DOCSLIB.ORG

Determining Melt-Crystallization Mechanisms and Structures of Disordered Crystalline Solids

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Determining Melt-Crystallization Mechanisms and Structures of Disordered Crystalline Solids ABSTRACT DILL, ERIC DELAMARTER. Determining Melt-Crystallization Mechanisms and Structures of Disordered Crystalline Solids. (Under the direction of James D. Martin). The crystal growth kinetics of the halozeotype CZX-1 were explored with a series of isothermal crystallization experiments performed with Differential Scanning Calorimetry (DSC) and 2-D Temperature and time Resolved X-ray Diffraction (2-D TtXRD). Fitting the transformations to the well-known Kolmogorov-Johnson-Mehl-Avrami (KJMA) reaction model resulted in rate constants that appeared to be strongly dependent upon the sample size. Crystal growth simulations were designed to elucidate the relationship between the observed crystal growth rate and the sample size. These simulations unequivocally demonstrated that the KJMA rate constant is highly dependent on the sample size and the sample shape. Under the simulated conditions of slow nucleation relative to crystal growth, sample volume and sample anisotropy correction affords a means to eliminate the experimental condition dependence of the KJMA rate constant, producing the material specific parameter, the velocity of the phase boundary. Additionally, the crystallization simulations allow us to clearly define the KJMA parameters: t0 is nominally the induction time of the first crystallite in the system; n is the dimensionality of the transformation process; k, when volume and anisotropy is accounted for, is equivalent to the crystallization phase boundary velocity within a factor of two. The nucleation process in CZX-1 was explored from the “bulk” perspective with DSC and radially integrated TtXRD. No evidence for nucleation according to the mechanism proposed by Classical Nucleation Theory was found. However, a maximum in the initial nucleation “rate” was observed, defined as the inverse of the initial nucleation time from the -1 KJMA model: knuc=t0 . A method for direct analysis of the 2D TtXRD diffraction images is presented where the intensity of individual diffraction spots are fit to the KJMA model to determine their t0 and knuc values. The direct analysis of 2D diffraction images demonstrates the capability to quantitatively estimate the number of crystallites that appeared during an isothermal crystallization experiment. The structure of the plastic crystalline carbon tetrabromide, -CBr4 was investigated as a potential model of the structure of the phase boundary between liquid and crystalline phases. Two-dimensional single-crystal synchrotron X-ray diffraction of the high-temperature plastic phase of carbon tetrabromide (α-CBr4, 퐹푚3̅푚, a≈8.82 Å) was collected which reveals a twinned plastic crystal and twinned structured diffuse scattering with sharp 푮 ± {110}∗ sheets of diffuse intensity (where G represents the set of 퐹푚3̅푚 Bragg reflections). The real- space manifestation of the intense and highly structured diffuse scattering is demonstrated through 2D Patterson Function analysis. The structural understanding is augmented by a series of simulations. The analysis of the diffraction images and the simulations suggest that the CBr4 units reside in D2d site symmetry on average, consistent with previous reports. All these structural analyses find that the structure of α-CBr4 is well-described by static disorder, in clear contrast to the commonly accepted notion of the plastic phase possessing dynamic reorientational freedom. © Copyright 2014 Eric Dill All Rights Reserved Determining Melt-Crystallization Mechanisms and Structures of Disordered Crystalline Solids by Eric Delamarter Dill A dissertation submitted to the Graduate Faculty of North Carolina State University in partial fulfillment of the requirements for the degree of Doctor of Philosophy Chemistry Raleigh, North Carolina 2014 APPROVED BY: _______________________________ ______________________________ James D. Martin David A. Shultz Committee Chair ________________________________ ________________________________ Mike H. Whangbo Paul A. Maggard DEDICATION This work is dedicated to my incredible parents and my amazing wife, without whom none of this would have been possible. ii BIOGRAPHY Eric was born August 9th, 1895 in Memphis, Tennessee to parents Robert and Kristen Dill. Eric grew up in Raleigh, North Carolina and went through the Magnet program of the Wake County Public School System. He attended the John W. Ligon GT Magnet Middle school and William G. Enloe Magnet High School. He went to North Carolina State University where he pursued degrees in Chemistry and Physics. Eric began working with Professor Jim Martin as an undergraduate researcher in the 2006 when they crossed paths in Jim's Inorganic Chemistry 1 course. Eric remained at North Carolina State University to pursue a graduate degree in Inorganic Chemistry with Jim after completing his undergraduate