Quaternary Ammonium Cation - Wikipedia
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Common Names for Selected Aromatic Groups
More Nomenclature: Common Names for Selected Aromatic Groups Phenyl group = or Ph = C6H5 = Aryl = Ar = aromatic group. It is a broad term, and includes any aromatic rings. Benzyl = Bn = It has a -CH2- (methylene) group attached to the benzene ring. This group can be used to name particular compounds, such as the one shown below. This compound has chlorine attached to a benzyl group, therefore it is called benzyl chloride. Benzoyl = Bz = . This is different from benzyl group (there is an extra “o” in the name). It has a carbonyl attached to the benzene ring instead of a methylene group. For example, is named benzoyl chloride. Therefore, it is sometimes helpful to recognize a common structure in order to name a compound. Example: Nomenclature: 3-phenylpentane Example: This is Amaize. It is used to enhance the yield of corn production. The systematic name for this compound is 2,4-dinitro-6-(1-methylpropyl)phenol. Polynuclear Aromatic Compounds Aromatic rings can fuse together to form polynuclear aromatic compounds. Example: It is two benzene rings fused together, and it is aromatic. The electrons are delocalized in both rings (think about all of its resonance form). Example: This compound is also aromatic, including the ring in the middle. All carbons are sp2 hybridized and the electron density is shared across all 5 rings. Example: DDT is an insecticide and helped to wipe out malaria in many parts of the world. Consequently, the person who discovered it (Muller) won the Nobel Prize in 1942. The systematic name for this compound is 1,1,1-trichloro-2,2-bis-(4-chlorophenyl)ethane. -
Antiseptics and Disinfectants for the Treatment Of
Verstraelen et al. BMC Infectious Diseases 2012, 12:148 http://www.biomedcentral.com/1471-2334/12/148 RESEARCH ARTICLE Open Access Antiseptics and disinfectants for the treatment of bacterial vaginosis: A systematic review Hans Verstraelen1*, Rita Verhelst2, Kristien Roelens1 and Marleen Temmerman1,2 Abstract Background: The study objective was to assess the available data on efficacy and tolerability of antiseptics and disinfectants in treating bacterial vaginosis (BV). Methods: A systematic search was conducted by consulting PubMed (1966-2010), CINAHL (1982-2010), IPA (1970- 2010), and the Cochrane CENTRAL databases. Clinical trials were searched for by the generic names of all antiseptics and disinfectants listed in the Anatomical Therapeutic Chemical (ATC) Classification System under the code D08A. Clinical trials were considered eligible if the efficacy of antiseptics and disinfectants in the treatment of BV was assessed in comparison to placebo or standard antibiotic treatment with metronidazole or clindamycin and if diagnosis of BV relied on standard criteria such as Amsel’s and Nugent’s criteria. Results: A total of 262 articles were found, of which 15 reports on clinical trials were assessed. Of these, four randomised controlled trials (RCTs) were withheld from analysis. Reasons for exclusion were primarily the lack of standard criteria to diagnose BV or to assess cure, and control treatment not involving placebo or standard antibiotic treatment. Risk of bias for the included studies was assessed with the Cochrane Collaboration’s tool for assessing risk of bias. Three studies showed non-inferiority of chlorhexidine and polyhexamethylene biguanide compared to metronidazole or clindamycin. One RCT found that a single vaginal douche with hydrogen peroxide was slightly, though significantly less effective than a single oral dose of metronidazole. -
A Facile Procedure for the Generation of Dichlorocarbene from the Reaction of Carbon Tetrachloride and Magnesium Using Ultrasonic Irradiation
Molecules 2003, 8, 608-613 molecules ISSN 1420-3049 http://www.mdpi.org A Facile Procedure for the Generation of Dichlorocarbene from the Reaction of Carbon Tetrachloride and Magnesium using Ultrasonic Irradiation Haixia Lin *, Mingfa Yang, Peigang Huang and Weiguo Cao Department of Chemistry, Shanghai University, Shanghai, 200436, P.R. China *Author to whom correspondence should be addressed: e-mail [email protected] Received: 7 April 2003; in revised form: 7 July 2003 / Accepted: 20 July 2003 / Published: 31 July 2003 Abstract: An improved method for the generation of dichlorocarbene was developed that utilizes ultrasound in the reaction of carbon tetrachloride with magnesium. High yields of gem-dichlorocyclopropane