Prakash Vita-September 2018
Total Page：16
File Type：pdf, Size：1020Kb
Load more
Recommended publications
-
Acidity, Basicity, and Pka 8 Connections
Acidity, basicity, and pKa 8 Connections Building on: Arriving at: Looking forward to: • Conjugation and molecular stability • Why some molecules are acidic and • Acid and base catalysis in carbonyl ch7 others basic reactions ch12 & ch14 • Curly arrows represent delocalization • Why some acids are strong and others • The role of catalysts in organic and mechanisms ch5 weak mechanisms ch13 • How orbitals overlap to form • Why some bases are strong and others • Making reactions selective using conjugated systems ch4 weak acids and bases ch24 • Estimating acidity and basicity using pH and pKa • Structure and equilibria in proton- transfer reactions • Which protons in more complex molecules are more acidic • Which lone pairs in more complex molecules are more basic • Quantitative acid/base ideas affecting reactions and solubility • Effects of quantitative acid/base ideas on medicine design Note from the authors to all readers This chapter contains physical data and mathematical material that some readers may find daunting. Organic chemistry students come from many different backgrounds since organic chemistry occu- pies a middle ground between the physical and the biological sciences. We hope that those from a more physical background will enjoy the material as it is. If you are one of those, you should work your way through the entire chapter. If you come from a more biological background, especially if you have done little maths at school, you may lose the essence of the chapter in a struggle to under- stand the equations. We have therefore picked out the more mathematical parts in boxes and you should abandon these parts if you find them too alien. -
2004 DOE/BES Analysis Program Contractors' Meeting
2004 DOE/BES Analysis Program Contractors’ Meeting Annapolis, Maryland February 12 – 14, 2004 Sponsored by The U.S. Department of Energy Office of Basic Energy Sciences Workshop Chair: John Miller 2004 DOE/BES Analysis Program Contractors’ Meeting Program and Abstracts Department of Energy Office of Science Office of Basic Energy Sciences Chemical Sciences, Geosciences and Biosciences Division FOREWORD This abstract booklet provides a record of the 2004 U.S. Department of Energy, Office of Basic Energy Sciences, Analysis Program Contractors’ Meeting. This group of scientists last met as part of the larger Separations and Analysis Program Contractors’ Meeting held in San Diego April 5-7, 2001. The agenda and abstracts of that meeting may be found on the web at http://www.sc.doe.gov/bes/chm/Publications/publications.html. There is wide agreement that a gathering of researchers with common interests and sponsorship provides a fruitful environment for exchange of research results, research techniques, and research opportunities. The primary means of communicating research achievements and perspectives at this meeting is oral presentations, formal discussion periods and informal breaks and meals. The agenda has been organized so that papers in related disciplines – such as mass spectrometry or optical spectroscopy – are loosely clustered together. I am pleased to have the privilege of organizing this meeting and of serving as the program manager of this world-class research program. In carrying out these tasks, I learn from the achievements, and share the excitement, of the research of the many sponsored scientists and students whose names appear on the papers in the following pages. -
Trifluoromethane)
SAFETY DATA SHEET Halocarbon R-23 (Trifluoromethane) Section 1. Identification GHS product identifier : Halocarbon R-23 (Trifluoromethane) Chemical name : trifluoromethane Other means of : Fluoroform; Arcton 1; Fluoryl; Freon F-23; Freon 23; Genetron 23; Methyl trifluoride; R identification 23; Trifluoromethane; CHF3; Arcton; Halocarbon 23; UN 1984; Carbon trifluoride; Genetron HFC23; Propellant 23; Refrigerant 23 Product type : Liquefied gas Product use : Synthetic/Analytical chemistry. Synonym : Fluoroform; Arcton 1; Fluoryl; Freon F-23; Freon 23; Genetron 23; Methyl trifluoride; R 23; Trifluoromethane; CHF3; Arcton; Halocarbon 23; UN 1984; Carbon trifluoride; Genetron HFC23; Propellant 23; Refrigerant 23 SDS # : 001078 Supplier's details : Airgas USA, LLC and its affiliates 259 North Radnor-Chester Road Suite 100 Radnor, PA 19087-5283 1-610-687-5253 24-hour telephone : 1-866-734-3438 Section 2. Hazards identification OSHA/HCS status : This material is considered hazardous by the OSHA Hazard Communication Standard (29 CFR 1910.1200). Classification of the : GASES UNDER PRESSURE - Liquefied gas substance or mixture GHS label elements Hazard pictograms : Signal word : Warning Hazard statements : Contains gas under pressure; may explode if heated. May cause frostbite. May displace oxygen and cause rapid suffocation. Precautionary statements General : Read and follow all Safety Data Sheets (SDS’S) before use. Read label before use. Keep out of reach of children. If medical advice is needed, have product container or label at hand. Close valve after each use and when empty. Use equipment rated for cylinder pressure. Do not open valve until connected to equipment prepared for use. Use a back flow preventative device in the piping. Use only equipment of compatible materials of construction. -
New and Improved Infrared Absorption Cross Sections for Chlorodifluoromethane (HCFC-22)
Atmos. Meas. Tech., 9, 2593–2601, 2016 www.atmos-meas-tech.net/9/2593/2016/ doi:10.5194/amt-9-2593-2016 © Author(s) 2016. CC Attribution 3.0 License. New and improved infrared absorption cross sections for chlorodifluoromethane (HCFC-22) Jeremy J. Harrison1,2 1Department of Physics and Astronomy, University of Leicester, University Road, Leicester, LE1 7RH, UK 2National Centre for Earth Observation, University of Leicester, University Road, Leicester, LE1 7RH, UK Correspondence to: Jeremy J. Harrison ([email protected]) Received: 10 December 2015 – Published in Atmos. Meas. Tech. Discuss.: 18 January 2016 Revised: 3 May 2016 – Accepted: 6 May 2016 – Published: 17 June 2016 Abstract. The most widely used hydrochlorofluorocarbon 1 Introduction (HCFC) commercially since the 1930s has been chloro- difluoromethane, or HCFC-22, which has the undesirable The consumer appetite for safe household refrigeration led effect of depleting stratospheric ozone. As this molecule to the commercialisation in the 1930s of dichlorodifluo- is currently being phased out under the Montreal Pro- romethane, or CFC-12, a non-flammable and non-toxic re- tocol, monitoring its concentration profiles using infrared frigerant (Myers, 2007). Within the next few decades, other sounders crucially requires accurate laboratory spectroscopic chemically related refrigerants were additionally commer- data. This work describes new high-resolution infrared ab- cialised, including chlorodifluoromethane, or a hydrochlo- sorption cross sections of chlorodifluoromethane over the rofluorocarbon known as HCFC-22, which found use in a spectral range 730–1380 cm−1, determined from spectra wide array of applications such as air conditioners, chillers, recorded using a high-resolution Fourier transform spectrom- and refrigeration for food retail and industrial processes. -
Fluoroform (CHF3)
SYNLETT0936-52141437-2096 © Georg Thieme Verlag Stuttgart · New York 2015, 26, 1911–1912 1911 spotlight Syn lett S. Kyasa Spotlight Fluoroform (CHF3) ShivaKumar Kyasa ShivaKumar Kyasa was born in Telangana state, India, in 1978. After completing a B.Sc. (chemis- try, biology) and a M.Sc. (medicinal chemistry) Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE 68588-0304, USA from Osmania University, he worked at Dr. Red- [email protected] dy’s Laboratories, Ltd., Hyderabad, India. He is currently pursuing a Ph.D. in chemistry at the Published online: 11.06.2015 University of Nebraska–Lincoln, USA under the DOI: 10.1055/s-0034-1380924; Art ID: st-2015-v0519-v supervision of Prof. Patrick H. Dussault. His re- search focuses on C–O bond formation and syn- thesis of functionalized ethers using peroxide oxygen as an electrophile. Introduction with Lewis bases (most commonly catalytic fluoride) to af- ford pentavalent silicon species as nucleophiles has enabled Fluoroform, which is generated in ~20 kilotons/year trifluoromethylation of a number of electrophiles.4 The tri- as a side product of Teflon manufacture,1,2 is a low-boiling fluoromethyl group has great importance in medicinal, ag- (-82 °C), non-toxic and non-ozone-depleting gas.1,3 Howev- rochemical and materials science.5 This spotlight describes er, fluoroform is a potent greenhouse agent and there is recently reported methods for tri- and difluoromethylation great interest in methods for use of the gas as a synthetic based upon fluoroform. reagent. The direct use of trifluoromethyl anion as a nucleo- phile has been challenging due to facile α-elimination to CF3 CF2 + F fluoride and difluorocarbene (Scheme 1). -
Synthetic Applications of Dienes and Polyenes, Excluding Cycloadditions
