DOCSLIB.ORG

Warwick.Ac.Uk/Lib-Publications

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

A Thesis Submitted for the Degree of PhD at the University of Warwick Permanent WRAP URL: http://wrap.warwick.ac.uk/139891 Copyright and reuse: This thesis is made available online and is protected by original copyright. Please scroll down to view the document itself. Please refer to the repository record for this item for information to help you to cite it. Our policy information is available from the repository home page. For more information, please contact the WRAP Team at: [email protected] warwick.ac.uk/lib-publications 1 AN INVESTIGATION OF SOME REACTIONS OF ALUMINIUM HYDROBORATE A thesis submitted for the degree of Doctor of Philosophy by David L.S. Shaw, B.Sc. The Department of Molecular Sciences^ University of Warwick 1. CONTENTS gage Contents 1 List of Tables 6 List of Figures 7 Acknowledgements 9 Sum m ary 10 1. Introduction 11 Nomenclature 11 Units 12 Hydroborates - Historical 12 Hydroborates - Properties 13 Hydroborates - Structures 17 Hydroborates - Bonding 21 Hydroborates - Vibrational Spectroscopy 24 Hydroborates - Nuclear Magnetic Spectral Properties 27 Aluminium Hydroborate 32 Preparation 32 Synthetic Reactions using Aluminium Hydroborate - Uses 33 Aluminium Hydroborate - Structure and Bonding 34 Aluminium Hydroborate - Properties 38 Physical Properties 38 Aluminium Hydroborate - Reactions 38 Exchange Reactions and Substituted Products 40 Anionic Aluminium Hydroborate Compounds 46 Adducts of Aluminium Hydroborates 47 Vibrational Spectra of Aluminium Hydroborate 50 Nuclear Magnetic Resonance of Aluminium Hydroborates 55 Decomposition of Aluminium Hydroborate - Hydride Aluminium Hydroborates 6-1 I Contents (continued ) Page Aluminium Hydride 63 Aluminium Alkyls 64 Aluminium and Higher Hydroborate Derivatives - Octahydrotriborates - 65 Trialkyl Boranes( Alkyl Diboranes 68 2. Reaction of Aluminium Hydroborate with Alcohols and Thiols and some Compounds containing Alkoxy Groups 69 Reaction ofAluminium Hydroborate with Alcohols 72 1. With M ethanol 72 2. With larger Alcohols 74 The Reaction of Aluminium Hydroborate with Thiols 75 Preparation and attempted Preparation of Alkoxy and Hydroxy Aluminium Hydroborate Species using Exchange Reactions 76 Discussion of the Mechanism of Hydrolysis-type Reaction 78 Properties of Alkoxy and Thloalkyl Aluminium Hydro borates 80 Spectroscopic Properties 81 Nuclear Magnetic Resonance Spectra 85 3. Exchange Reactions of Aluminium Hydroborate with Trialkylboranes 88 Introduction 88 Nuclear Magnetic Resonance Properties of Aluminium Hydroborate/Triethyl borane Mixtures 89 Triethyl borane -Aluminium Hydroborate (1:1 molar ratio) 89 Triethyl borane-Aluminium Hydroborate (5:1 molar ratio) 90 Contents (continued) page Tri«thyl borane-Aluminium Hydroborate (12:1 molar ratio) 90 Triethyl borane-Aluminium Hydroborate (25:1 molar ratio) 90 Trimethyl borane-Aluminium Hydroborate (5:1 molar ratio) 90 Trimethyl borane-CimethylAluminium Hydroborate (5:1 m olar r a tio ) 92 Discussion 92 Infra-red Spectral Data on Aluminium Hydroborate Trialkyl Borane Exchange Reactions 98 Attempted Preparation of B-alkylated Aluminium Hydroborates by a Novel R eaction 102 Conclusion 102 4. Reactions of Aluminium Hydroborate with some Octahydrotriborate and Hydride Species, and their Relevance to Aluminium Hydroborate Decomposition 103 Introduction 103 Dimethyl Aluminium Octahydrotriborate 107 Further Exchange Reactions 130 5. Experimental Details 132 General Techniques 132 A nalytical T echniques 134 Spectroscopic Techniques 136 Preparation of P re c u rs o rs 136 Aluminium Hydroborate 136 Trialkyl Boranes 137 Trimethyl Porane 137 Trlethyl Borane 138 Octahydrotriborate Species: NaB^HgiC^HgO^ )g 138 Contents (continued) gage Other Precursors 140 Alanetrimethylamine 140 Dimethyl Aluminium Hydroborate 140 Tetra-ethyl Diborane 141 4-Methoxy benzyl Alcohol (Anisyl alcohol) 141 Reactions for Chapter 2: 141 Reaction of Aluminium Hydroborate with Methanol 141 Reaction of Aluminium Hydroborate with Aluminium Methoxide 142 Reaction of Aluminium Hydroborate with Aluminium Hydroxide 143 Preparation of Thiomethyl Aluminium bis (Hydro borate) 143 Preparation of Thioethyl Aluminium bis (hydroborate ) 143 Preparation of Thiobenzyl Aluminium bis (hydroborate) 144 Reaction of Aluminium Hydroborate with 2-methyl Propane-2 -thiol 144 Reaction between Aluminium Hydroborate and Tetra- hydrothiophene 145 Reaction of Aluminium Hydroborate with Cyclohexanol 145 Reaction of Aluminium Tetrahydroborate with Anisyl - alcohol (p-methoxy benzyl alcohol )t Benzhydrol (diphenyl methanol) and t-butanol (2-methyl propan-2-ol) 145 Preparation of Methoxy Aluminium bis(hydroborate ) 146 Preparation of Ethoxy Aluminium bis (hydroborate ) 146 Molecular Weight Determination of Ethoxy Aluminium bis (hydroborate ) by a Freezing Point Depression Method 146 5. Contents (continued ) page R eactions for C hapter 3: 148 G eneral 148 Reaction of Tetraethyl Dlborane with Trlethyl Alane 148 Reactions for C hapter 4 : 148 Preparation of Octahydrotr iborate Aluminium bis(hydroborate ) 148 Reaction of Dimethyl Aluminium Octahydrotr iterate with Diborane 149 Reaction of Dimethyl Aluminium Octahydrotr Iterate with Diethyl Ether 150 Reaction of Dimethyl Aluminium Octahydrotr Iterate with T rim ethyl A m ine 150 Reaction of AluminlumHydroterate with Alane Trlmethyl Amine 150 Preparation of Aluminium Hydroborate and Trlmethyl Alane E th e ra tes 150 R eferences 151 6. LI?T OF TABLES page 1.1 Elements known to form simple hydroborates 14 1.2 Physical properties of selected hydroborates 15 1. 