derivatives can be obtained in the presence of olefins by this method. Keywords: Dichlorocarbene; gem-dichlorocyclopropanes; ultrasonic irradiation; olefin addition; magnesium Introduction Gem-dichlorocyclopropanes are valuable intermediates in organic synthesis [1,2]. They are typically prepared by the addition of dichlorocarbene to olefins under phase-transfer catalysis conditions [3-5]. Sonochemical generation of dichlorocarbene has also been reported [6-8]. The reactions of dichlorocarbene with olefins in solid-liquid two-phase systems using ultrasonication usually afford high yields of double-bond addition products. In addition, excellent yields of diadducts have been obtained from dienes and dichlorocarbene under ultrasonication and phase-transfer catalyst [9]. Molecules 2003, 8 609 Previously, we reported a novel route for the generation of dichlorocarbene by the reaction of carbon tetrachloride with magnesium in a neutral medium and hypothesized that the mechanism of these reactions might involve a single electron transfer [10]. However, these reactions suffered from several experimental drawbacks: some of the major ones being the sudden exotherm that occurs after an unpredictable induction period, foaming, and in some cases, the use of iodine as the activating agent. -
Fischer Carbene Complexes in Organic Synthesis Ke Chen 1/31/2007
Baran Group Meeting Fischer Carbene Complexes in Organic Synthesis Ke Chen 1/31/2007 Ernst Otto Fischer (1918 - ) Other Types of Stabilized Carbenes: German inorganic chemist. Born in Munich Schrock carbene, named after Richard R. Schrock, is nucleophilic on November 10, 1918. Studied at Munich at the carbene carbon atom in an unpaired triplet state. Technical University and spent his career there. Became director of the inorganic Comparision of Fisher Carbene and Schrock carbene: chemistry institute in 1964. In the 1960s, discovered a metal alkylidene and alkylidyne complexes, referred to as Fischer carbenes and Fischer carbynes. Shared the Nobel Prize in Chemistry with Geoffery Wilkinson in 1973, for the pioneering work on the chemistry of organometallic compounds. Schrock carbenes are found with: Representatives: high oxidation states Isolation of first transition-metal carbene complex: CH early transition metals Ti(IV), Ta(V) 2 non pi-acceptor ligands Cp2Ta CH N Me LiMe Me 2 2 non pi-donor substituents CH3 (CO) W CO (CO)5W 5 (CO)5W A.B. Charette J. Am. Chem. Soc. 2001, 123, 11829. OMe O E. O. Fischer, A. Maasbol, Angew. Chem. Int. Ed., 1964, 3, 580. Persistent carbenes, isolated as a crystalline solid by Anthony J. Arduengo in 1991, can exist in the singlet state or the triplet state. Representative Fischer Carbenes: W(CO) Cr(CO) 5 5 Fe(CO)4 Mn(CO)2(MeCp) Co(CO)3SnPh3 Me OMe Ph Ph Ph NEt2 Ph OTiCp2Cl Me OMe Foiled carbenes were defined as "systems where stabilization is Fischer carbenes are found with : obtained by the inception of the facile reaction which is foiled by the impossibility of attaining the final product geometry". -
Quaternary Ammonium Compounds
FACT SHEET: Quaternary Ammonium Compounds Quaternary ammonium compounds, also known as “quats” or “QACs,” include a number of chemicals used as sanitizers and disinfectants, including benzalkonium chloride, benzethonium chloride, cetalkonium chloride, cetrimide, cetrimonium bromide, cetylpyridinium chloride, glycidyl trimethyl, ammonium chloride, and stearalkonium chloride.[i] In general, quats cause toxic effects through all Mutagenicity routes of exposure including inhalation, Some quats have shown to be mutagenic and to ingestion, dermal application, and irrigation of damage animal DNA and DNA in human body cavities. Exposure to diluted solutions may lymphocytes at much lower levels than are result in mild irritation, while concentrated present in cleaning chemicals.[6] solutions are corrosive, causing burns to the skin and mucous Membranes. They can produce Antimicrobial Resistance systemic toxicity and can also cause allergic Genes have been discovered that mediate reactions.[2] resistance to quats. There has been an association of some of these genes with beta lactamase genes, Asthma and Allergies raising concern for a relationship between Of particular interest with regard to use as disinfectant resistance and antibiotic resistance.[7] disinfectants in the COVID-19 pandemic, quats increase the risk for asthma and allergic Reproductive Toxicity sensitization. Evidence from occupational Mice whose cages were cleaned with QACs had exposures shows increased risk of rhinitis and very low fertility rates. [8] Exposure to a common asthma -
