DOCSLIB.ORG

Week 1 Slides

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Week 1 Slides Adventures in Chemistry Instructor: Abi Oyeyemi Week 1 States of matter Boiling point, Melting point Atoms Types of Chemistry Hazards PPE Atoms consist of: Neutrons Protons Electrons 0 + - In In shells of atoms Nucleus States of Matter Solid, liquid, gas Week 2 Flame tests Orbitals Periodic table Octet Groups and Periods Experiment: Making a non-Newtonian Fluid Periodic Table Groups Each group tells how many electrons are in the outer shell. In chemistry, a group (also known as a family) is a column of elements in the periodic table of the chemical elements. The elements in each group have the same number of electrons in the outer orbital. Those outer electrons are also called valence electrons Periodic table 118 elements total 8 groups Group 1- Alkali metals Group 2- Alkali earth metals Group 7 –Halogens Group 8-Noble gases Elements structure Includes abbreviated name of element Atomic number-number of protons Always same number of protons and neutrons Mass number- average no. of neutrons and protons Amu: atomic mass units Isotopes Periodic table: Periods A period in the periodic table is a row of chemical elements. All elements in a row have the same number of electron shells/orbitals Week 3 More on the periodic table Electronic configuration Isotopes Chemical vs Physical changes Compounds vs Mixtures Ionic and Covalent bonds Demonstration Lava Lamp Activity: Making models Why do elements react? Octet, want a full outer shell How? By taking or giving electrons (ionic bonding) Or by sharing electrons (covalent bonding) Compounds- A compound is a substance formed when two or more chemical elements are chemically bonded together. Ionic vs Ionic bond- Ionic bonding is the complete transfer of valence electron(s) Covalent between atoms Bonds Covalent bonds- covalent bond, also called a molecular bond, is a chemical bond that involves the sharing of electron pairs between atoms Week 4 Polarity and Electronegativity Trends in the periodic table Drawing atoms, Ions, and Compounds Known Chemical Reactions Balancing equations Electronegativity This is the table that dictates whether elements bond through ionic bonding or covalent bonding If after subtraction of two elements electronegativities equal over 1.8 they bond ionically If under 1.8, they bond covalently Week 5 Reaction terms e.g. Aqueous, exothermic, endothermic, Chromatography with separation of pen inks Retention factor Balancing equations Acids and bases Solubility Dilute vs concentrated Red Cabbage Indicator Chromatography: How? Depends on what the mobile phase is and what the stationary phase is. Depends on the interactions between the sample and the 2 phases Polarity-unequal sharing of charge. Delta charges Like interacts with like, ie polar liquids interact with polar solids, meaning separation. Water is polar, paper is not. Reaction Conditions and Terminology Solution and its components Solute Solvent Solution Precipitation/ Solubility Soluble means able to be dissolved Solubility is the ability of a substance (the solute), to mix into a liquid (the solvent). In the e.g. previously shown…. Salt is seen to be soluble in water Once something is soluble and chemically becomes insoluble, this Is called a precipitate Concentrated vs Dilute solutions Acids: Proton donors Bases: proton acceptors Neutralisation A salt is defined as a substance that formed when the hydrogen ion from an acid is replaced with a metal or an ammonium ion Under 7 is acidic pH Scale Over 7 is basic or alkali 7 itself is neutral Litmus paper Red litmus paper turns blue in base Blue litmus paper turns red in acid Universal indicator paper pH is determined by changes in colors when sample reacts with indicator paper. Colour of the indicator paper is then compared to colour legend as seen Red cabbage indicator Homemade red cabbage indicator Acidic-pink Basic- Blue Red cabbage contains a water-soluble pigment called anthocyanin that changes color when it is mixed with an acid or a base. pH meters Modern and most accurate way of measuring pH Week 6 Recap of last 5 weeks Acids and bases Moles Avogadro’s number Atomic mass Hard water Moles Measure of units used in Chemistry/Biology/Physics Derived from amount of atoms in exactly 12.00 g of pure C12 Used as grams is not accurate, some elements denser than others Avogadro's number is 6.022x1023 This means in one mole of an element there are 6.022x1023 atoms Hard water Hard water is water that does not easily form a lather with soap forming scum It is caused by Ca2+ or Mg2+ ions dissolved in water (form flowing through soils) Equation behind Scum forming Eventually all Ca2+ ions removed and soap lathers Chemistry in the Environment Water Air 1. Screening 2. Flocculation Water 3. Sedimentation 4. Filtration treatment 5. Chlorination 6. Fluoridation 7. pH adjustment Water Treatment 3. 