3a 52 and Infra-red vibrations of aluminium hydroborate 1.3b 53 2.1 Selected spectral properties of RO and RS A1(BH^>2 compounds 82 3.1 Comparison of the vapour pressure of aluminium hydroborate: 96 trimethyl borane 1 :5 with trimethyl borane 3.2 Measurements of vapour pressure and hydrogen evolution 97 of an A1 (BH^) ^tBEt^ = 5:1 molar mixture 3.3a Infra-red spectral details of excl ge reactions between 99 and A1(BH )„ and BR„ 3.3b 4 '3 100 4.1 Some n.m .r. parameters for Me A1B H 110 2. 3 o page 1.1 Structure of diborane 18 Structure of aluminium hydroborate 18 1.2 Structures of beryllium hydroborate 20 1.3 Bonding in a B-H-B bridge 22 1.4 Simple view of bonding in the diborane bridge system 23 1.5 Infra-red spectrum of diborane 25 1.6 Infra-red spectrum of aluminium hydroborate 26 1.7 General rules for predicting structure types in hydro borate groups 28 1.8 Structures of aluminium hydroborate 35 1.9 M olecular energies of Al(BH4 )g 37 1.10 1H n .m .r. spectrum of AlfBH^)^ In toluene solution 56 1.11 11B n.m .r. spectrum of AlfBH^ in toluene solution 57 2.1 Infra-red spectrum of MeSAliBH^lj 83 2.2 1H n.m .r. spectrum of MeSAKBH^ 86 3.1 Typical ^B n.m .r. spectrum obtained by exchange between A1(BH4 )g and BEt^ 91 3 .2 Infra-red spectrum obtained from mixing of AlEt^ and 101 8. List of Figures (continued ) p ag e 4.1 Infra-red spectrum of Me2AlBgHg 108 4.2a 1^B n.m .r. spectra of pure liquid Me AIB.H 111 and ^ J “ 4.2b 112 11 A 4.3 Bn.m .r. spectra of Me A1B H In toluene d 114 2 o o 4.4 ^~Aln.m.r. spectra of puce Me A1B H at + 23°C 115 2 o o 4.5 Infra-red spectrum of (BH^AlBgHg 120 4.6 n.m .r. spectrum of (BH^AlB^Hg at+ 30°C 122 4.7a 11Bn.m .r. spectrum of (BH4 ^A lB ^H g a f +10° C 123 4.7b 11B n.m .r. spectrum of (BH4)2AlBgHg at -13°C 124 4.7c 11B n.m .r. spectrum of (BH ) A1B-H aX -3 3 ° C 125 4.7d ^B n.m .r .spectrum of (BH4)2AlBgHg at -50°C 126 5.1 Vacuum line 133 5. 2 Diagram of apparatus to carry out hydrolysis of 135 (BH4>2A1B3H8 5.3a Beckmann freezing point apparatus 147 5.3b Flask with n.m .r. tubeside-arm 147 'I r i d 9. ACKNOWLEDGEMENTS The research work reported in this thesis was carried out between October, 1973 and September 1976 in the Department of Molecular Sciences, University of Warwick> Coventry. I should like to express my gratitude to my supervisor, Professor M.G.H. Wallbridge, for his good-humoured encouragement and help throughout. My thanks are due to the technical staff of the Department particularly the long-suffering staff of the glassblowing workshop, Mr. P. Brindley, Mr. E. Burgess and Mr. K. Holden (now at the University of Liverpool), for building and repairing an excellent vacuum line. On a personal note, I should like to thank Mr. D .I. Atkinson for his technical assistance and friendship, and Pauline and my family for their support. Finally I must thank M rs. J.I. McKeand for patiently converting my handwriting into typescript. SUMMARY The reaction of aluminium hydroborate with alcohols and thiols is discussed, and this is extended to cover possible mechanisms for aluminium hydroborate hydrolysis. The course of the reaction was found to be dependent on the structural type of alcohol or thiol used. Substitution of a thio alkyl group for hydroborate led to preparation of the type of compound RSA1(BH^ )^ (where R = methyl, ethyl, benzyl) and properties of these compounds are discussed. Using an exchange reaction of aluminium hydroborate with alkyl borates , corresponding compounds of the type ROAl(BH^>2 (R = m ethyl, ethyl) were prepared, and their properties ascertained. The behaviour of aluminium hydroborate with triethyl and trimethyl borane is considered. This work suggests that there Is an exchange between the terminal hydrogens of the hydroborate groups and the borane alkyl groups, resulting in B-a!kylated aluminium hydroborates. B-alkylated hydroborates are also believed to be formed from a novel reaction between triethyl a lane and tetraethyl diborane. Some chemistry of the octahydrotriborate group linked to aluminium Is also discussed. Starting from dimethyl aluminium octahydrotriborate an exchange reaction with excess aluminium hydroborate yields aluminium octahydrotriborate bis hydroborate. The properties of both compounds are discussed, and the relevance of the latter to aluminium hydroborate decomposition is noted.
Recommended publications
  • Aldrich FT-IR Collection Edition I Library

