DOCSLIB.ORG

Nsu-Ehs-Chemical-Hygiene-Plan-2018

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Nsu-Ehs-Chemical-Hygiene-Plan-2018 ENVIRONMENTAL NOVA SOUTHEASTERN HEALTH AND SAFETY UNIVERSITY POLICY/PROCEDURE TITLE: POLICY/PROCEDURE Chemical Hygiene Plan NUMBER: 3 DOCUMENT HISTORY OWNER: Facilities Management/AHIS Date: 1 Sept 2011 APPROVED: NSU EHS Committee Date: 1 Sept 2013 IMPLEMENTED: Date: 1 Oct 2010 RETIRED: Date: Date: Revision No. Review / Changes Reviewer 7 August 2013 none 11 May 2018 1.0 Added EHS instead of EH&S and replaced MSDS with C. St Louis SDS CHEMICAL HYGIENE PLAN TABLE OF CONTENTS Section 1: Introduction Page 4 Section 2: Chemical Safety Guidelines Page 7 Section 3: Chemical Hygiene Responsibilities Page 9 Section 4: Exposure Assessments and Medical Surveillance Page 12 Section 5: Safety Data Sheets - SDS Page 16 Section 6: Chemical Labels Page 17 Section 7: Hazard Communication Page 18 Section 8: Permissible Exposure Limits Page 21 Section 9: Engineering Controls Page 22 Section 10: Classification of Hazardous Substances Page 32 Section 11: Chemical Handling Labeling and Storage Page 47 Section 12: Chemical Inventory Page 61 Section 13: Compressed Gas Safety Page 62 Section 14: Spill Response and Clean-up Guidelines Page 65 Section 15: Shipping / Receiving Chemicals Page 69 Section 16: Training Page 70 Section 17: Record Keeping Page 72 Section 18: Chemical Waste Disposal Page 73 Tables and Illustrations Table A: General Classes of Fires and Fire Extinguishers Page 23 Table B: Flammable and Combustible Liquids Class Characteristics Page 35 Table C: Solvent Substitutions Page 37 Table D: Common Cleaning Agents/Hazards/Precautions Page 45 Table E: Shelf Life of Unstable Chemicals Page 61 Table F: Types of Chemical Spills Page 65 Table G: Record Keeping Page 72 Table H: Chemical Substitutions Page 78 Illustration 1: NFPA System for Classification of Hazards Page 17 Appendices Appendix A: Laboratory Decommissioning Checklist Page 79 Appendix B: Safety Data Sheets Page 81 Appendix C: HMIS - Hazardous Materials Identification System Page 85 Appendix D: Chemical Storage and Labeling Page 78 Appendix E: Hazard Communication - Employee Training Certification Page 89 Appendix F: Eyewash Maintenance Weekly Log Sheet Page 90 Appendix G: Personal Protective Equipment Types Page 91 Appendix H: Hazard Assessment Form Page 92 Appendix I: Glove Selection Chart Page 94 Appendix J: Common Laboratory Corrosives Page 95 Page 2 of 121 CHEMICAL HYGIENE PLAN Appendix K: Common Laboratory Oxidizers Page 96 Appendix L: Classes of Peroxidizable Chemicals Page 97 Appendix M: OSHA Regulated Carcinogens Page 99 Appendix N: Incompatible Chemicals Page 100 Appendix O: Listed Hazardous Waste Page 101 Appendix P: EPA Uniform Hazardous Waste Manifest Page 103 Appendix Q: Table Z-1 Limits of Air Contaminants Page 104 Appendix R: Table Z-2 Limits of Air Contaminants Page 119 Appendix S: Table Z-3 Mineral Dusts Page 120 Page 3 of 121 CHEMICAL HYGIENE PLAN Section 1: Introduction Nova Southeastern University is committed to establishing and maintaining safe and healthy working conditions and to promote safe practices by all staff, faculty and students. The University is also committed to working in ways that reflect its deep concern for its neighbors and for the quality of the surrounding environment. The goals of implementing the Chemical Hygiene Plan include: 1. Minimizing the risk of chemical exposure; 2. Minimizing the risk of work-related injury and illness; 3. Minimizing the risk to the environment; 4. Compliance with applicable regulations and standards; 5. Achievement of goals with a minimum burden on research and clinical activities. The Occupational Safety and Health Administration (OSHA), a part