studies. Good thing he decided to stay at NC State for graduate school because he met his amazing wife while in graduate school. iii ACKNOWLEDGEMENTS First and foremost, this work is a testament to the dedication to teaching and mentoring of my advisor, Jim. Your open door policy provides so much support to your graduate students (though I suppose you know this). I always felt that I could come ask you questions and knew that you wouldn’t feel bothered or put out by having us come ask you questions. Every day I knew I would learn something new from you, be it in the classroom while I was your TA, at group meeting, or during the course of one of our countless rounds of debate over crystallization and disorder. You taught me what it means to be a scientist by proving guidance when I needed it most and giving me the intellectual freedom of self-discovery. Jaap, my dissertation is also a testament to your open door policy and willingness to (almost always) drop everything to teach me about things that can be done with statistics that seem more like voodoo than math, to teach me about the black magic of fourier transforms and sometimes just to debate the finer points of esoteric phase transition theory (Landau, anyone?) Your ability to play devil’s advocate is unparalleled and therefore, simply put, maddening, because you’re so freaking good at it. Every time I thought I had come to a reasonable solution, you would find a clever way to poke a hole in it. I knew that I could always come to you with questions and you would always be excited to dive into the weeds. Thank you Jim and Jaap. Without these two brilliant men, the research reported in this dissertation would most certainly not have been possible. Both of you have taught me what it means to be a great teacher. Your passion for teaching and your desire to watch students succeed is inspiring. Thank you. Thank you to the Martin Group members, past and present, especially Feier, whose love of all things cute always provided a much needed break from disorder and mechanisms. Your herculean effort to beat the hydra (i.e., DSC crystallization kinetics) into reliable results proved to be a cornerstone of the crystallization mechanism research. Every time you thought you were done with that analysis, two more heads sprang up. Thank you to Amanda for being a wonderful mentor and friend and for paving the way with the crystallization mechanism studies. Thank you to Brad for becoming our resident expert in all things computationally quantum and keeping me honest about my appreciation for the dark magic of computational iv quantum mechanics! Best of luck with that zinc chloride hydrate structure and remember, if it’s yellow, let it mellow. Thank you to the wacky and wild cast of undergraduate researchers that I’ve worked with over the years. Eric R., you’re one of the finest people I’ve ever met and it was wonderful to be able to work with and mentor you over the years. Elijah, I wish we had a chance to work together more, but best of luck in graduate school! I know you guys will do incredible things. To Mick the pirate; keep doing your thing because you’re awesome at it. I will most certainly miss those days when I walk into the lab and there’s a pirate carefully tinkering with the microbalance. James, keep on doing your thing. You’ve got the incredible gift of creating seemingly magical devices from everyday things. That dip-probe spectrometer will probably amaze me until the day I die. Daniel, even though your time with us at NC State was short and you’ll likely return to Brown to finish your studies, you’re the most dedicated undergraduate student I’ve ever met and your work ethic is unparalleled. I know you’ll be successful at whatever you set your mind to. Perhaps you’ve got enough baseball gloves though? Troy, though we only had limited interaction, I feel comfortable advising you to watch out for exploding (or was it an implosion?) drybox gloves. It’s been an absolute treat to work with all of you over the years. Please consider me a resource to pull from whenever you need and let me know if I can ever be of assistance! (Brad and Feier, that goes for you too!) Thank you to Dave B. and Rob K., who were always willing to listen to me babble on about crystallization mechanisms and disordered materials, even when you would rather be doing (literally) almost anything else. Thank you to Justin K. for being a great friend and overnight-work-companion when we ended up on the same weird schedule while I was writing my prelim and you were writing your dissertation. Thank you to those of you who participated in those weekly morning meetings and the biweekly writing workshops in the spring semester of 2013 (Michael, Meghan, Alecia, Ryan, Sandra, Suzanne, Timia, Rhonda and Mike). Those meetings took quite a lot of the sting out of the dissertation writing process. Finally, thank you to my committee members: Dr. Mike Whangbo, Dr. David Shultz, Dr. Paul Maggard and Dr. Mike Carter; for taking the time to read this document and for taking v part in my final defense.