The Chemistry of Dienes and Polyenes. Volume 2 Edited by Zvi Rappoport Copyright 2000 John Wiley & Sons, Ltd. ISBN: 0-471-72054-2 CHAPTER 9 Synthetic applications of dienes and polyenes, excluding cycloadditions NANETTE WACHTER-JURCSAK Department of Chemistry, Biochemistry and Natural Science, Hofstra University, Hempstead, New York 11549-1090, USA Fax: (516) 463-6394; e-mail: [email protected] and KIMBERLY A. CONLON Department of Pharmacological Sciences, School of Medicine, State University of New York at Stony Brook, Stony Brook, New York 11794-8651, USA Fax: (516) 444-3218; e-mail: [email protected] I. INTRODUCTION ..................................... 693 II. ADDITION REACTIONS ............................... 694 III. OXIDATION REACTIONS ............................... 700 IV. COUPLING REACTIONS ............................... 710 A. Wittig Reactions of Dienes and Polyenes .................... 711 B. Coupling Promoted by Organometallic Reagents ............... 712 V. DIMERIZATION REACTIONS ............................ 718 VI. PREPARATION OF METAL–POLYENE COMPLEXES ........... 720 VII. REARRANGEMENTS .................................. 722 A. Cope Rearrangement ................................. 722 B. Claisen Rearrangement ............................... 728 VIII. REFERENCES ....................................... 736 I. INTRODUCTION The reactivity of polyenes is influenced by their substituents, and whether or not the multiple double bonds of the unsaturated hydrocarbon are conjugated or isolated from 693 694 Nanette Wachter-Jurcsak and Kimberly A. Conlon one another. The -system of a polyene may be fully conjugated, or there may be one or more pairs of conjugated double bonds isolated from the other -bonds in the molecule, or, alternatively, each of the carbon–carbon double bonds in the polyene may be isolated from one another. Conjugated -systems react differently with electrophiles than isolated double bonds. Addition of hydrogen to isolated double bonds has been previously discussed in this series and will not be addressed here1. -
SAFETY DATA SHEET Halocarbon R-503
SAFETY DATA SHEET Halocarbon R-503 Section 1. Identification GHS product identifier : Halocarbon R-503 Other means of : Not available. identification Product type : Liquefied gas Product use : Synthetic/Analytical chemistry. SDS # : 007306 Supplier's details : Airgas USA, LLC and its affiliates 259 North Radnor-Chester Road Suite 100 Radnor, PA 19087-5283 1-610-687-5253 24-hour telephone : 1-866-734-3438 Section 2. Hazards identification OSHA/HCS status : This material is considered hazardous by the OSHA Hazard Communication Standard (29 CFR 1910.1200). Classification of the : GASES UNDER PRESSURE - Liquefied gas substance or mixture HAZARDOUS TO THE OZONE LAYER - Category 1 GHS label elements Hazard pictograms : Signal word : Warning Hazard statements : Contains gas under pressure; may explode if heated. May cause frostbite. May displace oxygen and cause rapid suffocation. Harms public health and the environment by destroying ozone in the upper atmosphere. Precautionary statements General : Read and follow all Safety Data Sheets (SDS’S) before use. Read label before use. Keep out of reach of children. If medical advice is needed, have product container or label at hand. Close valve after each use and when empty. Use equipment rated for cylinder pressure. Do not open valve until connected to equipment prepared for use. Use a back flow preventative device in the piping. Use only equipment of compatible materials of construction. Always keep container in upright position. Prevention : Not applicable. Response : Not applicable. Storage : Protect from sunlight. Store in a well-ventilated place. Disposal : Refer to manufacturer or supplier for information on recovery or recycling. Hazards not otherwise : Liquid can cause burns similar to frostbite. -
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 -
Curriculum Vitae
1 CURRICULUM VITAE Robert Bau Born: February 10, 1944, Shanghai, China (naturalized U.S. citizen, 1974) Education: B.Sc., University of Hong Kong, June, 1964 Ph.D., University of California at Los Angeles, March, 1968 ` Postdoctoral Research Fellow, Harvard University, 1968-69 Positions Held Since Ph.D. Degree: 1977-present Professor of Chemistry, University of Southern California 1974-77 Associate Professor of Chemistry, University of Southern California 1969-74 Assistant Professor of Chemistry, University of Southern California Awards and Honors: Fellow of the Alfred P. Sloan Foundation, 1974-76 NIH Research Career Development Awardee, 1975-80 Recipient of USC Associates Award for Excellence in Teaching, 1974 Recipient of USC Associates Award for Excellence in Research, 1979 Fellow of the American Association for the Advancement of Science, 1982 Recipient of the Alexander van Humboldt Foundation, U.S. Senior