DOCSLIB.ORG

United States Patent Office Patented Feb

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
United States Patent Office Patented Feb 3,793,355 United States Patent Office Patented Feb. 19, 1974 1. 2 atoms present in complexes according to the present in 3,793,355 vention may be present as: COMPOUNDS OF RUTHENUM Geoffrey Wilkinson, London, England, assignor to John son, Matthey & Co. Limited, London, England No Drawing. Filed Aug. 8, 1972, Ser. No. 278,804 Claims priority, application Great Britain, Aug. 11, 1971, 37,705/71 In C, CO7f 15/00 and with six monovalent anions may therefore form a U.S. C. 260-429 R 7 Claims monovalent cationic species, a neutral species or a mono O Valent anionic species respectively. Preferred embodiments of the present invention are, ABSTRACT OF THE DISCLOSURE therefore: This invention relates to a composition of matter hav ing the general formula (RusO(OCOCH3)6(HO)alt 5 RusC(OCOCH3)6(HO) M1M2M3XAnLLPL3 RusO(OCOCH)6(HO)- where M1, M2 and M3 are the same or different transition metals selected from the second or third series of the Periodic Table; X is oxygen, sulphur, nitrogen, phosphorus or boron; An is anionic element or group and L., L or Li 20 are neutral or anionic ligands. In each of the above, water or triphenylphosphine might be replaced by other ligands, e.g. pyridine or methyl This invention relates to compounds of the second and pyridine. ". third transition series of metals, that is Y-Cd and La 25 Compositions according to the present invention may Hg. More particularly the invention relates to compounds also be in the form of salts derived from the above of those second and third transition series metals which described cations and anions. are members of the platinum group, that is, the members Compositions according to the present invention may of the second and third transition series in Group VIII of be used in electrodeposition especially of ruthenium, for the Periodic Table. The invention is particularly concerned 30 homogeneous catalysis, in aqueous or other fluid media. with oxotriruthenium carboxylate complexes and con The compositions may also be used in the impregnation pounds which may be obtained therefrom. of Substrates for the production of heterogeneous catalysts According to one aspect of the present invention, a and using the methods described in Pat. No. 1,116,943. new composition of matter comprises a complex com The compositions are useful for the catalysts of acidbase pound, cation or anion of the general formula: 35 reactions and for the catalysis of reduction, oxidation, hydrogenation, hydroformylation, carbonylation, iso merization reactions. Where M1, M2 and M3 are the same or different and one By the interaction of commercial hydrated ruthenium or more are transition metals of the second and third 40 trichloride with acetic acid, acetic anhydride mixtures, the series, and preferably platinum group metals; where M', complex Ru(COMe)4C may be obtained; other car M2 and M3 are the same, their formal oxidation states boxylates may be prepared similarly. X-ray crystallog need not be the same, for example, M may have a formal raphy confirms a suggested tetra acetate bridge binuclear oxidation state of --3 whereas M2 and M (atoms of the structure and shows that Ru(COMe)4]+ units are same metal) may have formal oxidation states of +2, 45 linked into chains by Ru-Cl-Rubridges. The complex has other combinations are also possible); X is oxygen, Sul equivalent ruthenium atoms in the mean oxidation state phur, nitrogen, phosphorus or boron, preferably oxygen of -2.5 or, as originally formulated, II, III. (X may not be N when M1, M2 and M8 are all Ir); An The above reaction gives not only [Ru(COMe)]Cl, is anionic element or group such as carboxylate, diethyl but a green solution and it was thought that the latter dithio-carbamate (SCNEta) or Sulphate (a preferred 50 might contain the corresponding neutral dimer. Using carboxylate is acetate), L., L or L, if present may be somewhat different, conditions, namely the interaction of the same or different, and neutral or anionic ligand species ruthenium chloride, acetic acid and sodium acetate in such as HO, pyridine (py), OH, triphenylphosphine ethanol, a green impure material was isolated. This was (PPh3) CO, etc. shown to form adducts with pyridine and triphenylphos One preferred embodiment of the present invention is 55 phine, which were formulated as adducts of the dimer by a complex compound, cation or anion of the general analogy with the well-known adducts of the dimeric tetra formula: bridged acetates of Cril, Cui and Rh. RuO(OCOR) LI In further studies of these materials we have now found that the green acetate is not Ru3(COMe)4 bu an oxo which is an embodiment of the General Formula 60 centered ruthenium (III) basic acetate complex. Molecu lar weight determinations also indicated that the PPh ad MM2M3XAng duct was a trimer and the oxo-centered structure of the latter was proved by X-ray crystallographic study. Hence and in which An is carboxylate of General Formula this complex is Ru3O(COMe)6(PPh3)3, with identical OCOR (e.g. acetate) and L is H2O, py or PPh3. 