Load more

Recommended publications
  • PAPERS READ BEFORE the CHEMICAL SOCIETY. XXII1.-On
    View Article Online / Journal Homepage / Table of Contents for this issue 773 PAPERS READ BEFORE THE CHEMICAL SOCIETY. XXII1.-On Tetrabromide of Carbon. No. II. By THOMASBOLAS and CHARLESE. GROVES. IN a former paper* we described several methods for the preparation of the hitherto unknown tetrabromide of carbon, and in the present communication we desire to lay before the Society the results of our more recent experiments. In addition to those methods of obtaining the carbon tetrabromide, which we have already published, the fol- lowing are of interest, either from a theoretical point of view, or as affording advantageous means for the preparation of that substance. Action of Bromine on Carbon Disulphide. Our former statement that? bromine had no action on carbon disul- phide requires some modification, as we find that when it is heated to 180" or 200" for several hundred hours with bromine free from both chlorine and iodine, and the contents of the tubes are neutralised and distilled in the usual way, a liquid is obtained, which consists almost entirely of unaltered carbon disulphide ; but when this is allowed to evaporate spontaneously, a small quantity of a crystalline substance is left, which has the appearance and properties of carbon tetrabromide. The length of time required for this reaction, and the very small relative amount of substance obtained, would, however, render this Published on 01 January 1871. Downloaded by Brown University 25/10/2014 10:39:25. quite inapplicable as a process for the preparation of the tetra- bromide. Action of Bromine on Carbon Disdphide in, presence of Certain Bromides.
    [Show full text]
  • Crystal Structure Transformations in Binary Halides
    1 A UNITED STATES DEPARTMENT OF A111D3 074^50 IMMERCE JBLICAT10N NSRDS—NBS 41 HT°r /V\t Co^ NSRDS r #C£ DM* ' Crystal Structure Transformations in Binary Halides u.s. ARTMENT OF COMMERCE National Bureau of -QC*-| 100 US73 ho . 4 1^ 72. NATIONAL BUREAU OF STANDARDS 1 The National Bureau of Standards was established by an act of Congress March 3, 1901. The Bureau's overall goal is to strengthen and advance the Nation’s science and technology and facilitate their effective application for public benefit. To this end, the Bureau conducts research and provides: (1) a basis for the Nation’s physical measure- ment system, (2) scientific and technological services for industry and government, (3) a technical basis for equity in trade, and (4) technical services to promote public safety. The Bureau consists of the Institute for Basic Standards, the Institute for Materials Research, the Institute for Applied Technology, the Center for Computer Sciences and Technology, and the Office for Information Programs. THE INSTITUTE FOR BASIC STANDARDS provides the central basis within the United States of a complete and consistent system of physical measurement; coordinates that system with measurement systems of other nations; and furnishes essential services leading to accurate and uniform physical measurements throughout the Nation’s scien- tific community, industry, and commerce. The Institute consists of a Center for Radia- tion Research, an Office of Measurement Services and the following divisions: Applied Mathematics—Electricity—Heat—Mechanics—Optical Physics—Linac Radiation 2—Nuclear Radiation 2—Applied Radiation 2—Quantum Electronics 3— Electromagnetics 3—Time and Frequency 3—Laboratory Astrophysics 3—Cryo- 3 genics .
