'.

PREPARATION. STRUCTURAL CHARACTERIZATION AND

, ELECTRICAL PROPERTIES OF S()lE POLYATOMIC

CATIONS OF MERCURY

I

Ir

::.

I

!;

\

1

PREPARATION. STRUCTURAL CHARACTERIZATION AND

ELECTRICAL PROPERTIES OF SOME POLYATCMIC

CATIONS OF MERCURY

by

BRENT D. CUTFORTH

.,

A ThesisSubmitted to the Faculty of Graduate Studies

in Partial Fulfilment of the Requirementsfor the Degree

Doctor of Philosophy

McMaster University

October 1975

..

I if) BRENT D. CUT~RTH 1977

MCMASTER UNIVERSITYHamilton, Ontario

..,.~.

i

DOCTOR' OF PHILOSOPHY (1975) II(Chemistry)

i .ii

TITLE: Preparation, Structural Characterization and ElectricalProperties of Some iPo1yatomic Cations of Mercury

I

IAUTHOR: Brent D.• Cutforth IB.Sc. (University of Victoria)

I

• SUPERVISOR: Professor R.Jf Gillespie

INUMBER OF PAGES: xi i , 13'4

/

/

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ABSTRACT

The preparation of a number of new compounds containing mercury

in formally low oxidation states is reported. The preparations are

described and Raman s[iectra are reported. for H9Z(AsF6)Z's?'Z',

H9 Z(AsF6)Z' H9Z(SbZF11 )Z'SOZ' H9Z(SbF6)Z' SOZ' H9Z(SbF6)Z' and H9Z(S03F)Z'

All of the mercurous salts have been prepared for the first time, The

preparatioOSof Hg3(AsF6)Z and H93(SbzFlf)z' both of which contain .the

H93ZTcation,are presented. The. H94

Z+ cation, which has not been

identified previou~ly, is present in Hg4(AsF6)Z' The' preparation of this

compound and its Raman and .UV-visible spectra are discussed. Raman

spectroscopic and x-ray crystallographic studies show that the ions are

linear, and that the bond lengths increase in the order H9~Z+ < H9/+2+.

< H94Two new compounds containing infinite, linear, nOn-intersecting

chains of mercury atoms in two mutually perpendicular directions have

been prepared. The bonding in the metal atoms chains can be described

as metallic, with the charge delocalized over the mercury atom chains.

An experimental technique for measuring the electrical con­

ductivity of these extremely hygroscopic compounds is described, and

conductivity and optical ~tudies show that the compounds are anisotropic,

metallic conductors. They const~tute a new class of anisotropic materials.

iii

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ACKNOWLEDGEMENTS

I wish to thank Professor R.J. Gillespie, my research

superVisor, for his advice, enthusiasm and insight during the course

of thi s work.

The help and friendship of the members of the Chemistry

Department have made lIlY stay at McMaster rewarding and enjoyable.

I wish to thank Professor W.R. Datars of the Physics Department

for his assistance and also Mr. A. Van Schyndel for designing the

electronics, without which many of the results included in this thesis

c~uld not have been compl~ted.

I also thank Malerie I\el,<:lman for typi,ng this thesis and'"

Dave Hodgson for drawing the figures.-,

The 'financial assistance of the National Research Council,

who provided a Scholarship, and McMaster University and the Chemistry

Department, who provided an Assistantship, is gratefully acknowledged .•

iv

"" " CHAPTER I: INTRODUCTION,,'

1.1, Po1yatomic Cations of the Non-Metals

1.2 Po1yatomic Cation Fonnation by the Metal s

1.3 Pur~se Qf this Research

CHAPTER II: EXPERIMENT AL

2.1 Preparation and Purification of Ma~eria1s

2.2 Manipulation of Materials

2.2.1 Dry Box

2.2.2 Handling of Chemicals

2.2.3 Crystal Mounting

2.3 Experimental Techniques

-•..Y'

-,"

,

TABLE OF CONTENTS

2.3.1 Laser Raman Spectroscopy

'2.3.2 X-ray Crystallography

2.3. 3 , UV-Visib1e Spectroscopy

2.3.4 NMR Spectroscopy,

, 2.4 Conductivity Studies

2.4.1 E1ectronlcs

2.4.2 Sample Holder and Handling,

2.5 Preparative Reactions

2.5.1 The Reaction of Hg with AsF5

2.5.2 H9Z(AsF6)2.S02

2.5.3 Hg2(AsF6)Zv

PAGE,1

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CHAPTER II: EXPERIMEN~L (continued)

2.5.4 H93,AsF6)2

2.5.5 ~94(AsF6)2

2.5.6 H92.86Asf6

2.5.7 H9 with SbF5

2.5.8 H92(SbF6)2.S02

2.5.9 H92(SbF6)2

2.5.10 H93(Sb2Fl1)2

2.5.11 H92.91SbF6

2.5.12 H92(S03F)2

2.5.13 Elemental Analyses

CHAPTER III: THE MERCUROUS CATION

3.1 Introduction

3.2 Compounds of the H922+ Cation

3.2.1 Preparation and Identification

3.2.2 Raman Spectra

3.3 Mercury (I) Complexes

3.3.1 Oiscussion

3.3.2 Preliminary Crystal Structure

of H92(ASF6)2.S02

3.4 "The Stabil ity of the Mercurous Ion

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CHAPTER IV: THE H932+ CATION