65 ruthenium atoms in a mean oxidation state of -2%- or The group OCOR represents a generalized carboxylate less correctly using the stock nomenclature with Rur, radical in which R is an aryl or alkyl or substituted aryl Rult, RuTII. or alkyl group. A preferred carboxylate is acetate, in All of the previously known oxo-centered species have which R=CH. the metal atom in the --3 state; the ruthenium acetate The three ruthenium atoms may be in a formally --2 70 system provides the first example of an oxo acetate of a or --3 oxidation state and we believe are at the corners of second or third row element in the Periodic Table (long a triangle with oxygen at its center. The three ruthenium form) and also of reversible redox reactions. - 3,793,355 4 ; : (A) THE -OXOTRIRUTHENIUM (III) with glacial acetic acid. The latter was shown to be ... ....... ... CARBOXYLATES. anionic in methanol and to be reconverted to the aquo (1) Synthesis of oxo carboxylates acetate by water. Hence we have CH3C O The acetate is prepared as described above in an im RusO (COMe) (EO)lt v-- a Rus O (COMe) (COMe)32 pure state; the use of an inert atmosphere is not neces sary, and a reflux time of one hour is sufficient. The Thus it appears that the main product of Mond's reaction crude product contains a considerable excess of sodium is the oxo acetate with unidentate acetate groups replacing acetate, from which it can be separated by a number of water molecules. The other minor green components prob techniques. A preliminary purification is readily achieved ably have both water and acetate coordinated, e.g. the by dialysis in water using a cellophane membrane (Visk 0 neutral RuO (COMe) 6(H2O ) 2CCOMe) l. ing tubing), and the pure acetate has been obtained by (2) Attempts to synthesize the trifluoroacetate chromatography, on Sephade (grade G10). It is best puri fied, however, by recrystallization from methanol-acetone, The synthetic procedure fails for trifluoroacetate, from which it separates as a green powder. Analysis Sup probably due to the much greater strength of CFCOOH, ports the stoichiometry (RuO(COMe)6(H2O)3CO2Me. which possibly prevents the formation of species with The complex is paramagnetic with ueff=1.77 B.M. at 298 Ru-OH-Ru bridges and which, presumably, are inter K. in the solid state (Gouy method). This is consistent mediates in the formation of the Ru3O types. Using neu with an RuTO unit, in which marked spin-spin interac tral or almost neutral solutions gives green or yellow So tion would be expected, via the central oxygen atom. lutions whose electronic spectra are quite different from The complex as formulated would be a unipositive 20 those of the RuO species. cation, but in protonic solvents, ionization of the aquo Other methods have also failed. On refluxing hydrated ligands may occur. High voltage paper electrophoresis ruthenium oxide with trifluoroacetic acid no reaction experiments show that in acidic buffers (pH 2) acetate occurs in two hours whereas acetic acid has almost com oxotriruthenium(III) migrates as a cation, and in alka pletely dissolved the oxide in this time. On prolonged re line-buffers (pH 9), as an anion, the rates of migration in 25 fluxing (several days) or in sealed tubes at 120-160, the two cases being equal. In unbuffered dilute potassium green solutions are obtained but the electronic spectra are chloride solution, cationic, neutral, and anionic species not those of RusO species. are observed. On titration of an aqueous solution of ace The interaction of a carboxylic acid and its anhydride tato oxotriruthenium(III) acetate (pH=6.2) with solu on "RuCin.HO” which produces in addition to tions of sodium hydroxide and hydrochloric acid, a two 30 Ru (COR) 4l Cl proton protonation is observed with pK=4.35. This is in considerable amounts of the green oxo species, fails for the region expected for water coordinated to ruthenium trifluoroacetic acid and there is no apparent reaction, the (III), and is so assigned. This result, together with the trichloride remaining undissolved. electrophoretic behaviour requires that the cationic and 35 Finally, the exchange of acetate and trifluoroacetate anionic species be univalent. The third aquo ligand does also fails. There is no change for up to 48 hours on re not deprotonate in the pH range covered by the tritration fluxing the oxo acetate in trifluoroacetic acid (even pure curve (1-12 pH), but the electronic spectrum of the com acid) as judged by the proton resonance spectrum (al plex undergoes a reversible change in more alkaline solu though the oxoacetate is paramagnetic a methyl resonance tions, which is probably due to the loss of this proton 40 can be observed at T 7.70-see Table 2 which shows the and hence we obtain: proton resonance spectra of ruthenium carboxylates.