of the Department of Labor, administers a variety of regulations and published in and referred to as the Code of Federal Regulations (CFR). Part 1910 of Title 29 (cited as "29 CFR 1910"), section 1450 of subpart Z, "Occupational Exposures to Hazardous Chemicals in Laboratories", referred to as the "Laboratory Standard", and specifically addresses mandated regulatory requirements. An effective chemical hygiene plan necessitates that mechanisms be in place and functioning to ensure that safety policies and procedures are being adhered to; personnel are meeting their safety responsibilities; and an effective form of monitoring and documentation is in place for confirmation purposes. Chemical safety is inherently linked to other safety issues including laboratory procedures, personal protective equipment, electrical safety, fire safety, and hazardous waste disposal. The development of a detailed written chemical hygiene plan and the implementation of this plan within employee and student training programs should result in a safer working environment and contribute to a reduction in work place accidents and injuries. 1.1 Scope Almost everyone works with or around chemicals and chemical products every day. Many of these materials have properties that make them hazardous, i.e. they can create physical (fire, explosion) and/or health hazards (toxicity, chemical burns). There are many ways to work with chemicals which can both reduce the probability of an accident to a negligible level and reduce the consequences to minimum levels should an accident occur. Risk minimization depends on safe practices, appropriate engineering controls for chemical containment, the proper use of personal protective equipment, the use of the least quantity of material necessary, and substitution of a less hazardous chemical for the more hazardous one. Before beginning an operation, ask "What would happen if...?" The answer to this question requires an understanding of the hazards associated with the chemicals, equipment and procedures involved. The hazardous properties of the material and intended use will dictate the precautions to be taken. Page 4 of 121 CHEMICAL HYGIENE PLAN Another important distinction is the difference between hazard and risk. The two terms are sometimes used as synonyms. In fact, hazard is a much more complex concept because it includes conditions of use. The hazard presented by a chemical has two components: (1) its inherent capacity to do harm by virtue of its toxicity, flammability, explosiveness, corrosiveness, etc., and (2) the ease with which the chemical can come into contact with a person or other object of concern. The two components together determine risk (the likelihood or probability that a chemical will cause harm). Thus, an extremely toxic chemical such as strychnine cannot cause poisoning if it is in a sealed container and does not contact the handler. In contrast, a chemical that is not highly toxic can be lethal if a large amount is ingested. Knowledge + Common Sense + Caution = Chemical Safety Not all chemicals are considered hazardous. Examples of nonhazardous chemicals include buffers, sugars, starches, agar, and naturally occurring amino acids. 