1.Screening 2. Flocculation Sedimentation •Water is •Addition of •Water slowly passed chemicals rises up and through a wire [Al2(SO4)3] to overflows and mesh help small •This allows •To remove particles other large debris clump sediments to together settle to the •May affect bottom of the taste tank Water Treatment 4.Filtration 5.Chlorination 6. Fluoridation 7. pH adjustment • Filtering of the • Addition of • Addition of • Adjustment of water through Chlorine to kill fluorine pH to 7.2 densely harmful compounds • If too acidic packed beds bacteria in the e.g. sodium calcium of sand(like water fluoride to hydroxide is filter paper) water to added reduce tooth • If too basic decay add dilute • Fluoride ions sulfuric acid or strengthen CO2 enamel of teeth • Too much fluorine can cause staining of teeth Air Composition of air Gas Percentage in air Oxygen 21% Nitrogen 78% Carbon Dioxide 0.03% Noble gases Less than 1% Water vapour Varies Oxygen Most reactive gas in air Used with ethyne gas in blow torches for welding (exothermic reaction) Used in steel making (again exothermic reaction) Hospitals Nitrogen gas Nitrogen Group 5 element Two nitrogen atoms covalently bonded together chemically each sharing 3 electrons Unreactive (full octet) Shares 3 electrons Used to keep food fresh, packets of crisps Used to make ammonia NH3 for fertilisers Liquid nitrogen: Freeze foods Remove warts Separation of air to form pure oxygen and nitrogen Liquefaction. Air is liquefied by the Linde process Air is alternately compressed, cooled, and allowed to expanded, Water and CO2 removed in the separator Fractional distillation used to separate out oxygen as a liquid and nitrogen as a gas. Photosynthesis Respiration Aerobic (in the presence of oxygen), how we get energy from our food Anaerobic Respiration (in the absence of oxygen), how we get energy when we are exercising Lactic acid is what makes your muscles ache after intense exercise Acid and carbonate rocket Demonstration Element fact sheet Assignment Diagram: Bohr structure Electronic configuration e.g. if I was doing calcium, 2,8,8,2 so no of electrons in each shell Number of electrons, protons, and neutrons, Use in everyday life or if dangerous or radioactive, its use in Science field, Traits, boiling point, melting point, reactivity How and when and by whom was discovered or isolated Interesting facts Also available on Website EXPERIMENTS DONE IN CLASS AND TEMPLATE LAB REPORT IN VIDEOS INSTRUCTIONS FOR ELEMENT (PARENT SUPERVISION AT ALL FACT SHEET TIMES).
Load more

Recommended publications
  • Chemistry of Superheavy Elements Matthias Schädel*
    Reviews M. Schädel DOI: 10.1002/anie.200461072 Superheavy Elements Chemistry of Superheavy Elements Matthias Schädel* Keywords: Dedicated to Professor Günter Herrmann atom-at-a-time chemistry · periodic on the occasion of his 80th birthday table · relativistic effects · superheavy elements · transactinides Angewandte Chemie 368 www.angewandte.org 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim Angew. Chem. Int. Ed. 2006, 45, 368 – 401 Angewandte Superheavy Elements Chemie The number of chemical elements has increased considerably in the From the Contents last few decades.Most excitingly, these heaviest, man-made elements at the far-end of the Periodic Table are located in the area of the long- 1. Introduction and Historical Remarks 369 awaited superheavy elements.While physical techniques currently play a leading role in these discoveries, the chemistry of superheavy 2. Nuclear Aspects 372 elements is now beginning to be developed.Advanced and very sensitive techniques allow the chemical properties of these elusive 3. Atom-at-a-Time Chemistry 374 elements to be probed.Often, less than ten short-lived atoms, chemi- 4. Objectives for Superheavy cally separated one-atom-at-a-time, provide crucial information on Element Chemistry 375 basic chemical properties.These results place the architecture of the far-end of the Periodic Table on the test bench and probe the 5. Experimental Techniques 376 increasingly strong relativistic effects that influence the chemical 6. Chemical Properties 380 properties there.This review is focused mainly on the experimental work on superheavy element chemistry.It contains a short contribu- 7. Summary and Perspectives 394 tion on relativistic theory, and some important historical and nuclear aspects.