Load more

Recommended publications
  • Electrolytic Study of Basic Beryllium Acetate in Carbon Disulphide at 303K, 308K, 313K
    IARJSET ISSN (Online) 2393-8021 ISSN (Print) 2394-1588 International Advanced Research Journal in Science, Engineering and Technology Vol. 7, Issue 11, November 2020 DOI 10.17148/IARJSET.2020.71106 Electrolytic Study of Basic Beryllium Acetate in Carbon disulphide at 303K, 308K, 313K Rajeev Kumar Sharma1, Renu Singhal2 Assistant Professor, Department of Chemistry, D.S. College, Aligarh, U.P. (India)1 Associate Professor, Department of Chemistry, D.S. College, Aligarh, U.P. (India)2 Abstract: The electrolytic study of Basic Beryllium Acetate (B.B.A.) in carbon disulphide were reported at 303K, 308K, 313K, the solute solvent interaction have been carried out by computing various Physico-chemical Acoustic Parameters [Apparent Molal adiabatic compressibility (k), Isentropic compressibility (S), Intermolecular free length (Lf), Specific Acoustic Impedance (Z), Relative Association and Solvation Number (Sn)], these parameters have been evaluated by using ultrasonic velocity, density, viscosity data. The results of these parameters indicates the strength of molecular interaction. Keywords: Molecular Interaction, Electrolytic, viscous behavior of Basic Beryllium acetate. I. INTRODUCTION The Isentropic compressibility of dilute aqueous solution of electrolytes decreases with increasing conc. indicating a strong interaction of the dissolved ion with the alkanols1-7, the non-aqueous solution of electrolytes have drawn the attention of same workers.7-9 Now, we are reporting a study of Ultrasound velocity, density and viscosity measurement at 300C, 350C, 400C have 8 been used to calculate isentropic compressibility (s), Intermolecular Free Lenght (Lf) , Specific Acoustic Impedance 9 10 (Z) , Molar sound velocity (R), Relative association (RA) , Apparent molal adiabatic compressibility (k), Wada 11 0 0 constant (B), Shear’s relaxation time (s) and Solvation numbers (Sn) of B.B.A.