    [Show full text]
  • Isoflurane, 2-Halogenated Ethanols, and Halogenated Methanes Activate TASK-3 Tandem Pore Potassium Channels Likely Through a Similar Mechanism
    Isoflurane, 2-Halogenated Ethanols, and Halogenated Methanes Activate TASK-3 Tandem Pore Potassium Channels Likely Through a Similar Mechanism. Authors: Joseph F. Cotten, M.D.,Ph.D1., Anita Luethy, M.D.1,2 1Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA. 2Department of Anesthesia, Kantonsspital Aarau, Aarau, Switzerland. Background: TASK-3 (KCNK9) tandem pore potassium channel proteins mediate a constitutive potassium conductance activated by several clinically relevant volatile anesthetics (e.g., halothane, isoflurane, sevoflurane, and desflurane); knockout mice lacking the TASK-3 potassium channel are resistant to the hypnotic and immoblizing effects of halothane and isoflurane. Purpose: To better understand the molecular mechanism by which TASK-3 channels are activated by anesthetics, we studied the functional concentration-response of wild-type TASK-3 potassium channels to isoflurane, to ethanol, and to several halogenated ethanols and methanes. We also studied the concentration-response of M159W TASK-3 to 2,2,2- trichloroethanol; the M159W TASK-3 mutant is known to be resistant to isoflurane activation (1). 2,2,2-trichloroethanol, notably, is an active metabolite of the sedative chloral hydrate; and 2,2,2-tribromoethanol is the active ingredient in Avertin, an injectable veterinary anesthetic. Methods: Wild-type and M159W TASK-3 function were studied by Ussing chamber voltage clamp analysis during transient expression in Fischer rat thyroid cell monolayers. Results: 2-halogenated ethanols activate wild-type TASK-3 with the following rank order for efficacy: 2,2,2-tribromo > 2,2,2-trichloro > chloral hydrate > 2,2-dichloro > 2-chloro ≈ 2,2,2- trifluoro > ethanol (Table 1).
    [Show full text]
  • 2020 Emergency Response Guidebook
    2020 A guidebook intended for use by first responders A guidebook intended for use by first responders during the initial phase of a transportation incident during the initial phase of a transportation incident involving hazardous materials/dangerous goods involving hazardous materials/dangerous goods EMERGENCY RESPONSE GUIDEBOOK THIS DOCUMENT SHOULD NOT BE USED TO DETERMINE COMPLIANCE WITH THE HAZARDOUS MATERIALS/ DANGEROUS GOODS REGULATIONS OR 2020 TO CREATE WORKER SAFETY DOCUMENTS EMERGENCY RESPONSE FOR SPECIFIC CHEMICALS GUIDEBOOK NOT FOR SALE This document is intended for distribution free of charge to Public Safety Organizations by the US Department of Transportation and Transport Canada. This copy may not be resold by commercial distributors. https://www.phmsa.dot.gov/hazmat https://www.tc.gc.ca/TDG http://www.sct.gob.mx SHIPPING PAPERS (DOCUMENTS) 24-HOUR EMERGENCY RESPONSE TELEPHONE NUMBERS For the purpose of this guidebook, shipping documents and shipping papers are synonymous. CANADA Shipping papers provide vital information regarding the hazardous materials/dangerous goods to 1. CANUTEC initiate protective actions. A consolidated version of the information found on shipping papers may 1-888-CANUTEC (226-8832) or 613-996-6666 * be found as follows: *666 (STAR 666) cellular (in Canada only) • Road – kept in the cab of a motor vehicle • Rail – kept in possession of a crew member UNITED STATES • Aviation – kept in possession of the pilot or aircraft employees • Marine – kept in a holder on the bridge of a vessel 1. CHEMTREC 1-800-424-9300 Information provided: (in the U.S., Canada and the U.S. Virgin Islands) • 4-digit identification number, UN or NA (go to yellow pages) For calls originating elsewhere: 703-527-3887 * • Proper shipping name (go to blue pages) • Hazard class or division number of material 2.
