Home >Documents >ELECTROCHEMICAL AND SPECTROSCOPIC STUDIES OF SOME j ... aqueous potassium salt into benzene and...

ELECTROCHEMICAL AND SPECTROSCOPIC STUDIES OF SOME j ... aqueous potassium salt into benzene and...

Date post:16-Jan-2020
Category:
View:3 times
Download:1 times
Share this document with a friend
Transcript:
  • AD-A172 916 ELECTROCHEMICAL AND SPECTROSCOPIC STUDIES OF SOME j TUNGSTOCUPRATE NETEROPO (U) AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH C M KELLY MAR 86

    UNCLASSIFIED AFIT/CNR-78T BF/G21/2 NL

    EhhhhhhhhhhhhE EhhhhhhhhhhhhIl .EhhhhmhhhhhhhE EhhhhhhhhhhhhEl

  • Q .

    ~~~ 1.0L2

    MICROCOPY RESOLUTION TEST CHART NATIONAL BUREAU OF STANDARDS- 1963-A

  • SECURITY CLASSIFICATION OF THIS PAGE (When Dolta Etervd).

    REPORT DOCUMENTATION PAGE READ INSTrRUCTIONS 131E.1ORE COMPLETING FORM

    1. REPORT NUMBER 2. GOVT ACCESSION No. 3. RECIPIENT'S CATALOG NUMBER

    AFIT/CI/NR 86-178TI 4. TITLE (mid Subtitle) 5. TYPE OF REPORT & PERIOD COVERED

    Electrochemical and Spectroscopic Studies of THESIS/d~iiiiif~N Some Tungstocuprate Heteropolyanions in Polar

    and Nonpolar Solvents. Reaction with 6. PERFORMING 01G. REPORT NUMBER

    Superoxi de. 7. AU THOR(s) 8. CONTRACT OR GRANT NUMBER(s)

    Christine M. Kelly

    9 PERFORMING ORGANIZATION NAME AND ADDRESS 10. PROGRAM ELEMENT. PROJECT, TASK AREA 8 WORK UNIT NUMBERS

    AFIT STUDENT AT: Georgetown University

    II. CONTROLLING OFFICE NAME AND ADDRESS 12. REPORT DATE

    CD 1986 13 NUMBER OF PAGES

    84 4 MONITORING AGENCY NAME & ADDRESS(iI diffeernt from Controllng Of fice) IS. SECURITY CLASS. (of this report)

    IN UNCLASS 15s. DECLASSIFICATION DOWNGRADING

    SCHEDULE

    S 16. DISTRIBUTION STATEMENT (of this Report)

    APPROVED FOR PUBLIC RELEASE; DISTRIBUTION UNLIMITED

    17. DISTRIBUTION STATEMENT (0f the abstract entered in Bflock 20. if different from Report)

    IS. SUPPLEMENTARY NOTES ~~*R~ r.J APPROVED FOR PUBLIC RELEASE: IAW AFR 190-1 INI

    D an for Research and Professional Development AFIT/NR

    19. KEY WORDS (Continue or. reverse side it necessary and identify by block nm

    20. ABSTRACT (Continue on rovers& side If necessary and Identify by bloc~k number) L x

    ATTACHED ...

    DD IJAN 73 1473 ED;TION OF I NOV 95 IS OBSOLETE

    SECURITY CLASSIFICATION OF THIS PAGEE (I 4 i.cn D.ta Entered)

    i~e -. . . .IN Gp

  • ABSTRACT

    his thesis describes some of the chemistry of

    copper(II) heteropolyoxotungstate anions viewed as

    inorganic analogues of copper porphyrins.

    The heteropolytungstate anions, [XW IOl 9 Cu(II)-O ]n-

    (X = Si, B, Zn) were synthesized and isolated as the

    potassium salts. Electrochemical investigation of these

    anions at pH 2.2, 4.7, and 6.0 revealed no evidence of

    oxidation to Cu(III) derivatives. Organic solutions of

    the Si heteropolyanion were generated by extracting the

    aqueous potassium salt into benzene and toluene using

    tetraheptylammonium bromide. The (BJ)N)HSiW11Q39 Cu (I)

    salt (soluble in acetonitrile) was isolated and

    characterized by analysis, potentiometric titration and

    ESR spectroscopy.

    In the polar and nonpolar non-aqueous solvents, the

    water molecule coordinated to the Cu is lost, as shown by

    changes in ESR and optical spectra. Cyclic voltammograms

    of I and its deprotonated form (II) in acetonitrile showed

    no copper oxidation feature. Treatment of solutions of II

    in toluene or acetonitrile with Brf or O at ambient and

    low temperatures did not result in oxidation or oxygen-.

    - 86 jO 10 09

  • ation of the heteropolyanion. Corresponding treatment

    with superoxide anion, 0 , led to new ESR-active pro-

    ducts .

    * 72

    A-

  • GEORGETOWN UNIVERSITY GRADUATE SCHOOL

    U,

    The dissertation of-.Cap.t.. Christine M. Kelly entitled

    Electrochemical and Spectroscopic Studies of Some

    Tungstocuprate Heteropolyanions in Polar and Nonpolar Solvents. Reaction with Superoxide.

    submitted to the department of ...... Chemistry ... ............ .............. in partial

    Master of Sciencefulfillment of the requirements for the degree of ...... ........ . . .................................... in the Graduate School of Georgetown University has been read and approved by the

    Committee:

    Headof *eme

    °Date

  • ELECTROCHEMICAL AND SPECTROSCOPIC STUDIES OF SOME

    TUNGSTOCUPRATE HETEROPOLYANIONS IN POLAR AND

    NONPOLAR SOLVENTS. REACTION WITH SUPEROXIDE.