    [Show full text]
  • Methanogenesis Rates in Acetate and Nitrate Amended Anoxic Slurries
    Methanogenesis rates in acetate and nitrate amended anoxic slurries BIOS 35502: Practicum in Environmental Field Biology Patrick Revord Advisor: William West 2011 Abstract With increasing urbanization and land use changes, pollution of lakes and wetland ecosystems is imminent. Any influx of nutrients, anthropogenic or natural, can have dramatic effects on lake gas production and flux. However, the net effect of simultaneous increase of both acetate and nitrate is unknown. Methane (CH4) production was measured in anoxic sediment and water slurries amended with ammonium nitrate (NH4NO3), which has been shown to inhibit methanogenesis, and sodium acetate (CH3COONa or NaOAc), which is known to increase methanogenesis. The addition of acetate significantly increased the methanogenesis rate, but the nitrate amendment had no significant effect. The simultaneous amendment of both acetate and nitrate showed no significant increase in CH4 compared to the control, indicating that the presence of nitrate may have reduced the effect of acetate amendment. Introduction Methane, a greenhouse gas associated with global warming, continues to increase in concentration in our atmosphere. Global yearly flux of methane into the atmosphere is 566 teragrams of CH4 per year, which is more than double pre-industrial yearly flux (Solomon et al. 2007). Increasing urbanization and land-use changes contribute significantly to increased gas levels (Anderson et al. 2010, Vitousek 1994). Nutrients travel from anthropogenic sources such as wastewater treatment facilities, landfills, and agricultural plots into nearby lakes, rivers, and wetlands, causing increased primary productivity in a process known as eutrophication (Vitousek et al. 1997). The increased nutrients and productivity lead to toxic algal blooms that create products such as acetate, H2, and CO2; a nutrient-rich anoxic environment suitable for anaerobic bacteria to produce unnaturally high levels of methane and other greenhouse gases (Davis and Koop 2006, West unpublished data).
    [Show full text]
  • Isoamyl Acetate
    SUMMARY OF DATA FOR CHEMICAL SELECTION Isoamyl Acetate CAS No. 123-92-2 Prepared for NTP by Technical Resources International, Inc Prepared on 11/94 Under NCI Contract No. N01-CP-56019 Table of Contents I. Chemical Identification II. Exposure Information Table 1. Levels of isoamyl acetate reported in foods III. Evidence for Possible Carcinogenic Activity Appendix A: Structural Analogs of Isoamyl Acetate IV. References SUMMARY OF DATA FOR CHEMICAL SELECTION CHEMICAL IDENTIFICATION CAS Registry No.: 123-92-2 Chem. Abstr. Name: 1-Butanol, 3-methyl-, acetate Synonyms: Acetic acid 3-methylbutyl ester; acetic acid, isopentyl ester; AI3-00576; banana oil; isoamyl ethanoate; isopentyl acetate; isopentyl alcohol, acetate; pear oil; 3-methyl-1-butanol acetate; 3-methyl-1-butyl acetate; 3-methylbutyl acetate; 3-methylbutyl ethanoate; i-amyl acetate Structure: Molecular Formula and Molecular Weight: C7H14O2 Mol. Wt.: 130.18 Chemical and Physical Properties: Description: Colorless, flammable liquid with a banana-like odor (ACGIH, 1993). Boiling Point: 142°C (Lide, 1993) Melting Point: -78.5°C (Mark, et al, 1984; Lide, 1993) Solubility: Soluble in water (2000 mg/L at 25°C) (Howard, 1990); soluble in ethanol, diethyl ether, and acetone (Lide, 1993). Vapor 4.5 mm Hg at 20°C (Howard, 1990) Pressure: Refractive 1.4003 (Lide, 1993) Index: Flash Point: closed cup, 33°C; open cup, 38°:C (Budavari, 1989) Density: 0.876 (Lewis, 1993) Reactivity: Thermal decomposition of isoamyl acetate may produce acrid fumes. Contact with strong oxidizing agents, strong acids, and alkaline materials should be avoided (Haarmann & Reimer Corp., 1994). Hazardous decomposition products of isoamyl acetate include CO and CO2 (AESAR/Alfa, 1994) Log 2.13 (Howard, 1990) P(octanol/water partition coefficient): Technical Isoamyl acetate is commercially available as both a natural and synthetic product with a purity Products and range of 95-99+%.
