bases, such as KOH and NaOH, Bu4NOH is more soluble in organic solvents.. Preparation and reactions Solutions of Bu4NOH are usually prepared ''in situ'' from butylammonium halides, Bu4NX, for example by reacting them with silver oxide or using an ion exchange resin. Attempts to isolate Bu4NOH induces Hofmann elimination, leading to Bu3N and 1-butene. Solutions of Bu4NOH are typically contaminated with Bu3N for this reason. Treatment of Bu4NOH with a wide range of acids gives water and the other tetrabutylammonium salts: Bu4NOH + HX -> Bu4NX + H2O Applications Bu4NOH is a strong base that is used often under phase-transfer conditions to effect alkylations and deprotonations. Typical reactions include benz ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetramethylammonium Bromide
Tetramethylammonium (TMA) or (Me4N+) is the simplest quaternary ammonium cation, consisting of four methyl groups attached to a central nitrogen atom, and is isoelectronic with neopentane. It is positively charged and can only be isolated in association with a counter-ion. Common salts include tetramethylammonium chloride and tetramethylammonium hydroxide. Tetramethylammonium salts are commonly used in chemical synthesis and are widely employed in pharmacological research. Common nomenclature In the toxicological literature, ''naturally occurring'' tetramethylammonium (anion unspecified) is often referred to by the name "tetramine". Unfortunately, this non-systematic or "trivial" name is also used for other chemical entities, including a toxic rodenticide (Tetramethylenedisulfotetramine). Similarly, the acronym "TMA", which is frequently used for tetramethylammonium in the pharmacological literature, may also refer to the investigational drug 3,4,5-trimethoxyamphetamine, which, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetraethylammonium Bromide
Tetraethylammonium bromide (TEAB) is a quaternary ammonium compound with the chemical formula C8H20N+Br−, often written as "Et4N+Br−" in the chemical literature. It has been used as the source of tetraethylammonium ions in pharmacological and physiological studies, but is also used in organic chemical synthesis. Chemistry Synthesis TEAB is commercially available, but can be prepared by the reaction between tetraethylammonium hydroxide and hydrobromic acid: :Et4N+HO− + HBr → Et4N+Br− + H2O Evaporation of the water and recrystallization from acetonitrile yields a crystalline sample of TEAB. Structure The crystal structure of TEAB has been determined and found to exhibit a distorted tetrahedral symmetry with respect to the geometry of the C atoms around the central N. Synthetic applications Examples include: * TEAB catalyzes the high-yield oxidation of organic sulfides to sulfoxides by o-iodoxybenzoic acid (IBX) in chloroform/water at room temperature, e.g. :(C2H5) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quaternary Ammonium Salt
In chemistry, quaternary ammonium cations, also known as quats, are positively charged polyatomic ions of the structure , R being an alkyl group or an aryl group. Unlike the ammonium ion () and the primary, secondary, or tertiary ammonium cations, the quaternary ammonium cations are permanently charged, independent of the pH of their solution. Quaternary ammonium salts or quaternary ammonium compounds (called quaternary amines in oilfield parlance) are salts of quaternary ammonium cations. Polyquats are a variety of engineered polymer forms which provide multiple quat molecules within a larger molecule. Quats are used in consumer applications including as antimicrobials (such as detergents and disinfectants), fabric softeners, and hair conditioners. As an antimicrobial, they are able to inactivate enveloped viruses (such as SARS-CoV-2). Quats tend to be gentler on surfaces than bleach-based disinfectants, and are generally fabric-safe. Synthesis Quaternary ammonium comp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bromide
A bromide ion is the negatively charged form (Br−) of the element bromine, a member of the halogens group on the periodic table. Most bromides are colorless. Bromides have many practical roles, being found in anticonvulsants, flame-retardant materials, and cell stains. Although uncommon, chronic toxicity from bromide can result in bromism, a syndrome with multiple neurological symptoms. Bromide toxicity can also cause a type of skin eruption, see potassium bromide. The bromide ion has an ionic radius of 196 pm. Natural occurrence Bromide is present in typical seawater (35 PSU) with a concentration of around 65 mg/L, which is about 0.2% of all dissolved salts. Seafood and deep sea plants generally have higher levels than land-derived foods. Bromargyrite—natural, crystalline silver bromide—is the most common bromide mineral known but is still very rare. In addition to silver, bromine is also in minerals combined with mercury and copper. Formation and react ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetra-n-butylammonium Fluoride
Tetra-''n''-butylammonium fluoride, commonly abbreviated to TBAF and ''n''-Bu4NF, is a quaternary ammonium salt with the chemical formula (CH3CH2CH2CH2)4N+F−. It is commercially available as the white solid trihydrate and as a solution in tetrahydrofuran. TBAF is used as a source of fluoride ion in organic solvents. Preparation and properties TBAF can be prepared by passing hydrofluoric acid through an ion-exchange resin, followed by tetrabutylammonium bromide. Upon evaporation of the water, TBAF can be collected as an oil in quantitative yield. Preparing anhydrous samples is of interest as the basicity of fluoride increases by more than 20 p''K'' units on passing from aqueous to aprotic solvent. However, heating samples of the hydrated material to 77 °C under vacuum causes decomposition to the hydrogen difluoride salt. Similarly, samples dried at 40 °C under high vacuum still contain 10-30 mol% of water and some 10% of difluoride. Instead, anhydrous TBAF ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetrabutylammonium
Tetrabutylammonium is a quaternary ammonium cation with the formula (C4H9)4sup>+. It is used in the research laboratory to prepare lipophilic salts of inorganic anions. Relative to tetraethylammonium derivatives, tetrabutylammonium salts are more lipophilic but crystallize less readily. Derivatives Some tetrabutylammonium salts of simple anions include: *tetrabutylammonium fluoride, a desilylation reagent. *tetrabutylammonium bromide, a precursor to other tetrabutylammonium salts via salt metathesis reactions. *tetrabutylammonium iodide, a low cost catalyst. *tetrabutylammonium triiodide, a common carrier of the triiodide anion used in chemical synthesis. *tetrabutylammonium hydroxide, a precursor to other tetrabutylammonium salts via acid-base reactions. *tetrabutylammonium hexafluorophosphate, an electrolyte for nonaqueous electrochemistry. Some tetrabutylammonium salts of more complex examples include: *polyoxometalates. *NS. * metal carbonyl anions. *Synthetic iron-sulfur clu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salt Metathesis
A salt metathesis reaction, sometimes called a double displacement reaction, is a chemical process involving the exchange of bonds between two reacting chemical species which results in the creation of products with similar or identical bonding affiliations. This reaction is represented by the general scheme: :AB + CD -> AD + CB The bond between the reacting species can be either ionic or covalent. Classically, these reactions result in the precipitation of one product. In older literature, the term double decomposition is frequently encountered. The term double decomposition is more specifically used when at least one of the substances does not dissolve in the solvent, as the ligand or ion exchange takes place in the solid state of the reactant. For example: :AX(aq) + BY(s) → AY(aq) + BX(s). Types of reactions Counterion exchange Salt metathesis is a common technique for exchanging counterions. The choice of reactants is guided by a solubility chart or lattice energy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.png "Click for more on -> Tetramethylammonium Bromide")