    Aldrich FT-IR Collection Edition I Library

    Aldrich FT-IR Collection Edition I Library Library Listing – 10,505 spectra This library is the original FT-IR spectral collection from Aldrich. It includes a wide variety of pure chemical compounds found in the Aldrich Handbook of Fine Chemicals. The Aldrich Collection of FT-IR Spectra Edition I library contains spectra of 10,505 pure compounds and is a subset of the Aldrich Collection of FT-IR Spectra Edition II library. All spectra were acquired by Sigma-Aldrich Co. and were processed by Thermo Fisher Scientific. Eight smaller Aldrich Material Specific Sub-Libraries are also available. Aldrich FT-IR Collection Edition I Index Compound Name Index Compound Name 3515 ((1R)-(ENDO,ANTI))-(+)-3- 928 (+)-LIMONENE OXIDE, 97%, BROMOCAMPHOR-8- SULFONIC MIXTURE OF CIS AND TRANS ACID, AMMONIUM SALT 209 (+)-LONGIFOLENE, 98+% 1708 ((1R)-ENDO)-(+)-3- 2283 (+)-MURAMIC ACID HYDRATE, BROMOCAMPHOR, 98% 98% 3516 ((1S)-(ENDO,ANTI))-(-)-3- 2966 (+)-N,N'- BROMOCAMPHOR-8- SULFONIC DIALLYLTARTARDIAMIDE, 99+% ACID, AMMONIUM SALT 2976 (+)-N-ACETYLMURAMIC ACID, 644 ((1S)-ENDO)-(-)-BORNEOL, 99% 97% 9587 (+)-11ALPHA-HYDROXY-17ALPHA- 965 (+)-NOE-LACTOL DIMER, 99+% METHYLTESTOSTERONE 5127 (+)-P-BROMOTETRAMISOLE 9590 (+)-11ALPHA- OXALATE, 99% HYDROXYPROGESTERONE, 95% 661 (+)-P-MENTH-1-EN-9-OL, 97%, 9588 (+)-17-METHYLTESTOSTERONE, MIXTURE OF ISOMERS 99% 730 (+)-PERSEITOL 8681 (+)-2'-DEOXYURIDINE, 99+% 7913 (+)-PILOCARPINE 7591 (+)-2,3-O-ISOPROPYLIDENE-2,3- HYDROCHLORIDE, 99% DIHYDROXY- 1,4- 5844 (+)-RUTIN HYDRATE, 95% BIS(DIPHENYLPHOSPHINO)BUT 9571 (+)-STIGMASTANOL
  • Boranes: Physical & Chemical Properties, Encyclopaedia of Occupational Health and Safety, Jeanne Mager Stellman, Editor-In