    [Show full text]
  • Bond Distances and Bond Orders in Binuclear Metal Complexes of the First Row Transition Metals Titanium Through Zinc
    Metal-Metal (MM) Bond Distances and Bond Orders in Binuclear Metal Complexes of the First Row Transition Metals Titanium Through Zinc Richard H. Duncan Lyngdoh*,a, Henry F. Schaefer III*,b and R. Bruce King*,b a Department of Chemistry, North-Eastern Hill University, Shillong 793022, India B Centre for Computational Quantum Chemistry, University of Georgia, Athens GA 30602 ABSTRACT: This survey of metal-metal (MM) bond distances in binuclear complexes of the first row 3d-block elements reviews experimental and computational research on a wide range of such systems. The metals surveyed are titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, and zinc, representing the only comprehensive presentation of such results to date. Factors impacting MM bond lengths that are discussed here include (a) n+ the formal MM bond order, (b) size of the metal ion present in the bimetallic core (M2) , (c) the metal oxidation state, (d) effects of ligand basicity, coordination mode and number, and (e) steric effects of bulky ligands. Correlations between experimental and computational findings are examined wherever possible, often yielding good agreement for MM bond lengths. The formal bond order provides a key basis for assessing experimental and computationally derived MM bond lengths. The effects of change in the metal upon MM bond length ranges in binuclear complexes suggest trends for single, double, triple, and quadruple MM bonds which are related to the available information on metal atomic radii. It emerges that while specific factors for a limited range of complexes are found to have their expected impact in many cases, the assessment of the net effect of these factors is challenging.
    [Show full text]
  • NMR Chemical Shifts of Common Laboratory Solvents As Trace Impurities
    7512 J. Org. Chem. 1997, 62, 7512-7515 NMR Chemical Shifts of Common Laboratory Solvents as Trace Impurities Hugo E. Gottlieb,* Vadim Kotlyar, and Abraham Nudelman* Department of Chemistry, Bar-Ilan University, Ramat-Gan 52900, Israel Received June 27, 1997 In the course of the routine use of NMR as an aid for organic chemistry, a day-to-day problem is the identifica- tion of signals deriving from common contaminants (water, solvents, stabilizers, oils) in less-than-analyti- cally-pure samples. This data may be available in the literature, but the time involved in searching for it may be considerable. Another issue is the concentration dependence of chemical shifts (especially 1H); results obtained two or three decades ago usually refer to much Figure 1. Chemical shift of HDO as a function of tempera- more concentrated samples, and run at lower magnetic ture. fields, than today’s practice. 1 13 We therefore decided to collect H and C chemical dependent (vide infra). Also, any potential hydrogen- shifts of what are, in our experience, the most popular bond acceptor will tend to shift the water signal down- “extra peaks” in a variety of commonly used NMR field; this is particularly true for nonpolar solvents. In solvents, in the hope that this will be of assistance to contrast, in e.g. DMSO the water is already strongly the practicing chemist. hydrogen-bonded to the solvent, and solutes have only a negligible effect on its chemical shift. This is also true Experimental Section for D2O; the chemical shift of the residual HDO is very NMR spectra were taken in a Bruker DPX-300 instrument temperature-dependent (vide infra) but, maybe counter- (300.1 and 75.5 MHz for 1H and 13C, respectively).