    [Show full text]
  • Syllabus Outline
    Syllabus Syllabus outline Syllabus component Recommended teaching hours SL HL Core 95 1. Stoichiometric relationships 13.5 2. Atomic structure 6 3. Periodicity 6 4. Chemical bonding and structure 13.5 5. Energetics/thermochemistry 9 6. Chemical kinetics 7 7. Equilibrium 4.5 8. Acids and bases 6.5 9. Redox processes 8 10. Organic chemistry 11 11. Measurement and data processing 10 Additional higher level (AHL) 60 12. Atomic structure 2 13. The periodic table—the transition metals 4 14. Chemical bonding and structure 7 15. Energetics/thermochemistry 7 16. Chemical kinetics 6 17. Equilibrium 4 18. Acids and bases 10 19. Redox processes 6 20. Organic chemistry 12 21. Measurement and analysis 2 Option 15 25 A. Materials 15 25 B. Biochemistry 15 25 C. Energy 15 25 D. Medicinal chemistry 15 25 20 Chemistry guide Syllabus outline Syllabus component Recommended teaching hours SL HL Practical scheme of work 40 60 Practical activities 20 40 Individual investigation (internal assessment—IA) 10 10 Group 4 project 10 10 Total teaching hours 150 240 The recommended teaching time is 240 hours to complete HL courses and 150 hours to complete SL courses as stated in the document General regulations: Diploma Programme (2011) (page 4, Article 8.2). Chemistry guide 21 Syllabus Approaches to the teaching of chemistry Format of the syllabus The format of the syllabus section of the group 4 guides is the same for each subject physics, chemistry and biology. This new structure gives prominence and focus to the teaching and learning aspects. Topics or options Topics are numbered and options are indicated by a letter.
    [Show full text]
  • Inorganic Chemistry-Ii
    BSCCH- 201 B. Sc. II YEAR INORGANIC CHEMISTRY-II SCHOOL OF SCIENCES DEPARTMENT OF CHEMISTRY UTTARAKHAND OPEN UNIVERSITY BSCCH-201 INORGANIC CHEMISTRY-II SCHOOL OF SCIENCES DEPARTMENT OF CHEMISTRY UTTARAKHAND OPEN UNIVERSITY Phone No. 05946-261122, 261123 Toll free No. 18001804025 Fax No. 05946-264232, E. mail [email protected] htpp://uou.ac.in Board of Studies Prof. Govind Singh Prof. B. S. Saraswat Director, School of Sciences Professor Chemistry Uttarakhand Open University Department of Chemistry School of Sciences, IGNOU, New Delhi Prof S. P. S. Mehta Prof. D. S. Rawat Professor Chemistry Professor Chemistry Department of Chemistry Department of Chemistry DSB Campus, Kumaun University Delhi University, Delhi Nainital Dr. Charu C. Pant Programme Coordinator Department of Chemistry School of Sciences, Uttarakhand Open University Haldwani, Nainital Programme Coordinators Dr. Shalini Singh (Assistant Professor) Department of Chemistry School of Sciences, Uttarakhand Open University Haldwani, Nainital Unit Written By Unit No. 1. Dr. K. S. Dhami (Ret. Proff.) 01, 02, 03, 04 & 05 Department of Chemistry D.S.B. Campus, Kumaun University Nainital 2. Dr. Geeta Tiwari 06, 07, 08 & 09 Department of Chemistry D.S.B. Campus, Kumaun University Nainital Course Editor Prof. B.S. Saraswat Professor of Chemistry (Retd.) School of Sciences, Indira Gandhi National Open University (IGNOU), Maidan Garhi, New Delhi - 110068 Title : Inorganic Chemistry II ISBN No. : 978-93-90845-04-0 Copyright : Uttarakhand Open University Edition : 2021 Published by : Uttarakhand
    [Show full text]
  • Page 1 Stockland Green School
    Stockland Green School Q1. The periodic table on the Data Sheet may help you to answer these questions. (a) Part of the periodic table is shown below. The letters are not the symbols of the elements. Choose your answers only from the letters shown in the periodic table above. Which letter, A, B, C, D, E or F, represents (i) aluminium (1) (ii) a Group 5 element (1) (iii) an alkali metal (1) (iv) the element with atomic (proton) number of 47 (1) Page 1 Stockland Green School (v) an element with seven electrons in its outer shell? (1) (b) The table shows the boiling points of the Group 7 elements. The elements are arranged in alphabetical order. Group 7 element Name Symbol Boiling point in °C Astatine At 337 Bromine 58 Chlorine Cl -34 Fluorine F -188 Iodine I 184 (i) The symbol for bromine is missing from the table. What is the symbol for bromine? Symbol = .............................. (1) (ii) Arrange these elements in order of decreasing boiling point. The first one and the last one have been done for you. At ............ ............ ............ F Highest boiling point Lowest boiling point (1) (c) The table shows some statements about Group 7 elements. Page 2 Stockland Green School Tick ( ) the two correct statements. Tick ( ) They are halogens. They are metals. They become less reactive down Group 7. They are compounds. (2) (Total 9 marks) Q2. The elements in Group 1 are known as the alkali metals. Which three of the following are properties of alkali metals? Place a tick ( ) in the box against each correct property.
    [Show full text]
  • The Electronic Structure of the Atoms of Five Elements Are Shown in the Figure Below. the Letters Are Not the Symbols of The
    www.tutorzone.co.uk The electronic structure of the atoms of five elements are shown in the figure below. 1 The letters are not the symbols of the elements. Choose the element to answer the question. Each element can be used once, more than once or not at all. Use the periodic table to help you. (a) Which element is hydrogen? Tick one box. A B C D E (1) (b) Which element is a halogen? Tick one box. A B C D E (1) (c) Which element is a metal in the same group of the periodic table as element A? Tick one box. A B C D E (1) Page 1 of 99 www.tutorzone.co.uk (d) Which element exists as single atoms? Tick one box. A B C D E (1) (e) There are two isotopes of element A. Information about the two isotopes is shown in the table below. Mass number of the isotope 6 7 Percentage abundance 92.5 7.5 Use the information in the table above above to calculate the relative atomic mass of element A. Give your answer to 2 decimal places. ............................................................................................................................. ............................................................................................................................. ............................................................................................................................. ............................................................................................................................. ............................................................................................................................
    [Show full text]
  • Lawrence Berkeley Laboratory UNIVERSITY of CALIFORNIA J • ' L·' -·
    Lawrence Berkeley National Laboratory Recent Work Title Chemistry of the Transactinide Elements Permalink https://escholarship.org/uc/item/0pc2v1nz Author Hoffman, D.C. Publication Date 1990-10-01 eScholarship.org Powered by the California Digital Library University of California LBL-29815 Lawrence Berkeley Laboratory UNIVERSITY OF CALIFORNIA j • ' l·' -· Presented at the Robert A. Welch Foundation Conference on Chemical Research XXXIV, Fifty Years with Transuranium Elements, Houston, TX, October 22-23, 1990, and to be published in the Proceedings Chemistry of the Transactinide Elements D.C. Hoffman October 1990 -nn--- 0 ...... r -<. ;; 0 f) me zD 1-' ~ !ll n lj) cTO lj) If) 1J A"Ul ;..'I -< --- ~ I Ill 1-' \ a. I.Ci. (Jl oSI r r ttl ..... r crn ! ;; 0 r(, !li"O ...0 ;;-..:: ():) '< ....... m tn Prepared for the U.S. Department of Energy under Contract Number DE-AC03-76SF00098 DISCLAIMER This document was prepared as an account of work sponsored by the United States Government. While this document is believed to contain correct information, neither the United States Government nor any agency thereof, nor the Regents of the University of California, nor any of their employees, makes any warranty, express or implied, or assumes any legal responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by its trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof, or the Regents of the University of California.