    [Show full text]
  • Study on Telomerization of Methyl Methacrylate with Carbon Tetrabromide and Characteristics of the Resulting Adducts
    Polymer JournaL Vol. 24. No.2, pp 187-197 (1992) Study on Telomerization of Methyl Methacrylate with Carbon Tetrabromide and Characteristics of the Resulting Adducts Takao KIMURA,* Hiroshi EzuRA,t and Motome HAMASHIMAtt Department of Applied Chemistry, Faculty of Engineering, Utsunomiya University, Ishii-machi, Utsunomiya 321, Japan (Received July 4, 1991) ABSTRACT: Using carbon tetrabromide (CTB) as a telogen, the radical telomerization of methyl methacrylate (MMA) was carried out with varying temperature, molar ratio of CTB to MMA, and with or without benzene as solvent. The telomerization behavior of MMA, and structure and properties of the resulting adducts were compared with those in MMA-bromotrichloromethane (BTCM) system. The telomerization using CTB gave preferentially adducts with a lower average degree of telomerization (ii) than that using BTCM. A kind of linear rnonoadduct (n= 1), two kinds of linear diadducts (n = 2), two kinds of cyclic diadducts (n = 2), and two kinds of linear triadducts (n = 3) were isolated, and the structures of all adducts were determined by 1 H, 13C, and 20 NMR techniques. It was found that the linear diadducts from CTB show a lowering of the priority ofsyndiotacticity and higher extent of cyclization in comparison with the ones from BTCM. KEY WORDS Telomerization I Methyl Methacrylate I Carbon Tetra- bromide I Bromo trichloromethane I Linear Adduct I Cyclic Adduct I Nuclear Magnetic Resonance I Diastereoisomcr I Tacticity I Lactonization I The concept of telomerization has been from dimers to octamers from stereoregular known for a long time.u In particular, living polymerization systems of MMA, and halo- and sulfur-compounds as telogens play investigated the 1 H and 13C NMR spectra of an important part in the radical telomerization the pure diastereoisomers in detail.
    [Show full text]
  • Carbon Tetrabromide
    SPOTLIGHT ██889 SYNLETT Carbonspotlight Tetrabromide Spotlight 429 Compiled by Zhong-Yan Cao This feature focuses on a re- agent chosen by a postgradu- Zhong-Yan Cao was born in Bozhou, P. R. of China, and received ate, highlighting the uses and his B.Sc. from East China Normal University in 2010. Currently he preparation of the reagent in is pursuing his Ph.D. under the supervision of Professor Jian Zhou at the same university. His research interests focus on the develop- current research ment of new catalysts and new methodologies for constructing tetrasubstituted carbon centers. Shanghai Key Laboratory of Green Chemistry and Chemical Pro- cesses, Department of Chemistry, East China Normal University, North Zhongshan Road 3663, Shanghai 200062, P. R. China E-mail: [email protected] Introduction alkenes4 or alkynes5 (Corey–Fuchs reaction). In addition, carbon tetrabromide is a highly efficient catalyst for ver- Carbon tetrabromide, also known as tetrabromomethane, satile reactions, including acylation of phenols, alcohols is a commercially available white solid which is stable at and thiols,6 acetalization and tetrahydropyranylation7 and room temperature and can be easily handled. It is prepared oxidation of aromatic methyl ketones8 or alkenes9 to car- either by the complete bromination of methane or by the boxylic acids under very mild conditions. Carbon tetra- reaction of tetrachloromethane with aluminum bromide. bromide can further promote the synthesis of thioureas In combination with a tertiary phosphine, it has been used and thiuram disulfides.10 Apart from these applications, for the bromination of various functional groups, such as carbon tetrabromide is also used as a crystal growth11 and alcohols (Appel reaction),1 N-heterocycles,2 ethers,3 and chain transfer agent12 in polymer chemistry.