    [Show full text]
  • Ion Chromatographic Analysis of Disinfectant By-Products
    DCU Ion Chromatographic Analysis of Disinfectant By-Products For the award of D octor of Philosophy Leon Barron School of Chem ical Sciences Student ID: 97311006 V S > N C S R National Centra for Sansor Raiaireh Table of Contents Declaration 11 List of Figures 12 List of Tables 20 List of Abbreviations 22 List of Publications 23 List of Poster Presentations 24 List of Oral Presentations 25 List of Honours and A wards 2 5 Acknowledgements 26 Abstract 28 Chapter 1.0 Literature Review 30 1.0 Background 31 1.1 Current Water Treatment Methods 32 1.1.1 Ozonation 32 1.1.2 Chlorination 35 1.2 Factors Affecting the Formation of Disinfectant By- 36 Products 1.2.1 pH 36 1.2.2 Contact Time 37 1.2.3 Temperature and Season 37 1.2.4 Concentration and Properties of Natural Organic Matter 37 1.2.5 Concentration of Chlorine and Residual Chlorine 38 1.2.6 Concentration of Bromide 38 2 1.3 The Haloacetic Acids 39 1.3.1 Chlorinated Acetic Acids 39 1.3.1.1 Physical and Chemical Properties 39 1.3.1.2 Effects on Laboratory Animals and/or 39 Humans 1.3.2 Brominated Acetic Acids 40 1.3.2.1 Physical Properties 40 1.3.2.2 Effect on Laboratory Animals and/or 41 Humans 1.4 Chromatographic Determination of Haloacetic Acids 42 1.4.1 Introduction to chromatographic theory 42 1.4.2 Band broadening in chromatography 45 1.4.2.1 Multiple path lengths 45 1.4.2.3 Molecular diffusion 46 1.4.2.4 Mass transfer 47 1.4.2.5 The van Deemter equation 47 1.5 Ion Exchange Chromatography 48 1.5.1 The Ion Exchange Process 49 1.5.1.1 Cation Exchange 49 1.5.1.2 Anion Exchange 49 1.5.2 Ion
    [Show full text]
  • A New Take on the Aspirin Synthesis Lab: a Multi-Step Organic Synthesis Laboratory for High School Students
    A new take on the aspirin synthesis lab: A multi-step organic synthesis laboratory for high school students Michael P. Kowalski Rationale The use of the extracts of various plants for the treatment of pain and fever goes back several centuries. A tea made from the leaves or bark of Willow ( Saliaceae ) was found to be especially effective. By the late 19th Century, the active ingredient in these plant extracts, salicylic acid, had been identified. In 1874, the process for the commercial production of salicylic acid was perfected. The use of salicylic acid as an analgesic became widespread. However, side effects, such as gastric bleeding, made long term use of the drug impossible for many patients. In 1895, Felix Hoffman of the Fredrick Bayer Company found a method to acetylate salicylic acid, producing acetyl salicylic acid. This derivative was found to be as effective as salicylic acid as an analgesic but did not have the side effects associated with salicylic acid. The new drug was named “aspirin”, a name inspired by Saint Aspirinius, the patron saint of headaches. The introduction of aspirin marks the beginning of the modern pharmaceutical industry. The mechanism as to how aspirin alleviates pain was not elucidated until the 1970’s, when it was found that aspirin inhibits COX 1 and COX 2, enzymes that catalyze the formation of prostaglandins, substances that cause inflammation (1). The synthesis of aspirin, acetylsalicylic acid, is a standard first year organic chemistry laboratory activity at the college level. In most protocols, salicylic acid is reacted with acetic anhydride producing aspirin and acetic acid by acid catalysis: O OH O O OH O O H2SO4 O CH3 + H3C OH OH H C O CH + 3 3 O The reaction is refluxed for 30 minutes, and then cooled.
    [Show full text]
  • Experiment 1: Synthesis of Acetamides from Aniline and Substituted Anilines
    Chem 216 S11 Notes - Dr. Masato Koreeda Date: May 3, 2011 Topic: __Experiment 1____ page 1 of 2. Experiment 1: Synthesis of Acetamides from Aniline and Substituted Anilines Many of the acetylated [CH3–C(=O)-] derivatives of aromatic amines (aka anilines) and phenols are pharmacologically important compounds. Some of these exhibit distinct analgesic activity. Two of the most representative examples are: H HO O N CH3 O CH3 O HO O acetaminophen (Tylenol) acetylsalicylic acid (Aspirin) ======================================================================= The reaction to be carried out in this experiment is: Acetylation of aniline δ- H3C δ+ O acetic O O anhydride H N CH3 N H (electrophile) HO O CH3 + H O CH3 acetanilide acetic acid aniline (nucleophile) Both aniline and acetic anhydride are somewhat viscous liquids. So, simply mixing them together does not result in the efficient formation of acetanilide. Therefore, a solvent (in this case water) is used to dissolve and evenly disperse two reactants in it. R R R Note: O + N R" N R" N CH R' R' R' 3 CH3 - O O O acetyl group amide The amide N is usually not nucleophilic acetamide because of a significant contribution of this resonance form. Reaction mechanism: δ- H H3C H H H3C δ+ O H N O H O N O CH3 O O N + O O H CH3 O CH3 CH3 pKa ~ -5 3 O CH3 tetrahedral (sp ) intermediate B (including ) O H N CH3 O acetanilide Chem 216 S11 Notes - Dr. Masato Koreeda Date: May 3, 2011 Topic: __Experiment 1____ page 2 of 2. Additional comments on the reaction mechanism: 1.