    Boranes: Physical & Chemical Properties, Encyclopaedia of Occupational Health and Safety, Jeanne Mager Stellman, Editor-In

    Boranes: Physical & chemical properties, Encyclopaedia of Occupational Health and Safety, Jeanne Mager Stellman, Editor-in-Chief. International Labor Organization, Geneva. 2011. Chemical Name Colour/Form Boiling Point Melting Molecular Solubility in Relative Density Relative Vapour Inflam. Flash Auto CAS-Number (°C) Point (°C) Weight Water (water=1) Vapour Pressure/ Limits Point (°C) Ignition Density (Kpa) Point (°C) (air=1) BORON polymorphic: alpha- 2550 2300 10.81 insol Amorphous, 1.56x 580 3 -5 7440-42-8 rhombohedral form, clear 2.3 g/cm ; 10 red crystals; beta- alpha-- @ 2140 °C rhombohedral form, black; rhombohedral, - alpha-tetragonal form, 2.46 g/cm3; - black, opaque crystals with alpha-- metallic luster; amorphous tetragonal, - form, black or dark brown 2.31 g/cm3; - powder; other crystal beta-rhom- forms known bohedral, - 2.35 g/cm3 BORIC ACID, DISODIUM powder or glass-like 1575 741 201.3 2.56 g/100 g 2.367 SALT plates; white, free-flowing 1330-43-4 crystals; light grey solid BORON OXIDE rhombic crystals; 1860 450 69.6 2.77 g/100 g 1.8 1303-86-2 colourless, (amorphous); semitransparent lumps or 2.46 hard, white crystals (crystalline) BORON TRIBROMIDE colourless liquid 90 -46.0 250.57 reacts 2.6431 8.6 5.3 10294-33-4 @ 18.4 °C/4 °C @ 14 °C BORON TRICHLORIDE 12.5 -107 117.16 1.35 4.03 2.99 Pa 10294-34-5 @ 12 °C/4 @ 12.4 °C BORON TRIFLUORIDE colourless gas -99.9 -126.8 67.82 reacts 3.08g/1.57 l 2.4 10 mm Hg 7637-07-2 @ 4 °C @ -141 °C.
  • Isomorphous Substitution of Aluminium for Silicon in Tobermoritic Structure