1.2 Definitions Action level: A concentration for a specific substance, calculated as an eight (8) hour time- weighted average, which initiates certain required activities such as exposure monitoring and medical surveillance. Typically it is one-half that of the PEL for that substance. Acute: Severe, often dangerous conditions in which relatively rapid changes occur. Carcinogen: Any substance that causes the development of cancerous growths in living tissue, either those that are known to induce cancer in man or animals or experimental carcinogens that have been found to cause cancer in animals under experimental conditions. Designated Area: An area which may be used for work with select carcinogens, reproductive toxins, or substances which have a high degree of acute toxicity. Health Hazard: A substance for which there is statistically significant evidence based on at least one study conducted in accordance with established scientific principles that acute or chronic health effects may occur if exposed. This term includes carcinogens, toxic agents, reproductive toxins, irritants, corrosives, sensitizers, hepatotoxins, nephrotoxins, and neurotoxins, agents which act on the hematopoietic systems, and agents which damage the lungs, skin, eyes, or mucous membranes. SDS (Safety Data Sheets): Formal document containing important information about the characteristics and actual or potential hazards of a substance. It identifies the manufacturer of the material (with name, address, phone, and fax number) and usually includes (1) chemical identity, (2) hazardous ingredients, (3) physical and chemical properties, (4) fire and explosion data, (5) reactivity data, (6) health hazards data, (7) exposure limits data, (8) precautions for safe storage and handling, (9) need for protective gear, and (10) spill control, cleanup, and disposal procedures. Page 5 of 121 CHEMICAL HYGIENE PLAN PEL (Permissible Exposure Limit): An exposure limit that is published and enforced by OSHA as a legal standard. PEL may be either a time-weighted-average (TWA) exposure limit (8 hour), a 15-minute short term exposure limit (STEL) or a ceiling (C). The PELs are found in Tables Z-1, Z-2, or Z-3 of 29 CFR 1910.1000 (see Appendix Q, R, and S). This level of exposure is deemed to be the maximum safe concentration and is generally the same value as the threshold limit value (TLV). PPE (Personal Protective Equipment): Any devices or clothing worn by personal to protect against hazards in the environment. Examples are respirators, gloves, and chemical splash goggles. Respirator: A device which is designed to protect the wearer from inhaling harmful contaminants. STEL (Short Term Exposure Limit): Represented as STEL or TLV-STEL, this is the maximum
Load more

Recommended publications
  • Unusual Ring Opening of Hexamethyl Dewar Benzene in Its Reaction with Triosmium Carbonyl Cluster
    Organometallics 2003, 22, 2361-2363 2361 Unusual Ring Opening of Hexamethyl Dewar Benzene in Its Reaction with Triosmium Carbonyl Cluster Wen-Yann Yeh* and Yu-Chiao Liu Department of Chemistry, National Sun Yat-Sen University, Kaohsiung, Taiwan 804 Shie-Ming Peng and Gene-Hsiang Lee Department of Chemistry, National Taiwan University, Taipei, Taiwan 106 Received April 15, 2003 6 Summary: Os3(CO)10(NCMe)2 catalyzes the transforma- HMDB produces the HMB complex [(η -C6Me6)Fe- 11 tion of hexamethyl Dewar benzene (HMDB) to hexameth- (CO)2]2. In rare cases the HMDB moiety has lost its ylbenzene (HMB). This catalytic reaction is in competi- unity, such as in the reaction of RhCl3‚xH2O with 5 tion with ring opening of the HMDB ligand to give (µ- HMDB, causing a ring contraction to give [(η -C5Me5)- 3 12 H)2Os3(CO)9(µ-η -CH(C6Me5)) (1) and (µ-H)Os3(CO)9(µ3- RhCl2]2. However, the coordination chemistry of HMDB 2 t η -C C(C4Me4Et)) (2). with metal clusters has received little attention. We now The coordination chemistry of strained hydrocarbons report that Os3(CO)10(NCMe)2 not only catalyzes the has fascinated chemists striving to understand the conversion of HMDB to HMB but also causes unusual - - details of structure and reactivity.1 In particular, ben- C H and C C bond activations of the HMDB ligand to zene is rich with high-energy strained isomers, such as form unique cluster complexes. Dewar benzene, prismane, and benzvalene, which in- Treatment of Os3(CO)10(NCMe)2 with HMDB (4-fold) terconvert through complex and mysterious rearrange- at