    [Show full text]
  • Aspirin. an Ab Initio Quantum-Mechanical Study of Conformational Preferences and of Neighboring Group Interactions
    J. Org. Chem. 2001, 66, 771-779 771 Aspirin. An ab Initio Quantum-Mechanical Study of Conformational Preferences and of Neighboring Group Interactions Rainer Glaser Department of Chemistry, University of MissourisColumbia, Columbia, Missouri 65211 [email protected] Received August 15, 2000 The potential energy surface of acetylsalicylic acid, aspirin, has been explored at the RHF/6-31G* and B3LYP/6-31G* levels, and single-point calculations were performed at levels up to B3LYP/ 6-311G**//B3LYP/6-31G*. All conformational isomers have been located, the thermochemical functions have been computed, and relative energies and free enthalpies were determined. The conformational space of aspirin is spanned by three internal coordinates, and these are the carboxylic acid C-O conformation (s-trans preferred by about 7 kcal/mol), the C-COOH conformation (Z preferred unless there are H-bonding opportunities), and the ester C-O conformation (s-trans preferred by about 4 kcal/mol). There are nine aspirin isomers since one of the conformers realizes hydrogen-bonding structure isomerism as well. Neighboring group interactions are discussed with reference to the intrinsic properties of benzoic acid and phenyl acetate. The intrinsic conformational preference energies for benzoic acid and phenyl acetate are not additive. The acid s-trans preference energies differ by as much as 9 kcal/mol depending on the Ph-COOH and ester conformations. Similarly, the E-preference energies about the Ph-COOH bond vary by as much as 6 kcal/mol depending on the ester conformation. The structural discussion suggests an overall ortho repulsion between the functional groups in all aspirin isomers including the intramolecularly hydrogen- bonded isomers.
    [Show full text]
  • Sodium Acetate
    SODIUM ACETATE Prepared at the 18th JECFA (1974), published in NMRS 54B (1975) and in FNP 52 (1992). Metals and arsenic specifications revised at the 59th JECFA (2002). An ADI not limited' was established at the 17th JECFA (1973) SYNONYMS INS No. 262(i) DEFINITION Chemical names Sodium acetate C.A.S. number 127-09-3 Chemical formula C2H3NaO2 · nH2O (n = 0 or 3) Structural formula CH3COONa · nH2O (n = 0 or 3) Formula weight Anhydrous: 82.03 Trihydrate: 136.08 Assay Not less than 98.5% after drying DESCRIPTION Anhydrous: White, odourless, granular, hygroscopic powder Trihydrate: Colourless, transparent crystals or a granular crystalline powder, odourless or with a faint, acetic odour. Effloresces in warm, dry air. FUNCTIONAL USES Buffer CHARACTERISTICS IDENTIFICATION Solubility (Vol. 4) Very soluble in water; soluble in ethanol pH (Vol. 4) 8.0 - 9.5 (1 in 100 soln) Test for sodium (Vol. 4) Passes test Test for acetate (Vol. 4) Passes test Heat test Anhydrous: When heating the sample slowly, it first fuses gradually and boils, and later decomposes evolving an unpleasant odour of acetone. A solution of the residue gives alkaline reaction with litmus paper. Trihydrate: When heating the sample slowly, it liquefies. Then water evaporates, and a powder forms. By heating more strongly, the powder fuses, and becomes lumpy and later decomposes evolving an odour of acetone. A solution of the residue gives alkaline reaction with litmus paper. PURITY Loss on drying (Vol. 4) Anhydrous: Not more than 2.0% (120o, 4 h) Trihydrate: Between 36 and 42% (120o, 4 h) Test for potassium Negative test (Vol.