    Isomorphous Substitution of Aluminium for Silicon in Tobermoritic Structure

    Isomorphous Substitution of Aluminium for Silicon in Tobermoritic Structure. I. The Mixtures of Different Forms of Silicon Dioxide and of Different Compounds of Aluminium J. PETROVIÖ, V. RUSNÁK and L. ŠTEVULA Institute of Inorganic Chemistry, Slovak Academy of Sciences, Bratislava 9 Received July 2, 1968 The isomorphous substitution of Al(III) for Si(IV) in tobermoritic structure was examined by X-ray phase analysis and DTA. It has been found that the extent of the substitution depends on the materials used. The samples were prepared using different forms of silica-either ^-quartz, quartz-glass, Si02-gel or aerosil. Gibbsite, boehmite, dehydrated kaolinite, kaolinite, corundum and 7-AI2O3 were used as sources of aluminium. The samples were heated in an autoclave at 150, 180 and 200°C for 10, 24 and in some cases for 48 hours. Tobermorite can be synthesized from calcium oxide and silica under hydrothermal conditions. Up to temperatures of about 110°C it is stable, at higher temperatures and under hydrothermal conditions it is formed as an unstable compound. When the reaction is allowed to proceed for a longer time, or when it takes place at higher tem­ perature, another stable calcium hydrosilicate arises. At lower temperature a calcium hydrosilicate with tobermoritic structure is formed. It has been found that tobermori­ te is produced on autoclaving building materials containing lime and some materials with high SÍO2 content. It is also formed from anhydrous dicalcium silicates in the course of setting of cement. Under different conditions, compounds with tobermoritic structure arise which, however, differ in the amount or lime and water in the molecu­ le, as well as in the arrangement of the structure — e.g.
  • 3-Substituted-6-Aryl Pyridines As Ligands of C5a Receptors

    3-Substituted-6-Aryl Pyridines As Ligands of C5a Receptors

    (19) & (11) EP 1 565 452 B1 (12) EUROPEAN PATENT SPECIFICATION (45) Date of publication and mention (51) Int Cl.: of the grant of the patent: C07D 401/06 (2006.01) C07D 405/12 (2006.01) 04.04.2012 Bulletin 2012/14 C07D 413/04 (2006.01) (21) Application number: 03768799.3 (86) International application number: PCT/US2003/035694 (22) Date of filing: 07.11.2003 (87) International publication number: WO 2004/043925 (27.05.2004 Gazette 2004/22) (54) 3-SUBSTITUTED-6-ARYL PYRIDINES AS LIGANDS OF C5A RECEPTORS 3-SUBSTITUIERTE-6-ARYL- PYRIDIN DERIVATE ALS LIGANDEN FÜR C5A-REZEPTOREN 6-ARYL PYRIDINES SUBSTITUEES EN POSITION 3 EN TANT QUE LIGANDS DES RECEPTEURS C5A (84) Designated Contracting States: (74) Representative: Adam, Holger et al AT BE BG CH CY CZ DE DK EE ES FI FR GB GR Kraus & Weisert HU IE IT LI LU MC NL PT RO SE SI SK TR Patent- und Rechtsanwälte Thomas-Wimmer-Ring 15 (30) Priority: 08.11.2002 US 425281 P 80539 München (DE) (43) Date of publication of application: (56) References cited: 24.08.2005 Bulletin 2005/34 EP-A- 0 338 504 EP-A- 1 308 438 WO-A-02/49993 WO-A-99/31062 (73) Proprietor: Novartis International Pharmaceutical Ltd. • PATENT ABSTRACTS OF JAPAN vol. 2000, no. Hamilton (BM) 11, 3 January 2001 (2001-01-03) & JP 2000 226372 A (NIPPON SODA CO LTD), 15 August 2000 (72) Inventors: (2000-08-15) • HUTCHISON, Alan • ROBL J A ET AL: "PHOSPHORUS-CONTAINING Madison, CT 06443 (US) INHIBITORS OF HMG-COA REDUCTASE.
  • Absence of Skin Sensitivity to Oxides of Aluminium, Silicon, Titanium Or Zirconium in Patients With

    Absence of Skin Sensitivity to Oxides of Aluminium, Silicon, Titanium Or Zirconium in Patients With

    Gut1996;39:231-233 231 Absence of skin sensitivity to oxides of aluminium, Silicon, titanium or zirconium in patients with Crohn's disease Gut: first published as 10.1136/gut.39.2.231 on 1 August 1996. Downloaded from J C W Lee, S Halpem, D G Lowe, A Forbes, J E Lennard-Jones Abstract obstructive lymphadenopathy. It has been Background-Some metallic compounds, proposed that this is caused by fibrosis of the especially of zirconium, can cause cell afferent lymphatics as a result of absorption of mediated granulomatous inflammation of microparticles of silica and alumino-silicates the skin. Pigment granules containing through the skin where people walk barefoot compounds of aluminium, silicon, and on certain types of soil. Particles containing titanium have been observed within silica, titanium, and aluminium are present in macrophages in the wall of the small microgranulomata within inguinal lymph intestine in health and in Crohn's disease. nodes of sufferers.6 Granulomata also develop Zirconium compounds can be ingested in in response to intradermal injection ofcolloidal toothpaste. silica in healthy subjects but these are foreign Aim-To determine in a pilot study if body granulomata and are clearly distinguish- granulomatous sensitivity can be detected able from the cell mediated response to small to compounds of these metals or silicon quantities of zirconium lactate.7 after injection into the skin of patients As metals and minerals are ubiquitous in the with Crohn's disease. community, a hypersensitivity to these sub- Subjects-Eight patients with Crohn's stances in some people rather than a direct disease known to have had granulomata in toxic effect is the most probable pathogenetic the intestine and not currently treated mechanism by which they may contribute to with corticosteroids, and two healthy disease.
  • Applications of Boronic Acids in Organic Synthesis