    [Show full text]
  • Prismane Structure by Silicon Substitution†
    J. Chem. Sci. Vol. 129, No. 7, July 2017, pp. 911–917. © Indian Academy of Sciences. DOI 10.1007/s12039-017-1264-8 REGULAR ARTICLE Special Issue on THEORETICAL CHEMISTRY/CHEMICAL DYNAMICS Stabilisation of the [6]-prismane structure by silicon substitution† ASIF EQUBALa, SHWETHA SRINIVASANa and NARAYANASAMI SATHYAMURTHYa,b,∗ aDepartment of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Sector 81, SAS Nagar, Manauli, 140 306, India bDepartment of Chemistry, Indian Institute of Technology Kanpur, Kanpur, 208 016, India E-mail: [email protected] MS received 9 January 2017; revised 6 March 2017; accepted 17 March 2017 Abstract. Using the second-order Møller–Plesset perturbation (MP2) theoretic method and the cc-pVDZ basis set, it is shown that with an increase in the number of carbon atoms substituted by silicon, the [6]-prismane structure becomes increasingly more stable, relative to the two isolated benzene (like) structures. A similar trend is observed for germanium substituted prismanes as well. Extending this investigation, the stability of benzene-capped fullerene (C60 fused with benzene) is also investigated. Keywords. [6]-Prismane; silabenzene; germanobenzene; benzene-capped fullerene. 1. Introduction readily achieved, 22–25 synthesis of [6]-prismane remained a challenge until Mehta and Padma 26,27 came up with Benzene is known to be highly stable. The interaction of a novel idea to synthesize it using Diels-Alder addi- two benzene molecules has been investigated over the tion and photocatalysis. [6]-Prismane has the structure years, and the parallel displaced and T-shaped geome- of a regular hexagonal prism wherein two parallel 6- tries have been shown to be comparable in stability from membered rings are co-joined face-to-face resulting a theoretical point of view.
    [Show full text]
  • Triprismane (CH)6
    Triprismane (CH)6 Ein DaMocles Projekt von • Heiko Hofmann • Nina Hundertmark • Fatema Rad • Regina Sander Contents Introduction…………………………………………...page 1 Chemical and physical informations………………...page 2 Stability………………………………………………..page 3 Preparation……………………………………………page 4 - 6 Research and Development…………………………..page 7 - 8 References……………………………………………..page 9 Introduction Triprismane is the smallest and probably most famous member of a class of extraordinary and interesting polyhederanes, the [n]-prismanes. The smallest member of this hydrocarbon family was proposed by Ladenburg in 1869 as structure for benzene, and more than a century ago, the existence of triprimane became part of a discussion about cage compounds. Formally these cage compounds consist of an even number of methine units positioned at the corners of a regular prism. It's very high symmetry and their complex structure makes them not only difficult to preparate, but also highly strained. The conservation of orbital symmetry, publicised by Woodward and Hoffmann, is the most important facet about the durableness of triprismane and its thermodynamic stability. In 1965 Woodward won the nobel prize of chemistry for these rules. Seite 1 von 9 1.) Chemical and physical informations [3]-prismane [4]-prismane [5]-prismane [6]-prismane (ΔHf = 1338,9 kJ/mol) (ΔHf = 719,7 kJ/mol) (ΔHf = 602,5 kJ/mol) (ΔHf = 686,2 kJ/mol) ΔHf(Benzol) = 961,9 kJ/mol) These interpretations have been predicted by MM2 calculations as they are also used by programmes like ChemDraw. Empirical formula C6H6 CAS RN (Registry 650-42-0 N°) Name: IUPAC: teracylo[2.2.0.02,6.03,5]-hexane prismane, [3]-prismane, triprismane, ladenburg-Benzene.