    [Show full text]
  • Vinyl Acetate
    Vinyl acetate 108-05-4 Hazard Summary Vinyl acetate is primarily used as a monomer in the production of polyvinyl acetate and polyvinyl alcohol. Acute (short-term) inhalation exposure of workers to vinyl acetate has resulted in eye irritation and upper respiratory tract irritation. Chronic (long-term) occupational exposure did not result in any severe adverse effects in workers; some instances of upper respiratory tract irritation, cough, and/or hoarseness were reported. Nasal epithelial lesions and irritation and inflammation of the respiratory tract were observed in mice and rats chronically exposed by inhalation. No information is available on the reproductive, developmental, or carcinogenic effects of vinyl acetate in humans. An increased incidence of nasal cavity tumors has been observed in rats exposed by inhalation. In one drinking water study, an increased incidence of tumors was reported in rats. EPA has not classified vinyl acetate for carcinogenicity. Please Note: The main sources of information for this fact sheet are EPA's Integrated Risk Information System (IRIS) (2), which contains information on inhalation chronic toxicity of vinyl acetate and the RfC, and the Agency for Toxic Substances and Disease Registry's (ATSDR's) Toxicological Profile for Vinyl Acetate. (1) Uses Vinyl acetate is primarily used as a monomer in the production of polyvinyl acetate and polyvinyl alcohol.(1) Vinyl acetate is also used as a raw material in the production of other chemicals, in adhesives, water-based paints, nonwoven textile fibers, textile sizings and finishes, paper coatings, inks, films, and lacquers. (1,2) Sources and Potential Exposure Exposure is most likely to occur in the workplace, where individuals may be occupationally exposed to vinyl acetate via inhalation or dermal contact during its manufacture or use.
    [Show full text]
  • The Background Ion Master List Includes
    REV. A BACKGROUND ION MASTER LIST 1 OF 5 The background ion master list includes: • ESI+ common background ions on page 1 • ESI- common background ions on page 4 • ESI+ common clusters on page 4 • ESI+ common adducts on page 5 • ESI+ ion series on page 5 Table 1: ESI+ common background ions m/z Ion Compound Source 33 (M+H)+ methanol 42 (M+H)+ acetonitrile + 59 (M+NH4) acetonitrile 64 (M+Na)+ acetonitrile 65 (2M+H)+ methanol 74 (M+H)+ dimethylformamide 79 (M+H)+ DMSO 83 (2M+H)+ acetonitrile 85 (M+H)+ d6-DMSO 88 (M+formic acid+H)+ acetonitrile 101 (M+Na)+ DMSO 102 (M+H)+ triethylamine 104/106 (M+Cu)+ acetonitrile 105 (2M+Na)+ acetonitrile 115 (M+dimethyl formamide+H)+ acetonitrile + 120 (M+Na+CH3CN) DMSO 122 (M+H)+ tris (tris(hydroxymethyl)aminomethane) 123 (M+H)+ diisopropylethylamine 130 (M+H)+ diisopropylethylamine + 137 (M+CH3CN+NH4) DMSO 144 (M+H)+ tripropylamine 145/147 (2M+Cu)+ acetonitrile 146 (3M+Na)+ acetonitrile 149 (M+H)+ phthalic anhydride 150 (M+H)+ phenyldiethylamine 153 (M+H)+ 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) 157 (2M+H)+ DMSO 159 (M+Na)+ sodium trifluoroacetate 163 dimethyl phthalate 167 dioctyl phthalate 169 (2M+H)+ d6-DMSO 171 (M+Na)+ phthalic anhydride 179 (2M+Na)+ DMSO 186 (M+H)+ tributylamine 195 (M+H)+ dimethyl phthalate 214 (M+H)+ n-butylbenzenesulfonamide plasticizer © 2010 WATERS COPORATION. ALL RIGHTS RESERVED. REV. A BACKGROUND ION MASTER LIST 2 OF 5 Table 1: ESI+ common background ions (continued) m/z Ion Compound Source 225 (M+H)+ dicyclohexylurea + 231 (M+NH4) n-butyl benzenesulfonamide plasticizer
    [Show full text]