    Applications of Boronic Acids in Organic Synthesis

    Applications of Boronic Acids in Organic Synthesis A dissertation presented by Pavel Starkov in partial fulfilment of the requirements for the award of the degree of DOCTOR OF PHILOSOPHY at UNIVERSITY COLLEGE LONDON Department of Chemistry Christopher Ingold Laboratories University College London 20 Gordon Street WC1H 0AJ London Declaration This dissertation is the result of my own work. Where information has been derived from other sources it has been clearly indicated so and acknowledged accordingly. /Pavel Starkov/ ii Abstract This thesis describes progress on the application of boronic acids and borate esters as catalysts and reagents in synthetic organic synthesis, focusing on two areas: one-pot enolate formation/aldol reactions and amide bond formation. Chapter 1 introduces the reader to boronic acids and derivatives thereof, their methods of preparation and their use in synthetic organic chemistry as reactants, reagents and catalysts. Chapter 2 covers current chemical methods and cellular alternatives for amide bond formation. Here, we also discuss our use of boron reagents for the activation of carboxylic acids as well as amides. Chapter 3 introduces a new concept in catalytic aldol reactions, i.e. an alternative strategy to access boron enolates in situ. The work covers successful demonstration of the feasibility of such an approach on an intramolecular system. A novel variation of aerobic Chan–Evans– Lam coupling, an intramolecular coupling of an aliphatic alcohol with a boronic acid using catalytic copper, is also introduced Chapter 4 builds on our observations on gold catalysis and especially that in relation to electrophilic halogenations. Chapter 5 contains full details of the experimental procedures.
  • Sintering of Aluminum Powder with Microwave

    Sintering of Aluminum Powder with Microwave

    ISSN (Online) 2393-8021 ISSN (Print) 2394-1588 IARJSET International Advanced Research Journal in Science, Engineering and Technology Vol. 6, Issue 9, September 2019 Sintering of Aluminum Powder with Microwave Imad ul Iman Chikkodi1 Student, Electronics & Communication, KLE Dr. M.S. Sheshgiri College of Engineering & Technology, Belgaum, India1 Abstract: Sintering or frittage is the process of compacting and forming a solid mass of material by heat or pressure without melting it to the point of liquefaction. Sintering happens naturally in mineral deposits or as a manufacturing process used with metals, ceramics, plastics, and other materials. Sintering happens naturally in mineral deposits or as a manufacturing process used with metals, ceramics, plastics, and other materials. The atoms in the materials diffuse across the boundaries of the particles, fusing the particles together and creating one solid piece. Because the sintering temperature does not have to reach the melting point of the material, sintering is often chosen as the shaping process for materials with extremely high melting points such as tungsten and molybdenum. The study of sintering in metallurgy powder-related processes is known as powder metallurgy. An example of sintering can be observed when ice cubes in a glass of water adhere to each other, which is driven by the temperature difference between the water and the ice. Examples of pressure-driven sintering are the compacting of snowfall to a glacier, or the forming of a hard snowball by pressing loose snow together. Keywords: Sintering, Aluminium, Silicone Carbide, Microwave Sintering I. INTRODUCTION Most, if not all, metals can be sintered. This applies especially to pure metals produced in vacuum which suffer no surface contamination.
  • Boronic Acids