    [Show full text]
  • Chalcogenocarboxylic Acids
    Top Curr Chem (2005) 251: 1–12 DOI 10.1007/b101005 © Springer-Verlag Berlin Heidelberg 2005 Chalcogenocarboxylic Acids Osamu Niyomura1 · Shinzi Kato2 () 1 Division of Chemistry, Center for Natural Sciences, College of Liberal Arts and Sciences, Kitasato University, Kitasato, Sagamihara, Kanagawa 228–8555, Japan [email protected] 2 Department of Applied Chemistry, School of Engineering, Chubu University, Matsumoto-Cho, Kasugai, Aichi, 487–8501, Japan [email protected] 1 Introduction . 2 2 Syntheses . 3 2.1 Monochalcogenocarboxylic Acids . 3 2.2 Dichalcogenocarboxylic Acids . 3 3 Structures and Physical Properties . 4 3.1 Spectroscopic Studies . 4 3.2 X-ray Structural Analyses . 6 3.3 Theoretical Studies . 7 4Reactions . 8 4.1 Thiocarboxylic Acids . 8 4.2 Dithiocarboxylic Acids . 10 4.3 Seleno- and Tellurocarboxylic Acids . 10 References . 11 Abstract Although thio- and dithio-carboxylic acids have been extensively studied for some time now, research into other chalcogenocarboxylic acids – containing selenium and tel- lurium – has only blossomed over the last decade. Monochalcogenocarboxylic acids exist as fast tautomeric equilibrium mixtures of chalcogenol and chalcogenoxo forms. The chal- cogenol form is the predominant species in solid state and nonpolar solvents. In contrast, in polar solvents at low temperature, the acids predominantly exist in the chalcogenoxo form. Syntheses of heavier dichalcogenocarboxylic acids have only been attempted very recently.This chapter presents the results from recent studies of chalcogenocarboxylic acids, their syntheses, structures and reactions. Keywords Chalcogenocarboxylic acids · Chalcogenol form · Chalcogenoxo form · Carboxylic acids · Chalcogens 2 O. Niyomura · S. Kato 1 Introduction Carboxylic acids are one of the most fundamental and important groups of compounds in organic chemistry.
    [Show full text]
  • Rutherfordium (Element 104)
    Chemical and Nuclear Properties of Rutherfordium (Element 104) Christian D. Kacher Ph. D. Thesis October 30,1995 Department of Chemistry University of California, Berkeley and Nuclear Science Division Lawrence Berkeley National Laboratory University of California Berkeley, CA 94720 This work was supported in part by the Qirector, Office of Energy Sciences, Chemical Sciences Division of the US. Department of Energy under Contract DE-AC03-76SF00098 Portions of this document may be illegible in elmnic image products. Images are produced from the best available original dOCUmeIlL Abstract Chemical and Nuclear hoperties of Rutherfordium (Element 104) bY Christian D. Kacher Doctor of Philosophy in Chemistry University of California at Berkeley Professor Darleane C. Hoffman, Chair The chemical properties of rutherfordium (Rf) and its group 4 homologs were studied by sorption on glass support surfaces coated with cobalt(lI)femcyanide and by solvent extraction with tributylphosphate (TBP)and triisooctylamine (TIOA). The surface studies showed that the hydrolysis trend in the group 4 elements and the pseudogroup 4 element, Th, decreases in the order Rf>Zr=Hf>Th. This trend was attributed to relativistic effects which predicted that Rf would be more prone to having a coordination number of 6 than 8 in most aqueous solutions due to a destabilization of the 6d5n shell and a stabilization of the 7p1~shell. This hydrolysis trend was confirmed in the TBP/HBr solvent extraction studies which showed that the extraction trend decreased in the order ZmHf>Rf?Ti for HBr, showing that Rf and Ti did not extract as well because they hydrolyzed more easily than Zr and Hf.