    [Show full text]
  • Ring-Opening Polymerization of \Varepsilon-Caprolactone Using Novel Dendritic Aluminum Alkoxide Initiators
    Polymer Journal, Vol. 37, No. 11, pp. 847–853 (2005) Ring-Opening Polymerization of "-Caprolactone Using Novel Dendritic Aluminum Alkoxide Initiators y Takahito MURAKI, Ken-ichi FUJITA, Akihiro OISHI, and Yoichi TAGUCHI National Institute of Advanced Industrial Science and Technology (AIST), AIST Tsukuba Central 5, 1-1-1, Higashi, Tsukuba 305-8565, Japan (Received June 29, 2005; Accepted July 20, 2005; Published November 15, 2005) ABSTRACT: We have prepared two novel dendritic aluminum alkoxide initiators for ring-opening polymerization. An aluminum trialkoxide dendrimer was prepared from triethylaluminum and dendritic alcohol, and an aluminum den- drimer embedded by bidentate ligation of the dendritic -glycol was prepared from diethylaluminum ethoxide and a novel dithiothreitol-derived dendritic ligand. These aluminum dendrimers were each applied as an initiator for ring- opening polymerization of "-caprolactone, and each one showed high reactivity. Furthermore, when the dithiothrei- tol-derived dendrimer was used as the initiator, the higher the generation from which the dendrimer was derived, the narrower the polydispersity (Mw=Mn) of poly("-caprolactone) was. This relationship between the generation of the dendritic initiator and polydispersity is one of the positive dendritic effects. [DOI 10.1295/polymj.37.847] KEY WORDS Dendrimer / Ring-opening Polymerization / Poly("-caprolactone) / Dendritic Effect / Recent concerns about the environment call for the O development of environmentally benign materials. O One of the most practical materials is biodegradable aliphatic polyesters, such as poly("-caprolactone) O (PCL) and poly(lactide).1 PCL is generally prepared MO OR by ring-opening polymerization of "-caprolactone ("-CL) through the use of metal alkoxides such as alu- minum triisopropoxide2 and titanium tetrabutoxide3 as O initiators.
    [Show full text]
  • Chemical Inventory
    Name CAS Number SOP Status Supplier Size Qt. Location Received Purchaser Hazards (1,3-bis)2,4,6-trimethylphenyl)-4,5-dihydroimidazol-2-ylidene[2-(i-propoxy)-5-(N,N-dimethyl aminosulfonyl)phenyl]methylene Ru(II) dichloride918870-76-5 100mg 1 Storage # 3 (2-bromoethyl) benzene 98% 103-63-9 100G 2 Storage # 3 (3-aminopropyl)triethoxysilane 919-30-2 Sigma 100 mL 1 Storage #3 Apr-13 Stephanie Flammable, toxic, corrosive (3-aminopropyl)trimethoxysilane 13822-56-5 Sigma 100 mL 1 small fridge May-13 Stephanie Corrosive, irritant (3-iodopropyl)trimethoxysilane 14867-28-8 1 Storage # 2 (3-mercaptopropyl) trimethoxysilane 95% 4420-74-0 25g 1 Shelf # 3 (3-mercaptopropyl)-trimethoxysilane 95% 4420-74-0 25G 2 Storage # 2 (iodomethyl)trimethylsilane 4206-67-1 5mL 1 Storage # 2 (Propan-2-yloxy) benzene 2741-16-4 Enamine 1g 1 Storage # 3 Nov-14 Zach (Trimethylsilyl)methyllithium, 1.0M solution in pentane 1822-00-0 SOP on file-Lithium reagents Aldrich 50ml 1 Large fridge Highly flammable 0.5% Rhodium on 1/8 Alumina pellets 7440-16-6 25g 2 Shelf # 1 1% Pt-Al-1DR 7440-06-4 74292-90-5 0.05kg 1 Shelf # 1 1-(2-hydroxyethyl)-2-pyrolidinone 98% 3445-11-2 5ml 2 Storage # 3 1-(Trimethylsiloxy)cyclohexene 6651-36-1 Alfa 1g 1 Small fridge Mar-14 Bethany 1,1,1,3,3,3-Hexafluoro-2-propanol, 99+% 920-66-1 25g 1 Storage # 4 1,1,1,3,3,3-Hexafluoro-2-propanol-d9, 99 atom%D 38701-74-5 1g 2 Storage #7 1,1,1,3,3,3-hexamethyl-disilane 99.9% 1450-14-2 100mL 2 Storage # 2 1,1,2,2-Tetra chloroethane-D2 (D, 99.6%) 33685-54-0 SOP on file- Acutely toxic chem.