    [Show full text]
  • Molecule of the Month Isomers of Benzene - Still Pursuing Dreams
    fEATURE I ARTICLE Molecule of the Month Isomers of Benzene - Still Pursuing Dreams J Chandrasekhar Three new DlDnocyclic C6H6 isomers which are highly J Chandrasekhar is at the Department of Organic strained have been made in recent years. Chemistry of the Indian Ins­ titute of Science, Bangalore. Michael Faraday opened up a new chapter in chemistry when he isolated benzene from the distillate of coal tar. The deceptively simple molecule with the formula C6H6 has triggered many experiments and theoretical proposals. The correct ring struc­ H*H H ture, shown in 1 (see Figure 1), was assigned by Kekule after his H H celebrated dream of a snake attempting to swallow its tail. Some H (1) chemistry historians are debunking this bit about the dream. But Figure 1 Ktlkul. slrl/dure it may be too late; fact or fable, it is now part of chemistry folklore. Df benzene shDwn with dBlocallSlld 1t IIIBt:Irons. How many isomers are possible for C6H6, using the known rules about hydrocarbons? Many acyclic structures, such as Figure 2 5DmB 1IXpIII'i1flllll- dimethylbutadiene (2), readily come to mind. A large number of 1rI1/y known ell, IstJtnBrs. substituted 3-, 4- or 5- membered rings are also possible. Fulvene H H H H H (2) ~ ~ JiH H Fulvene (3) H (4) H H H H H H H H H Dewar H H H benzene (5) Benzvalene (6) Prismane (7) ---------~-------- 80 RESONANCE I February 1996 FEATURE i ARTICLE (3) is a famous example. Two 3-membered rings can also be H connected to form C H , as in isomer 4.
    [Show full text]
  • WO 2016/074683 Al 19 May 2016 (19.05.2016) W P O P C T
    (12) INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT) (19) World Intellectual Property Organization International Bureau (10) International Publication Number (43) International Publication Date WO 2016/074683 Al 19 May 2016 (19.05.2016) W P O P C T (51) International Patent Classification: (81) Designated States (unless otherwise indicated, for every C12N 15/10 (2006.01) kind of national protection available): AE, AG, AL, AM, AO, AT, AU, AZ, BA, BB, BG, BH, BN, BR, BW, BY, (21) International Application Number: BZ, CA, CH, CL, CN, CO, CR, CU, CZ, DE, DK, DM, PCT/DK20 15/050343 DO, DZ, EC, EE, EG, ES, FI, GB, GD, GE, GH, GM, GT, (22) International Filing Date: HN, HR, HU, ID, IL, IN, IR, IS, JP, KE, KG, KN, KP, KR, 11 November 2015 ( 11. 1 1.2015) KZ, LA, LC, LK, LR, LS, LU, LY, MA, MD, ME, MG, MK, MN, MW, MX, MY, MZ, NA, NG, NI, NO, NZ, OM, (25) Filing Language: English PA, PE, PG, PH, PL, PT, QA, RO, RS, RU, RW, SA, SC, (26) Publication Language: English SD, SE, SG, SK, SL, SM, ST, SV, SY, TH, TJ, TM, TN, TR, TT, TZ, UA, UG, US, UZ, VC, VN, ZA, ZM, ZW. (30) Priority Data: PA 2014 00655 11 November 2014 ( 11. 1 1.2014) DK (84) Designated States (unless otherwise indicated, for every 62/077,933 11 November 2014 ( 11. 11.2014) US kind of regional protection available): ARIPO (BW, GH, 62/202,3 18 7 August 2015 (07.08.2015) US GM, KE, LR, LS, MW, MZ, NA, RW, SD, SL, ST, SZ, TZ, UG, ZM, ZW), Eurasian (AM, AZ, BY, KG, KZ, RU, (71) Applicant: LUNDORF PEDERSEN MATERIALS APS TJ, TM), European (AL, AT, BE, BG, CH, CY, CZ, DE, [DK/DK]; Nordvej 16 B, Himmelev, DK-4000 Roskilde DK, EE, ES, FI, FR, GB, GR, HR, HU, IE, IS, IT, LT, LU, (DK).