Chloroform 18.08.2020.Pdf
Chloroform Chloroform, or trichloromethane, is an organic compound with formula CHCl3. It is a colorless, sweet-smelling, dense liquid that is produced on a large scale as a precursor to PTFE. It is also a precursor to various refrigerants. It is one of the four chloromethanes and a trihalomethane. It is a powerful anesthetic, euphoriant, anxiolytic and sedative when inhaled or ingested. Formula: CHCl₃ IUPAC ID: Trichloromethane Molar mass: 119.38 g/mol Boiling point: 61.2 °C Density: 1.49 g/cm³ Melting point: -63.5 °C The molecule adopts a tetrahedral molecular geometry with C3v symmetry. Chloroform volatilizes readily from soil and surface water and undergoes degradation in air to produce phosgene, dichloromethane, formyl chloride, carbon monoxide, carbon dioxide, and hydrogen chloride. Its half-life in air ranges from 55 to 620 days. Biodegradation in water and soil is slow. Chloroform does not significantly bioaccumulate in aquatic organisms. Production:- In industry production, chloroform is produced by heating a mixture of chlorine and either chloromethane (CH3Cl) or methane (CH4). At 400–500 °C, a free radical halogenation occurs, converting these precursors to progressively more chlorinated compounds: CH4 + Cl2 → CH3Cl + HCl CH3Cl + Cl2 → CH2Cl2 + HCl CH2Cl2 + Cl2 → CHCl3 + HCl Chloroform undergoes further chlorination to yield carbon tetrachloride (CCl4): CHCl3 + Cl2 → CCl4 + HCl The output of this process is a mixture of the four chloromethanes (chloromethane, dichloromethane, chloroform, and carbon tetrachloride), which can then be separated by distillation. Chloroform may also be produced on a small scale via the haloform reaction between acetone and sodium hypochlorite: 3 NaClO + (CH3)2CO → CHCl3 + 2 NaOH + CH3COONa Deuterochloroform[ Deuterated chloroform is an isotopologue of chloroform with a single deuterium atom. -
Decolorization of Reactive Orange 16 Via Ferrate(VI) Oxidation Assisted by Sonication
Turkish Journal of Chemistry Turk J Chem (2017) 41: 577 { 586 http://journals.tubitak.gov.tr/chem/ ⃝c TUB¨ ITAK_ Research Article doi:10.3906/kim-1701-8 Decolorization of reactive orange 16 via ferrate(VI) oxidation assisted by sonication Serkan S¸AHINKAYA_ ∗ Department of Environmental Engineering, Faculty of Engineering and Architecture, Nev¸sehirHacı Bekta¸sVeli University, Nev¸sehir,Turkey Received: 02.01.2017 • Accepted/Published Online: 24.03.2017 • Final Version: 05.09.2017 Abstract: The decolorization of azo dye C.I. reactive orange 16 (RO 16) via ferrate(VI) and sono-ferrate(VI) methods, which is the combination of the ferrate(VI) oxidation method with sonication, has been achieved in the present study. The influences of some important operating parameters, which are the initial pH, the concentration of potassium ferrate(VI) (K 2 FeO 4) and the RO 16 dye, and ultrasonic density (for only the sono-ferrate(VI) method), on the color removal have −1 been investigated. The optimum conditions have been determined as pH = 7 and [K 2 FeO 4 ] = 50 mg L for the −1 −1 individual ferrate(VI) oxidation method and pH = 7 and [K 2 FeO 4 ] = 50 mg L by direct sonication at 0.50 W mL ultrasonic density and 20 kHz fixed frequency for the sono-ferrate(VI) method. The color removal efficiencies were 85% by ferrate(VI) method and 91% by sono-ferrate(VI) method. Kinetic studies were also performed for the decolorization of RO 16 under the optimized conditions at room temperature. It was seen that the oxidative decolorization of RO 16 via the sono-ferrate(VI) method happened more rapidly because of the production of OH • radical through sonication compared to the individual ferrate(VI) method. -
23.5 Basicity and Acidity of Amines
23_BRCLoudon_pgs5-0.qxd 12/8/08 1:22 PM Page 1122 1122 CHAPTER 23 • THE CHEMISTRY OF AMINES alkylamines, this resonance occurs at rather small chemical shift—typically around d 1. In aromatic amines, this resonance is at greater chemical shift, as in the second of the preceding examples. Like the OH protons of alcohols, phenols, and carboxylic acids, the NH protons of amines under most conditions undergo rapid exchange (Secs. 13.6 and 13.7D). For this reason, split- ting between the amine N H and adjacent C H groups is usually not observed. Thus, in the NMR spectrum of diethylamine,L the N H resonanceL is a singlet rather than the triplet ex- pected from splitting by the adjacent CHL2 protons. In some amine samples, the N