    [Show full text]
  • 40 CFR Ch. I (7–1–06 Edition)
    § 60.667 40 CFR Ch. I (7–1–06 Edition) to all continuous programs of compo- Chemical name CAS No.* nent replacement which are com- Citric acid ........................................................... 77–92–9 menced within any 2-year period fol- Crotonaldehyde ................................................. 4170–30–0 lowing December 30, 1983. For purposes Crotonic acid ...................................................... 3724–65–0 of this paragraph, ‘‘commenced’’ means Cumene ............................................................. 98–82–8 Cumene hydroperoxide ..................................... 80–15–9 that an owner or operator has under- Cyanuric chloride ............................................... 108–77–0 taken a continuous program of compo- Cyclohexane ...................................................... 110–82–7 nent replacement or that an owner or Cyclohexane, oxidized ....................................... 68512–15–2 operator has entered into a contractual Cyclohexanol ..................................................... 108–93–0 Cyclohexanone .................................................. 108–94–1 obligation to undertake and complete, Cyclohexanone oxime ....................................... 100–64–1 within a reasonable time, a continuous Cyclohexene ...................................................... 110–83–8 program of component replacement. 1,3-Cyclopentadiene .......................................... 542–92–7 Cyclopropane ..................................................... 75–19–4 Diacetone
    [Show full text]
  • The Application of a Monolithic Triphenylphosphine Reagent for Conducting Appel Reactions in Flow Microreactors
    The application of a monolithic triphenylphosphine reagent for conducting Appel reactions in flow microreactors Kimberley A. Roper1, Heiko Lange1, Anastasios Polyzos1, Malcolm B. Berry2, Ian R. Baxendale1 and Steven V. Ley*1 Full Research Paper Open Access Address: Beilstein J. Org. Chem. 2011, 7, 1648–1655. 1Innovative Technology Centre, Department of Chemistry, University doi:10.3762/bjoc.7.194 of Cambridge, Lensfield Road, Cambridge, Cambridgeshire, CB2 1EW, UK and 2GlaxoSmithKline, Gunnels Wood Road, Stevenage, Received: 30 September 2011 Hertfordshire, SG1 2NY, UK Accepted: 16 November 2011 Published: 08 December 2011 Email: Steven V. Ley* - [email protected] This article is part of the Thematic Series "Chemistry in flow systems II". * Corresponding author Guest Editor: A. Kirschning Keywords: © 2011 Roper et al; licensee Beilstein-Institut. Appel reaction; bromination; flow chemistry; solid-supported reagent; License and terms: see end of document. triphenylphosphine monolith Abstract Herein we describe the application of a monolithic triphenylphosphine reagent to the Appel reaction in flow-chemistry processing, to generate various brominated products with high purity and in excellent yields, and with no requirement for further off-line puri- fication. Introduction Flow chemistry is well-established as a useful addition to the these can suffer from poor mass transfer as well as presenting toolbox of the modern research chemist, with advantages practical problems caused by the swelling or compression char- accrued through increased efficiency, reproducibility and reac- acteristics of the beads related to the solvent employed. To tion safety [1-6]. Further benefits can be realised when flow circumvent some of the issues with bead-type supports, mono- processing techniques are combined with the use of solid- liths have been developed as replacements for use in supported reagents and scavengers, which allow telescoping of continuous-flow synthesis.