    A Thesis submitted to the Faculty of the

    Graduate School of Georgetown University in partial fulfillment of the requirements for the

    degree of Master of Science

    By

    Christine M. Kelly, Capt, USAF Miami University, Oxford, Ohio, (1977) B.S.

    Washington, DC March, 1986

  • Dedicated to my husband and son

    Darby J. Kelly, Major, USAF

    S. Michael Kelly

  • ACKNOWLEDGMENTS

    The author gratefully acknowledges the United States

    Air Force for providing the opportunity , both in terms of

    time and dollars, to earn a Master's degree. However,

    without the emotional support and domestic help of her

    husband and son, the time and effort required to earn this

    degree would not have been available.

    The author express profound gratitude to her research

    and thesis advisor, Dr. Michael Pope for defining a chal-

    lenging research effort and providing the technical guida-

    nce, expertise and encouragement needed to see the project

    to successful completion.

    The author thanks each member of the research group

    for his/her invaluable tutorials on both the theoretical

    and practical aspects of heteropolyanions and instrumen-

    tation. For assistance in the electrochemical experi-

    ments, the author thanks Fr. M. Manimala.

    Dr. Louis Baker is thanked for his reading of the

    thesis and many knowledgable comments.

    Thanks are extended to Mr. William Craig and Mr. Fred

    Henzler for their assistance in keeping the instrumenta-

    tion in good working condition, often on emergency notice.

    - iii -

    ' ,. 4.,,9. -

  • The author thanks Mrs. Ann Pope, Dr. Violet Simmons,

    and Mrs. Peg O'Rourke for their invaluable assistance and

    understanding ears.

    And for final typing and corrections, thanks are given

    to Mrs. Iren Hogye and Mrs. Kay Bayne.

    - iv-

    9j( j'e eA,

  • TABLE OF CONTENTS

    Page

    ABSTRACT

    ACKNOWLEDGMENTS ..................................... iii

    TABLE OF CONTENTS .......... o ....... .. . .............. v

    LIST OF TABLES ...................................... viii

    LIST OF FIGURES ..................... ........ . xi

    LIST OF FORMULA ABBREVIATIONS ....................... xiii

    CHAPTER I. INTRODUCTION ........................... 1

    CHAPTER II. EXPERIMENTAL ....... ................... 10

    A. Vibrational Spectra ..................... 10

    B. Electronic Spectra ...................... 10

    C. Electrochemistry ....................... 0 10

    1. Cyclic Voltammetry ................... 10

    2. Controlled Potential Electrolysis .... 12

    D. pH and Electrical Potential

    Measurements .......... 0 ..... ......... . 13

    E. Electron Spin Resonance ................. 14

    CHAPTER III. RESULTS AND DISCUSSION ................ 16

    1. Preparation of Copper(II) Heteropolyoxo-

    anions in Aqueous and Non-Aqueous Solvents... 16

    A. Reagents and Materials ................... 17

    B. Synthesis of Potassium Salts of Copper(II)

    Compounds in Water ........................ 20

    m-v

  • Page

    1) Potassium a-undecatungstosilico-

    cuprate ......................... .. 20

    2) Potassium a-undecatungstoboro-

    cuprate ........ ................... 20

    3) Potassium a-undecatungstozinc-

    cuprate ..................... .... ... . 24

    C. Generation of a-undecatungstosilico-

    cuprate Salts in Organic Solvents .......... 25

    1) Non-polar Solvents ..................... 25

    a) Extraction into Toluene ........... 25

    b) Extraction into Benzene ............ 26

    2) Polar Solvents ............ ............. 26

    a) Precipitation of TBA Salt from

    Aqueous Solution .................... 26

    2. Aqueous Chemistry .............. ............... . 30

    A. Electrochemistry ........................... 30

    B. Electron Spin Resonance .................... 39

    3. Non-Aqueous Chemistry ........................ 46

    A. Electronic Absorption Spectra

    (Near-IR) .................................. 46

    B. Electrochemistry ........................... 49

    C. Electron Spin Resonance .................... 54

    - vi -

  • Page

    D. Reaction with 02 ...................... 5

    E . Reaction with Br 2 . ... ................. 6

    F. Reaction with Superoxide (02 )............ 66

    REFERENCES .................... ** *** ............. 80

    -vii-

  • LIST OF TABLES

    TABLE Page

    1. Electronic Absorption Maxima of Cu(II)

    in Tungstate Anions as K+ Salts in

    Acetate Buffer - Near-IR ................ 23

    2. Voltammetric Data for Copper and Tungsten

    Reductions in XWIICu(II) Anions in

    Various Buffers ....................... 35

    3. ESR Parameters for K+ Salts of

    XW 1 1 Cu(II)-OH2 in Aqueous Glycerol ....... 41

    4. Electronic Absorption Maxima of Cu(II) in

    Protonated and Deprotonated SiW 1 1 Anions

    in Organic Solvent

of 106

Click here to load reader

Embed Size (px)
Recommended