    [Show full text]
  • Aromaticity Coal
    End Aromaticity Coal Coal as a Source of Benzene 1675 - Bituminous coal is distilled to form tars 1000 oC Coal gas + liquid + tar illuminating gas light oil tar H + CH 3.2 gal/ton pitch 2 4 60% benzene asphalt Faraday Faraday Isolates Bicarburetted Hydrogen 1825 - Michael Faraday isolates “bicarburetted hydrogen” (C12H6) from liquid residue in a cylinder of illuminating gas. [C = 6, H = 1] "One Christmas was so much like another, in those years around the sea-town corner now and out of all sound except the distant speaking of the voices I sometimes hear a moment before sleep, that I can never remember whether it snowed for six days and six nights when I was twelve or whether it snowed for twelve days and twelve nights when I was six." Michael Faraday "A Child's Christmas in Wales" --- Dylan Thomas (1791-1867) Mitscherlich The Preparation, Naming and Correct Formula of Benzene 1834 - Mitscherlich prepares benzene (C6H6) from benzoic acid by heating with CaO. Benzoic acid was prepared from gum benzoin resin from Styrax benzoin. Eilhard Mitscherlich (1794-1863) Kekule’s Theory Kekulé’s First Structure of Benzene 1865 - Proposes a cyclic structure for benzene with alternating single and double bonds 1890- Benzene Fest - Kekulé’s Dream August Kekulé (1829-1896) Ladenburg’s Objection Ladenburg’s Riposte Ladenburg, a former student of Kekulé’s, objects to his mentor’s formula for benzene because only one o-dibromobenzene is known, not two. Br Br Br Br Albert Ladenburg (1842 - 1911) Kekule Revised Kekule’s Response 1872 - Kekulé revises his theory, suggesting that the single bonds are changing places with the double bonds.
    [Show full text]
  • MCSCF Study of S1 and S2 Photochemical Reactions of Benzene
    J. Am. Chem. Soc, 1993,11S, 673-682 673 for correcting for the change in charge distribution, and the present known experimental data. In calculating AGo(soln) for the neutral approach represents the most accurate method of obtaining an radicals from eq 8, the solution free energies are partitioned as estimate of Eo(S).The resulting values of Eo(s)were -1.19, -1.73, the sum of hydrogen-bonding (AGo(HB)) and non-hydrogen- -1.05, and -0.94 V for methylamine, ethylamine, dimethylamine, bonding (AGo(NHB)) terms, and the latter is treated as a constant and trimethylamine, respectively. Likewise, utilizing the values which depends on the number of CH2units in the molecule. It of AGO(,) derived above, one can estimate that Eo(I)has values was argued that the difference in AGo(soln) between a-carbon of about -1.5, -1.9, -1.5, and -1.4 V for the same amines, re- radicals, R'R2NCR3H', and the parent molecules, R1R?NCR3H2, spectively. The large negative values of Eo(I)confirm the strong is less than 2 kJ mol-' and can be neglected. For the charged reductive power of these R1R2NCR3H'radicals. Previous esti- species, the difference between trimethylaminium ((CH,),N'+) mates of Eo(])in aqueous solution have been in the region of -1.0 and trimethylammonium ((CH3),NH+) could be derived from V.@ Equilibrium measurements of these quantities in water will experimental estimates of AGO(so1n) of the two species. The be very difficult because of the transitory nature of both the increase in magnitude of the solution free energy of (CH3),N'+ radicals and the iminium products.
    [Show full text]
  • A Procedure for Computing Hydrocarbon Strain Energies Using Computational Group Equivalents, with Application to 66 Molecules
    Swarthmore College Works Chemistry & Biochemistry Faculty Works Chemistry & Biochemistry 2020 A Procedure For Computing Hydrocarbon Strain Energies Using Computational Group Equivalents, With Application To 66 Molecules Paul R. Rablen Swarthmore College, [email protected] Follow this and additional works at: https://works.swarthmore.edu/fac-chemistry Part of the Organic Chemistry Commons Let us know how access to these works benefits ouy Recommended Citation Paul R. Rablen. (2020). "A Procedure For Computing Hydrocarbon Strain Energies Using Computational Group Equivalents, With Application To 66 Molecules". Chemistry. Volume 2, Issue 2. 347-360. DOI: 10.3390/chemistry2020022 https://works.swarthmore.edu/fac-chemistry/252 This work is licensed under a Creative Commons Attribution 4.0 License. This work is brought to you for free by Swarthmore College Libraries' Works. It has been accepted for inclusion in Chemistry & Biochemistry Faculty Works by an authorized administrator of Works. For more information, please contact [email protected]. Article A Procedure for Computing Hydrocarbon Strain Energies Using Computational Group Equivalents, y with Application to 66 Molecules Paul R. Rablen Department of Chemistry and Biochemistry, Swarthmore College, Swarthmore, PA 19081, USA; [email protected] Dedication: This paper is dedicated to Professor Bernd Giese on the occasion of his 80th birthday. It was a y pleasure and an honor to work with you on the question of electron conduction in peptides a few years ago. Received: 4 April 2020; Accepted: 27 April 2020; Published: 30 April 2020 Abstract: A method is presented for the direct computation of hydrocarbon strain energies using computational group equivalents. Parameters are provided at several high levels of electronic structure theory: W1BD, G-4, CBS-APNO, CBS-QB3, and M062X/6-31+G(2df,p).