H resonance is broadened and, like the OL H protonL of alcohols, it can be obliterated fromL the spectrum by exchange with D2O (the “DL2O shake,” p. 611). The characteristic 13C NMR absorptions of amines are those of the a-carbons—the carbons attached directly to the nitrogen. These absorptions occur in the d 30–50 chemical-shift range. As expected from the relative electronegativities of oxygen and nitrogen, these shifts are somewhat less than the a-carbon shifts of ethers. PROBLEMS 23.4 Identify the compound that has an M 1 ion at mÜz 136 in its CI mass spectrum, an IR 1 + = absorption at 3279 cm_ , and the following NMR spectrum: d 0.91 (1H, s), d 1.07 (3H, t, J 7Hz), d 2.60 (2H, q, J 7Hz), d 3.70 (2H, s), d 7.18 (5H, apparent s). -
Kinetic Studies on Permanganate Oxidation of Acetophenones Under
Indi an Journal of Chemistry Vol. 40A, June 2001, pp. 610-612 Kinetic studies on permanganate oxidation of The ketones were further purified by vacuum acetophenones under phase transfer catalysis distillation. The solvents employed were purified by standard methods and doubly distilled water was P S Sheeba & T D Radhakrishnan Nair* always used. The catalysts used were tricapryl Department of Chemistry, Calicut University methylammonium chloride (TCMAC) and tetrabutyl Calicut University P.O., Kerala 673 635. India ammonium bromide (TBAB). The former has Received 18 October 2000; revised 8 March 2001 relatively larger organic structure (C 10H21 )JN+CH 3Cr compared to the latter (C4 H9) 4N+B(. Kinetic studies on the permanganate oxidation of The solutions containing the permanganate ions in acetopheno_ne and some of its substituents in organic media using the organic solvents were prepared by shaking the techn1que of phase transfer catalysis are reported. aqueous potassium permanganate solution with the Tncaprylmethylammonium chloride and tetrabutylammonium bromide have been used as the phase transfer catalysts. The organic solvents contammg the phase transfer 4 reaction shows first order dependence each on [ketones] and the catalysts as reported elsewhere . The solutions of the [permanganate ions] respectively . The rate coefficients fit well oxidant thus prepared in the organic solvent and the with the Hammett equation and the p-value calculated aorees well substrate in the organic solvent were thermally with the reaction requirements. "' equilibrated (± 0.05°C) at the desired temperature for Potassium permanganate is a powerful oxidizing about half an hour before mixing. Kinetic runs were carried out under pseudo-first order conditions. -
ANNEX VI List of Preservatives Allowed for Use in Cosmetic Products
ANNEX VI List of preservatives allowed for use in cosmetic products ANNEX VI LIST OF PRESERVATIVES WHICH COSMETIC PRODUCTS MAY CONTAIN Preamble 1. Preservatives are substances which may be added to cosmetic products for the primary purpose of inhibiting the development of micro-organisms in such products. 2. The substances marked with the symbol (+) may also be added to cosmetic products in concentration other than those laid down in this ANNEX for other purposes apparent from the presentation of the products, e.g. as deodorants in soaps or as anti-dandruff agents in shampoos. 3. Other substances used in the formulation of cosmetic products may also have anti-microbial properties and thus help in the preservation of the products, as, for instance, many essential oils and some alcohols. These substances are not included in the ANNEX. 4. For the purposes of this list - “Salts” is taken to mean: salts of the cations sodium, potassium, calcium, magnesium, ammonium, and ethanolamines; salts of the anions chloride, bromide, sulphate, acetate. - “Esters” is taken to mean: esters of methyl, ethyl, propyl, isopropyl, butyl, isobutyl, phenyl. 5. All finished products containing formaldehyde or substances in this ANNEX and which release formaldehyde must be labelled with the warning “contains formaldehyde” where the concentration of formaldehyde in the finished product exceeds 0.05%. Revised as per August 2015 ASEAN Cosmetic Documents 1 Annex VI – Part 1 – List of preservatives allowed for use in cosmetic products ANNEX VI – PART 1 LIST OF PRESERVATIVES ALLOWED Reference Substance Maximum authorized Limitations and Conditions of use and Number concentration requirements warnings which must be printed on the label a b c d e 1 Benzoic acid (CAS No. -
2 Reactions Observed with Alkanes Do Not Occur with Aromatic Compounds 2 (SN2 Reactions Never Occur on Sp Hybridized Carbons!)