    [Show full text]
  • Carbon Tetrachloride (PDF)
    United States Office of Air Quality EPA-450/4-84-007b Environmental Protection Planning And Standards Agency Research Triangle Park, NC 27711 March 1984 AIR EPA LOCATING AND ESTIMATING AIR EMISSIONS FROM SOURCES OF CARBON TETRACHLORIDE L &E EPA-450/4-84-007b March 1984 Locating And Estimating Air Emissions From Sources Of Carbon Tetrachloride U.S. ENVIRONMENTAL PROTECTION AGENCY Office Of Air And Radiation Office Of Air Quality Planning And Standards Research Triangle Park, North Carolina 27711 This report has been reviewed by the Office Of Air Quality Planning And Standards, U.S. Environmental Protection Agency, and has been approved for publication as received from GCA Technology. Approval does not signify that the contents necessarily reflect the views and policies of the Agency, neither does mention of trade names or commercial products constitute endorsement or recommendation for use. CONTENTS Figures ............................ iv Tables ............................ vi 1. Purpose of Document ................... 1 2. Overview of Document Content .............. 3 3. Background ....................... 5 Nature of Pollutant ................... 5 Overview of Production and Use ............. 8 4. Carbon Tetrachloride Emission Sources ......... 11 Carbon Tetrachloride Production ............ 11 Fluorocarbon Production ................ 26 Carbon Tetrabromide Production ............ 32 Liquid Pesticide Formulation ............. 35 Pharmaceutical Manufacturing ............. 39 Use of Pesticides Containing Carbon Tetrachloride ... 42 Ethylene
    [Show full text]
  • Oct. 5, 1965 A
    Oct. 5, 1965 A. C. KNIGHT 3,210,430 PREPARATION OF TETRAFLUOROETHYLENE Filed May 24, l963 INVENTOR ALAN C. KNIGHT BY ATTZRNEY 3,210,430 United States Patent Office Patented Oct. 5, 1965 2 The process of the present invention is based on the PREPARATION OF 320,430fifAFLUOROETHYLENE discovery that brominated by-products formed in the Alan Campiel Knight, Wilmington, Dei, assignor to E. E. various reactions involved in the process can either be du Pont de Nemoirs and Company, Winington, e. recycled or can be decomposed to result in the recovery a corporation of Delaware of bromine to such a degree that substantially no bro Filed May 24, 1963, Ser. No. 285,88 imine i.e., less than 3% is lost in the process. Hence, 3 Cains. (C. 260-653.3) the process requires only the use of methane, oxygen and hydrogen fluoride and produces substantially no This application is a continuation in part of S.N. 137, products other than tetrafluoroethylene. The process of 685 filed September 12, 1961, now abandoned. O the present invention differs significantly from a process The present invention relates to the preparation of based on an analogous system using, instead of bromine, tetrafluoroethylene, and, more particularly, to a process chlorine. In such a process carbon tetrachloride is for the preparation of tetrafluoroethylene which employs formed as a by-product which makes the complete re substantially only methane, oxygen and hydrogen fluoride covery of the chlorine for purposes of recycle difficult if and produces essentially no unfluorinated side products. 5 not impossible because of the difficulties encountered in Tetrafluoroethylene is an unsaturated fluorocarbon the oxidation of carbon tetrachloride to chlorine which compound which is produced commercially on a large only gives rise to low yields of chlorine.
    [Show full text]