    Boronic Acids

    Boronic Acids Boronic Acids www.alfa.com INCLUDING: • Boronic Esters • Oxazaborolidine Reagents • Coupling and Hydroboration Catalysts • Phosphine Ligands • Borylation Reagents www.alfa.com Where Science Meets Service Quality Boronic Acids from Alfa Aesar Alfa Aesar is known worldwide for a variety of chemical compounds used in research and development. Recognized for purity and quality, our products and brands are backed by technical and sales teams dedicated to providing you the best service possible. In this catalog, you will find details on our line of boronic acids, esters and related compounds, which are manufactured to the same exacting standards as our full offering of over 33,000 products. Also included in this catalog is a 28-page introduction to boronic acids, their properties and applications. This catalog contains only a selection of our wide range of chemicals and materials. Also included is a selection of novel coupling catalysts and ligands. Many more products, including high purity metals, analytical products, and labware are available in our main catalog or online at www.alfa.com. Table of Contents About Us _____________________________________________________________________________ II How to Order/General Information ____________________________________________________ III Introduction __________________________________________________________________________ 1 Alkenylboronic acids and esters _____________________________________________________ 29 Alkylboronic acids and esters ________________________________________________________
  • Chemistry; Metallurgy

    Chemistry; Metallurgy

    C01F SECTION C --- CHEMISTRY; METALLURGY C01 INORGANIC CHEMISTRY XXXX C01F C01F XXXX C01F COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS (metal hydrides C01B 6/00; salts of oxyacids of halogens C01B 11/00; peroxides, salts of peroxyacids C01B 15/00; sulfides or polysulfides of magnesium, calcium, strontium, or barium C01B 17/42; thiosulfates, dithionites, polythionates C01B 17/64; compounds containing selenium or tellurium C01B 19/00; binary compounds of nitrogen with metals C01B 21/06; azides C01B 21/08; metal amides C01B 21/092; nitrites C01B 21/50; phosphides C01B 25/08; salts of oxyacids of phosphorus C01B 25/16; carbides C01B 31/30; compounds containing silicon C01B 33/00; compounds containing boron C01B 35/00; compounds having molecular sieve properties but not having base-exchange properties C01B 37/00; compounds having molecular sieve and base-exchange properties, e.g. crystalline zeolites, C01B 39/00; cyanides C01C 3/08; salts of cyanic acid C01C 3/14; salts of cyanamide C01C 3/16; thiocyanates C01C 3/20; fermentation or enzyme-using processes for the preparation of elements or inorganic compounds except carbon dioxide C12P 3/00; obtaining metal compounds from mixtures, e.g. ores, which are intermediate compounds in a metallurgical process for obtaining a free metal C22B; production of non-metallic elements or inorganic compounds by electrolysis or electrophoresis C25B) (1) Attention is drawn to Note (1) after class C01, which defines the last place priority rule applied in this class, i.e. in the range of subclasses C01B C01G and within these subclasses.
  • 12Cl23h2o, a New Gibbsite-Based Hydrotalcite Supergroup

    12Cl23h2o, a New Gibbsite-Based Hydrotalcite Supergroup

    minerals Article Dritsite, Li2Al4(OH)12Cl2·3H2O, a New Gibbsite-Based Hydrotalcite Supergroup Mineral Elena S. Zhitova 1,2,* , Igor V. Pekov 3, Ilya I. Chaikovskiy 4, Elena P. Chirkova 4, Vasiliy O. Yapaskurt 3, Yana V. Bychkova 3, Dmitry I. Belakovskiy 5, Nikita V. Chukanov 6, Natalia V. Zubkova 3, Sergey V. Krivovichev 1,7 and Vladimir N. Bocharov 8 1 Department of Crystallography, St. Petersburg State University, Universitetskaya nab. 7/9, St. Petersburg 199034, Russia 2 Laboratory of Mineralogy, Institute of Volcanology and Seismology, Russian Academy of Sciences, Bulvar Piypa 9, Petropavlovsk-Kamchatsky 683006, Russia 3 Faculty of Geology, Moscow State University, Vorobievy Gory, Moscow 119991, Russia 4 Mining Institute, Ural Branch of the Russian Academy of Sciences, Sibirskaya str., 78a, Perm 614007, Russia 5 Fersman Mineralogical Museum, Russian Academy of Sciences, Leninsky Prospekt 18-2, Moscow 119071, Russia 6 Institute of Problems of Chemical Physics, Russian Academy of Sciences, Akad. Semenova 1, Chernogolovka, Moscow Region 142432, Russia 7 Nanomaterials Research Centre, Kola Science Centre, Russian Academy of Sciences, Fersman Street 14, Apatity 184209, Russia 8 Resource Center Geomodel, St. Petersburg State University, Universitetskaya nab. 7/9, St. Petersburg 199034, Russia * Correspondence: [email protected]; Tel.: +7-924-587-51-91 Received: 2 August 2019; Accepted: 14 August 2019; Published: 17 August 2019 Abstract: Dritsite, ideally Li Al (OH) Cl 3H O, is a new hydrotalcite supergroup mineral formed 2 4 12 2· 2 as a result of diagenesis in the halite carnallite rock of the Verkhnekamskoe salt deposit, Perm Krai, − Russia. Dritsite forms single lamellar or tabular hexagonal crystals up to 0.25 mm across.
  • Compounds of the Metals Beryllium, Magnesium