Scientist Award, 1985 Visiting Professor of Chemistry, University of Grenoble, France, March-June, 1989 President, American Crystallographic Association, 2006 Research Interests: X-ray and Neutron Diffraction Studies of Covalent Metal Hydride Compounds Neutron Diffraction Studies on Molecules Having Chiral Methylene Groups (Molecules of the type CHDRR') Neutron Diffraction Studies of Small Proteins 2 PUBLICATION LIST Professor Robert Bau Department of Chemistry University of Southern California Los Angeles, California 90089-0744 1. "The Crystal Structure of HRe2Mn(CO)14. A Neutral, 'Electron Deficient', Polynuclear Carbonyl Hydride", H.D. Kaesz, R. Bau, and M.R. Churchill, J. Am. Chem. Soc., 89, 2775 (1967). 2. "Spectroscopic Studies of Isotopically Substituted Metal Carbonyls. I. Vibrational Analysis of Metal Pentacarbonyl Halides", H.D. Kaesz, R. Bau, D. Hendrickson and J.M. -
Los Premios Nobel De Química
Los premios Nobel de Química MATERIAL RECOPILADO POR: DULCE MARÍA DE ANDRÉS CABRERIZO Los premios Nobel de Química El campo de la Química que más premios ha recibido es el de la Quí- mica Orgánica. Frederick Sanger es el único laurea- do que ganó el premio en dos oca- siones, en 1958 y 1980. Otros dos también ganaron premios Nobel en otros campos: Marie Curie (física en El Premio Nobel de Química es entregado anual- 1903, química en 1911) y Linus Carl mente por la Academia Sueca a científicos que so- bresalen por sus contribuciones en el campo de la Pauling (química en 1954, paz en Física. 1962). Seis mujeres han ganado el Es uno de los cinco premios Nobel establecidos en premio: Marie Curie, Irène Joliot- el testamento de Alfred Nobel, en 1895, y que son dados a todos aquellos individuos que realizan Curie (1935), Dorothy Crowfoot Ho- contribuciones notables en la Química, la Física, la dgkin (1964), Ada Yonath (2009) y Literatura, la Paz y la Fisiología o Medicina. Emmanuelle Charpentier y Jennifer Según el testamento de Nobel, este reconocimien- to es administrado directamente por la Fundación Doudna (2020) Nobel y concedido por un comité conformado por Ha habido ocho años en los que no cinco miembros que son elegidos por la Real Aca- demia Sueca de las Ciencias. se entregó el premio Nobel de Quí- El primer Premio Nobel de Química fue otorgado mica, en algunas ocasiones por de- en 1901 al holandés Jacobus Henricus van't Hoff. clararse desierto y en otras por la Cada destinatario recibe una medalla, un diploma y situación de guerra mundial y el exi- un premio económico que ha variado a lo largo de los años. -
Synthetic Advances in the C‐H Activation of Rigid Scaffold Molecules
Synthesis Review Synthetic Advances in the C‐H Activation of Rigid Scaffold Molecules Nitika Grovera Mathias O. Senge*a a School of Chemistry, Trinity College Dublin, The University of Dublin, Trinity Biomedical Sciences Institute, 152–160 Pearse Street, Dublin 2, Ireland [email protected] Dedicated to Prof. Dr. Henning Hopf Received: only recall the epic endeavors involved in Eaton’s cubane Accepted: Published online: synthesis,3 Parquette’s preparation of dodecahedrane, DOI: Prinzbach’s pagodane route thereto, or Maier’s synthesis of Abstract The remarkable structural and electronic properties of rigid non‐ tetra-tert-butyltetrahedrane.4 conjugated hydrocarbons afford attractive opportunities to design molecular building blocks for both medicinal and material applications. The bridgehead positions provide the possibility to append diverse functional groups at specific angles and in specific orientations. The current review summarizes the synthetic development in CH functionalization of the three rigid scaffolds namely: (a) cubane, (b) bicyclo[1.1.1]pentane (BCP), (c) adamantane. 1 Introduction 2 Cubane 2.1 Cubane Synthesis 2.2 Cubane Functionalization 3 BCP 3.1 BCP Synthesis 3.2 BCP Functionalization 4 Adamantane 4.1 Adamantane Synthesis 4.2 Adamantane Functionalization 5 Conclusion and Outlook Key words Cubane, bicyclo[1.1.1]pentane, adamantane, rigid scaffolds, CH‐ functionalization. Figure 1 The structures of cubane, BCP and adamantane and the five platonic hydrocarbon systems. The fascinating architecture of these systems significantly 1 Introduction differs from scaffolds realized in natural compounds. Hence, they attracted considerable attention from synthetic and The practice of synthetic organic chemistry of non-natural physical organic chemists to investigate their properties and to compounds with rigid organic skeletons provides a deep establish possible uses.3,5 Significantly, over the past twenty understanding of bonding and reactivity. -
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