    [Show full text]
  • Symmetry 2010, 2, 1745-1762; Doi:10.3390/Sym2041745 OPEN ACCESS Symmetry ISSN 2073-8994
    Symmetry 2010, 2, 1745-1762; doi:10.3390/sym2041745 OPEN ACCESS symmetry ISSN 2073-8994 www.mdpi.com/journal/symmetry Review n– Polyanionic Hexagons: X6 (X = Si, Ge) Masae Takahashi Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan; E-Mail: [email protected]; Tel.: +81-22-795-4271; Fax: +81-22-795-7810 Received: 16 August 2010; in revised form: 7 September 2010 / Accepted: 27 September 2010 / Published: 30 September 2010 Abstract: The paper reviews the polyanionic hexagons of silicon and germanium, focusing on aromaticity. The chair-like structures of hexasila- and hexagermabenzene are similar to a nonaromatic cyclohexane (CH2)6 and dissimilar to aromatic D6h-symmetric benzene (CH)6, although silicon and germanium are in the same group of the periodic table as carbon. Recently, six-membered silicon and germanium rings with extra electrons instead of conventional substituents, such as alkyl, aryl, etc., were calculated by us to have D6h symmetry and to be aromatic. We summarize here our main findings and the background needed to reach them, and propose a synthetically accessible molecule. Keywords: aromaticity; density-functional-theory calculations; Wade’s rule; Zintl phases; silicon clusters; germanium clusters 1. Introduction This review treats the subject of hexagonal silicon and germanium clusters, paying attention to the two-dimensional aromaticity. The concept of aromaticity is one of the most fascinating problems in chemistry [1,2]. Benzene is the archetypical aromatic hexagon of carbon: it is a planar, cyclic, fully conjugated system that possesses delocalized electrons. The two-dimensional aromaticity of planar monocyclic systems is governed by Hückel’s 4N + 2 rule, where N is the number of electrons.
    [Show full text]
  • V. Ramamurthy
    Updated on August 27, 2019 V. RAMAMURTHY Address: Department of Chemistry University of Miami, 1301 Memorial Drive Miami, FL 33124-0431 Tel: 305 284 1534 email: [email protected] Academic Training Undergraduate and Graduate Training: B. Sc., Chemistry, University of Madras, India 1966. M. Sc., Chemistry, Indian Institute of Technology, Madras, India, 1968. Ph. D., Chemistry, University of Hawaii, Honolulu, U.S.A., 1974, (R.S.H. Liu) Postdoctoral Fellow: University of Western Ontario, London, Canada, 1974-75, (P. de Mayo). Columbia University, New York, U.S.A., 1975-78, (N. J. Turro). Professional Appointments Assistant Professor, Department of Organic Chemistry, Indian Institute of Science, Bangalore, India, 1978-83. Associate Professor, Department of Organic Chemistry, Indian Institute of Science, Bangalore, India, 1983-88. Senior Research Scientist, Central Research and Development, Experimental Station, The du Pont Company, Wilmington, DE 19880-0328, 1987-1994. Bernard-Baus Professor of Chemistry, Tulane University, New Orleans, LA. July, 1994 – Dec 2004 Professor of Chemistry, University of Miami, Coral Gables, Jan 2005 – present. Administrative Appointments Chair of Chemistry, Tulane University, New Orleans, LA. July, 2003 – December 2004 Chair of Chemistry, University of Miami, Coral Gables, Jan 2005 – Sep 2013. Editor Senior Editor, Langmuir (ACS journal) 2008-current Editorial Board Editorial Board: Journal of Photochemistry: C (2001-current) Editorial Board: Journal of Photochemistry: A (2002-current) Editorial Board: Molecules
    [Show full text]
  • Durham E-Theses