    Compounds of the Metals Beryllium, Magnesium

    C01F COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS (metal hydrides [N: monoborane, diborane or addition complexes thereof] C01B6/00; salts of oxyacids of halogens C01B11/00; peroxides, salts of peroxyacids C01B15/00; sulfides or polysulfides of magnesium, calcium, strontium, or barium C01B17/42; thiosulfates, dithionites, polythionates C01B17/64; compounds containing selenium or tellurium C01B19/00; binary compounds of nitrogen with metals C01B21/06; azides C01B21/08; [N: compounds other than ammonia or cyanogen containing nitrogen and non-metals and optionally metals C01B21/082; amides or imides of silicon C01B21/087]; metal [N: imides or] amides C01B21/092, [N: C01B21/0923]; nitrites C01B21/50; [N: compounds of noble gases C01B23/0005]; phosphides C01B25/08; salts of oxyacids of phosphorus C01B25/16; carbides C01B31/30; compounds containing silicon C01B33/00; compounds containing boron C01B35/00; compounds having molecular sieve properties but not having base-exchange properties C01B37/00; compounds having molecular sieve and base-exchange properties, e.g. crystalline zeolites, C01B39/00;cyanides C01C3/08; salts of cyanic acid C01C3/14; salts of cyanamide C01C3/16; thiocyanates C01C3/20; [N: double sulfates of magnesium with sodium or potassium C01D5/12; with other alkali metals C01D15/00, C01D17/00]) Definition statement This subclass/group covers: All compounds of Be,Mg,Al,Ca,Sr,Ba,Ra,Th or rare earth metals except those compounds which are classified in C01G because of application of the last appropriate place rule. So, in principle does this subclass comprise all Al-compounds with elements as such being part of C01B-C01D, e.g.
  • Nicolet Vapor Phase

    Nicolet Vapor Phase

    Nicolet Vapor Phase Library Listing – 8,654 spectra This library is one the most comprehensive collections of vapor phase FT-IR spectra. It is an invaluable tool for scientist involved in investigations on gas phase materials. The Nicolet Vapor Phase Library contains 8654 FT-IR spectra of compounds measured in gas phase. Most spectra were acquired by the Sigma-Aldrich Co. using product samples. Additional spectra were collected by Hannover University, University of Wurzburg and Thermo Fisher Scientific applications scientists. Spectra were collected using sampling techniques including heated or room temperature gas cell or a heated light-pipe connected to the outlet of a gas chromatograph. Nicolet Vapor Phase Index Compound Name Index Compound Name 8402 ((1- 5457 (-)-8-Phenylmenthol; (-)-(1R,2S,5R)-5- Ethoxycyclopropyl)oxy)trimethylsilane Methyl-2-(2-phenyl-2-propyl)cyc 4408 (+)-1,3-Diphenylbutane 1095 (-)-Carveol, mixture of isomers; p- 4861 (+)-1-Bromo-2,4-diphenylbutane Mentha-6,8-dien-2-ol 2406 (+)-3-(Heptafluorobutyryl)camphor 3628 (-)-Diisopropyl D-tartrate 2405 (+)-3-(Trifluoroacetyl)camphor 1427 (-)-Limonene oxide, cis + trans; (-)-1,2- 281 (+)-3R-Isolimonene, trans-; (1R,4R)- Epoxy-4-isopropenyl-1-methyl (+)-p-Mentha-2,8-diene 1084 (-)-Menthol; [1R-(1a,2b,5a)]-(-)-2- 289 (+)-Camphene; 2,2-Dimethyl-3- Isopropyl-5-methylcyclohexanol methylenebicyclo[2.2.1]heptane 2750 (-)-Menthoxyacetic acid 3627 (+)-Diisopropyl L-tartrate 1096 (-)-Myrtanol, cis-; (1S,2R)-6,6- 2398 (+)-Fenchone; (+)-1,3,3- Dimethylbicyclo[3.1.1]heptane-2-metha