Reactions of Aromatic Compounds Aromatic compounds are stabilized by this “aromatic stabilization” energy Due to this stabilization, normal SN2 reactions observed with alkanes do not occur with aromatic compounds 2 (SN2 reactions never occur on sp hybridized carbons!) In addition, the double bonds of the aromatic group do not behave similar to alkene reactions Aromatic Substitution While aromatic compounds do not react through addition reactions seen earlier Br Br Br2 Br2 FeBr3 Br With an appropriate catalyst, benzene will react with bromine The product is a substitution, not an addition (the bromine has substituted for a hydrogen) The product is still aromatic Electrophilic Aromatic Substitution Aromatic compounds react through a unique substitution type reaction Initially an electrophile reacts with the aromatic compound to generate an arenium ion (also called sigma complex) The arenium ion has lost aromatic stabilization (one of the carbons of the ring no longer has a conjugated p orbital) Electrophilic Aromatic Substitution In a second step, the arenium ion loses a proton to regenerate the aromatic stabilization The product is thus a substitution (the electrophile has substituted for a hydrogen) and is called an Electrophilic Aromatic Substitution Energy Profile Transition states Transition states Intermediate Potential E energy H Starting material Products E Reaction Coordinate The rate-limiting step is therefore the formation of the arenium ion The properties of this arenium ion therefore control electrophilic aromatic substitutions (just like any reaction consider the stability of the intermediate formed in the rate limiting step) 1) The rate will be faster for anything that stabilizes the arenium ion 2) The regiochemistry will be controlled by the stability of the arenium ion The properties of the arenium ion will predict the outcome of electrophilic aromatic substitution chemistry Bromination To brominate an aromatic ring need to generate an electrophilic source of bromine In practice typically add a Lewis acid (e.g. -
Manufacturing of Potassium Permanganate Kmno4 This Is the Most Important and Well Known Salt of Permanganic Acid
Manufacturing of Potassium Permanganate KMnO4 This is the most important and well known salt of permanganic acid. It is prepared from the pyrolusite ore. It is prepared by fusing pyrolusite ore either with KOH or K2CO3 in presence of atmospheric oxygen or any other oxidising agent such as KNO3. The mass turns green with the formation of potassium manganate, K2MnO4. 2MnO2 + 4KOH + O2 →2K2MnO4 + 2H2O 2MnO2 + 2K2CO3 + O2 →2K2MnO4 + 2CO2 The fused mass is extracted with water. The solution is now treated with a current of chlorine or ozone or carbon dioxide to convert manganate into permanganate. 2K2MnO4 + Cl2 → 2KMnO4 + 2KCl 2K2MnO4 + H2O + O3 → 2KMnO4 + 2KOH + O2 3K2MnO4 + 2CO2 → 2KMnO4 + MnO2 + 2K2CO3 Now-a-days, the conversion is done electrolytically. It is electrolysed between iron cathode and nickel anode. Dilute alkali solution is taken in the cathodic compartment and potassium manganate solution is taken in the anodic compartment. Both the compartments are separated by a diaphragm. On passing current, the oxygen evolved at anode oxidises manganate into permanganate. At anode: 2K2MnO4 + H2O + O → 2KMnO4 + 2KOH 2- - - MnO4 → MnO4 + e + - At cathode: 2H + 2e → H2 Properties: It is purple coloured crystalline compound. It is fairly soluble in water. When heated alone or with an alkali, it decomposes evolving oxygen. 2KMnO4 → K2MnO4 + MnO2 + O2 4KMnO4 + 4KOH → 4K2MnO4 + 2H2O + O2 On treatment with conc. H2SO4, it forms manganese heptoxide via permanganyl sulphate which decomposes explosively on heating. 2KMnO4+3H2SO4 → 2KHSO4 + (MnO3)2SO4 + 2H2O (MnO3)2SO4 + H2O → Mn2O7 + H2SO4 Mn2O7 → 2MnO2 + 3/2O2 Potassium permanganate is a powerful oxidising agent. A mixture of sulphur, charcoal and KMnO4 forms an explosive powder.