    [Show full text]
  • Tableau Périodique Des Éléments Tableau Périodique Des Éléments Version 1.0 (Dernière Mise À Jour : 2019-04-11)
    - Institut de l'information scientifique et technique - Tableau périodique des éléments Tableau périodique des éléments Version 1.0 (dernière mise à jour : 2019-04-11) Ce thésaurus trilingue (français, anglais, espagnol) regroupe les 118 éléments chimiques du tableau périodique reconnus par l'IUPAC (https://iupac.org/). Il est aligné avec ChEBI (https://www.ebi.ac.uk/chebi/), wikidata (https://www.wikidata.org/), wikipédia (https:// www.wikipedia.org/), DBpedia (https://wiki.dbpedia.org/). Une version anglaise de cette ressource est également disponible. La ressource est en ligne sur le portail terminologique Loterre : https://www.loterre.fr Légende • Syn : Synonyme. • → : Renvoi vers le terme préférentiel. • EN : Préférentiel anglais. • ES : Préférentiel espagnol. • TS : Terme spécifique. • TG : Terme générique. • CS : Catégorie sémantique. • URI : URI du concept (cliquer pour le voir en ligne). • EQ : Alignement. Cette ressource est diffusée sous licence Creative Commons Attribution 4.0 International : TABLE DES MATIÈRES Index alphabétique 4 Entrées terminologiques 5 Liste des entrées 61 Arborescence 65 Collections 73 Index alphabétique de actinide à azote p. 8 -8 de baryum à brome p. 9 -10 de cadmium à curium p. 11 -13 de darmstadtium à dysprosium p. 14 -14 de einsteinium à europium p. 24 -24 de famille d'éléments à francium p. 26 -26 de gadolinium à groupe p. 27 -28 de hafnium à hydrogène p. 30 -30 de indium à iridium p. 31 -31 de krypton à krypton p. 32 -32 de lanthane à lutécium p. 33 -34 de magnésium à moscovium p. 35 -38 de néodyme à non métal p. 39 -41 de oganesson à oxygène p.
    [Show full text]
  • Science 9 Review: Answers Part 1 1
    Science 9 Review: Answers Part 1 1. You should tie back loose clothing, wear safety goggles, wear closed-toe shoes, and tie back long hair. 2. This is a chemical change, as a gas and a new substance was formed. 3. Chart should be similar to chart on page 103 in the student book. 4. Physical properties of ice cream include: its colour, melts around 0°C, hardness – soft, density and conductivity – none. 5. Answers will vary, but should show evidence of being able to describe the differences between physical and chemical changes. Students should also indicate that knowing about these changes helps one to find potential applications for these changes. For example, baking soda is used in cooking because the carbon dioxide gas can help cakes and bread rise. 6. Plaster of Paris 7. Dalton viewed the atom as a solid ball—like a billiard ball. Bohr viewed the atom as electrons orbiting the nucleus in specific orbits. 8. Lavoisier was “the father of chemistry” because of his experimental and theoretical work, which included devising a naming system for chemicals. 9. Na 11 23.0 Br 35 83.8 S 16 32.1 10. Mendeleev’s work on the periodic table represented his contribution, which was a continuation of the work of others. Students should indicate that Mendeleev’s work was the result of his creativity, hard work, and inspiration, but the basis of his work came from the efforts of previous researchers. Mendeleev grouped the elements according to a pattern. 11. a) ionic b) molecular c) ionic 12.