    Durham E-Theses The photochemistry of highly uorinated pyridines Middleton, Roderick How to cite: Middleton, Roderick (1977) The photochemistry of highly uorinated pyridines, Durham theses, Durham University. Available at Durham E-Theses Online: http://etheses.dur.ac.uk/8331/ Use policy The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that: • a full bibliographic reference is made to the original source • a link is made to the metadata record in Durham E-Theses • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders. Please consult the full Durham E-Theses policy for further details. Academic Support Oce, Durham University, University Oce, Old Elvet, Durham DH1 3HP e-mail: [email protected] Tel: +44 0191 334 6107 http://etheses.dur.ac.uk UNIVERSITY OF DURHAM A THESIS entitled THE PHOTOCHEMISTRY OF HIGHLY FLUORINATED PYRIDINES Submitted by RODERICK MIDDLETON, B.Sc.(DUNELM) (Van Mlldert College) The copyright of this thesis rests with the author. No quotation from it should be published without his prior written consent and information derived from it should be acknowledged. A candidate for the degree of Doctor of Philosophy . 1977 To My Mother MEMORANDUM This work was carried out at the University of Durham between October 1973 and October 1976. It is the original work of the author unless indicated by reference and has no been submitted for any other degree.
    [Show full text]
  • Aromaticity and Conditions. Neutral and Charged Homo- and Hetero Aromatic Systems
    Aromaticity and Conditions. Neutral and charged homo- and hetero aromatic systems. Electrophilic aromatic substitution reaction its mechanism and basic cases. Substituent effects in electrophilic substitution reactions to the rate (reactivity), directing rules (regioselectivity). Electrophilic substitution reactions of five- and six-membered heteoaromatic compounds. Addition reactions. Reaction of aromatic hydrocarbons containing alkyl side chain, the benzyl type reactive intermediates. Some polycyclic aromatic hydrocarbons. Aromatic compounds and their classification Formally, cyclic compounds containing conjugated double bonds (and non-bonding electron pairs) - BUT itself is not a sufficient condition for aromaticity Aromatic compounds - characteristic chemical properties (in spite of unsaturation no addition reaction, BUT substitution reactions) + Anomalous NMR spectroscopy behaviour Classification 1. Homo aromatic compounds - carbocyclic (carbon atoms only!) 1.1. Monocyclic homo aromatic compounds - substituted benzene derivatives Mostly trivial or semi-trivial names (BUT the suffix is often misleading) benzene toluene xylene styrene phenol anisole aniline xylidine (o-, m-, p-) (o-, m-, p-) Some important groups 1.2. Polycyclic homo aromatic compounds 1 1.2.1. Isolated polycycles Ar-(C)n-Ar n = 0 Biphenyl and its derivatives E conjugation interaction between electron system of the two rings: coplanar nature? No! In gas and liquid phases decreasing overlap due to the van der Waals repulsion 90o 180o 270o o 360 between o, o'-hydrogens n ≥ 1 Aryl-substituted alkanes Consequence: Atrop isomerism Trityl cation (radical, anion) very stable. Reason: electron delocalization on 19 C Resonance structures of trityl cation 1.2.1. PAH: Polycyclic aromatic hydrocarbons: Condensed polycyclic - rings connected through two points (anellation points) Linearly condensed Angularly condensed naphthalene anthracene phenanthrene coronene Trivial names: special numbering: reason: highlighted position with different reactivity 2.
    [Show full text]