    [Show full text]
  • Synthesis, Crystal Structures and Spectroscopic Properties Of
    Synthesis, Crystal Structures and Spectroscopic Properties of RbBaTaS4 and K2BaTa2S11 Yuandong Wu and Wolfgang Bensch Institut f¨ur Anorganische Chemie, Universit¨at Kiel, Max-Eyth-Straße 2, 24118 Kiel, Germany Reprint requests to Prof. W. Bensch. Fax: +49-431-880-1520. E-mail: [email protected] Z. Naturforsch. 2010, 65b, 1219 – 1228; received April 6, 2010 Single crystals of RbBaTaS (1)andK BaTa S (2) were obtained from the reactions of Ta, with 4 2 2 11 ◦ in situ formed fluxes of A2S3 (A = K, Rb), BaS, and S at 500 C. Compound 1 crystallizes in the or- thorhombic space group Pnma with a = 9.3286(5), b = 7.0391(4), c = 12.4365(7) A,˚ V = 816.6(1) A˚ 3, Z = 4. Compound 2 crystallizes in the monoclinic space group P21/c with a = 14.5280(10), b = ◦ 3 12.6347(7), c = 17.5148(12) A,˚ β = 94.744(8) , V = 3203.9(4) A˚ , Z = 4. The structure of RbBaTaS4 3− + 2+ 2+ (1) consists of isolated tetrahedral [TaS4] anions and Rb and Ba cations. The Ba cations are surrounded by nine sulfur atoms forming distorted tricapped trigonal prisms, whereas the Rb+ cations are in an irregular environment of ten sulfur atoms. The structure of K2BaTa2S11 (2) con- 2+ + sists of two different dinuclear [Ta2S11] units which are separated by Ba and K cations. The 2− 2− 2 1 Ta atoms are coordinated by S2 and S ligands according to the mode [Ta2(µ2-S)(µ2-η ,η - S ) (η2-S ) (S) ]4−. Each Ta atom is surrounded by seven sulfur ions forming strongly distorted 2 2 2 2 2 + pentagonal bipyramids.
    [Show full text]
  • Alkoxide Complexes of Rhenium, Niobium and Tantalum
    Alkoxide complexes of Rhenium, Niobium and Tantalum Olesya A. Nikonova Faculty of Natural Resources and Agricultural Sciences Department of Chemistry Uppsala Licentiate Thesis Swedish University of Agricultural Sciences Uppsala 2009 ISBN 978-91-86197-17-9 © 2009 Olesya A. Nikonova, Uppsala Print: SLU Service/Repro, Uppsala 2009 Alkoxide complexes of Rhenium, Niobium and Tantalum Abstract This thesis describes two major methods for preparation of new mono-, bi- and trimetallic complexes on the basis of Rhenium, Niobium and Tantalum: (1) - the electrochemical method for the synthesis of Re4O4(OEt)12 and (2) - the interaction of Rhenium heptoxide, Re2O7, with alkoxo-derivates of Niobium and/or Tantalum, M2(OR)10 for the synthesis of bi- and trimetallic complexes of common formula (M1-xM'x)4O2(OR)14(ReO4)2 (M = Nb; M' = Ta; R = Me, Et), where x = 0– 1. The structures of these complexes were determined by single-crystal X-ray diffraction. The products were also characterized by IR, NMR and X-ray powder diffraction. The influence of the increasing ligand size on the solubility and stability of the complexes Re4O4(OEt)12 and M4O2(OR)14(ReO4)2 (M = Nb, Ta; R = Me, Et) has been established. The effect of the ligand and metal ion ratio on the conditions and the chemical composition of the products of thermal treatment have been investigated. Nanosized Rhenium metal particles (approximately 3 nm in diameter) were obtained from Re4O4(OEt)12 by thermal decomposition in inert atmosphere at as low temperature as 380 °C. Semi-ordered macro porous monoliths with the pore size in the range 100 – 250 nm, with the crystal structure related to the block structures of the L-modification of Ta2O5, were produced from trimetallic complexes of the common formula (Nb1- xTax)4O2(OMe)14(ReO4)2 (x = 0.3, 0.5, 0.7) via thermal decomposition in air at the temperatures ≤ 1000 °C.
    [Show full text]