4.1 Introduction

4.2 Compounds of the H932+ Cation

4.2.1 Preparation and Identification

4.2.2 UV-Visible Spectra·

4.2. 3 ~ Raman Spectra

4.3 The Structure of H93(AsF5)2

4.3.1 Solution and Refinement

4.3.2 Description of the Structure

CHAPTER V: THE H942+ CATION

5.1 Introduction

5.2 The H9/+ Cation

5.2.1 Preparation and Characterization

of H94(AsF5)2

5.2.2 Attem~ted Preparation of H94(Sb2Fl1)2

5.3 The Crystal Structure of H94(AsF5)2

5.3.1 Solution and Refinement

5.3.2 Description of the Structure

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CHAPTER VI: INFINITE CHAIN POLYMERCURY CATIONS 89

E.1 Introduction

6.2 The Structure of Hg 2.86AsF6

6.2.1 Solution and Refinement

6.2.2 Description of the Structure

6.3 Preparation and Structure of Hg2. 91 SbF6

89

gO

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CHAPTER VII: CONpUCTIVITY -AND OPTICAL STUDIES ON~ INFINITE CHAIN POLYMERCURY CATIONS 102

7.1 Introi:luction

7.2 Review of Anisotropic Materials

7.3 Conductivity Studies on Hg2.86AsF6

7>3.1 Crystal Growth'"

7.3.2 Results and Discussion

102

102

108

108

110

7.4 Conductivity and Optical Studies on

Hg2. 91 SbF6 115

7.4.1 Crystal Growth

7.4.2 Conductivity Experiments

7.4.3 Optical Studies

CHAPTER VIII: CONCLUSIONS

8.1 Introduction

8.2 Structures of Mercury Po1ycations

8.3 Infinite Chain Cations

8.4 Suggestions for Future WorkREFERENCES

viii

115

116

119

123

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127

128

129

•

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LIST OF TABLES

TABLE---r--

3.1 Raman Frequencies and Assigrments for

H92(AsF6)2·S02 and H92(AsF6)2

PAGE

30

3.2 'Raman Frequeneies for H92(OS02F)2 and

Related Molecules 363.3 Raman Frequencies and Assigrments for

3.4

39

44

3.5 Electronic Configurations a~d Ionization

Potentials for GpIIB Me~ls

ElectrOde Potentials for Mercury

3.6 Structural and Vibrational Data for

46

4.1

4.2

4.3

4.4

4.5

Mercurous Compounds

Raman Spectra of Hg32+ Compounds

Correlation Diagrams for'the Hg32+ IonJn

Hg3(AsF6)2 and Hg3(A1C1 4)2

Structural Parameters for Hg3(AsF6)2

Bond Distances and Bond Angles in Hg3(AsF6)2

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4.6 . Observed and Calculated Structure Factors

for H93{AsF6)2 •72

5.1 Crystal Data fo~ Hg4{AsP6)2 80

5.2 Structural Parameters for H94(AsF6) 2 82-

5.3 Bond Distances and Angle? in Hg4{AsF6)2 83

5.4 Observed and calculated Structure Factors

for Hg4{AsF6)2\

86

6.1 Crystal Data for Hg2.86AsF6 91

~

6.2 .Structural Parameters for Hg2.86AsF6 92

6.3 Selected Bond Distances and Angles for

Hg2.86AsF6 97

·6.4 Observed and Calculated Structure Factors

for Hg2.86As'F6 98.

6.5 Crystal Da~a for Hg 2. 91 SbF6 101;'

8.1 Polyatomic cations cif Mercury. 125-8.2 Bond Lengths and Hg-Hg Stretching Frequencies

for Mercury Polycations 126

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LIST OF FIGURES

FIGURE -PAGE

2.1 Block Diagram of Electronics for Conductivity

Experiments 12I

2.2 Sample Holder for Conductivity Experiments 14

3.1 Raman Spectra of H92(ASF6)2·S02' H92~AsF6)2

(S02 solution). and Hg2(AsF6.)2 29

. 3.2 Thermal Decompositi6n of H92(AsF6)2 33

,3.3 Raman Spect~ of H92(OS02F)2 35I

! •

I3.4 Raman Spectra of H92(Sb2Fll)2.S02'

H92(SbF6)2·S02 and H92(SbF6)2 38,:,'

4..1 Time Dependent UV-Visible Spectrum of'.H93(Sb2Fll)2i~ HS03F 55

~ .. 4-

4.2 Raman Spectra of Hg3(AsF6)2 and H93\Sb2Fll )2 57

4.3 Configuration of the Hg3(AsF6)2 Molecule 66

4.4 A Perspective Illustration of the Packing of

Ions in H93(AsF6)2 67

' .. 4.5 Projection of Asymmetric Unit of H93(AsF6)2 .;..:

Showing Hg .... F Contact 68

5.1 Temperature Dependent Raman Spectra of an

Equil ibrilllll Mixture of Hg32+ and H9/+ in S02

xi

76

FIGURE

5.2

5.3

6.1

6.2

Configuration of the Hg42+ Ion

A View of the Unit Cell Contents of

Hg4(ASF6)2 (viewed down the ~ axis)

hko and okt prece~on Photographs of

Hg2.86AsF6

A-Perspective Illustration of Hg2.86AsF6

PAGE

84

85

93

95

7.1 The CrYstal Structure of Kz[Pt(CN)4JBrO~30.3H20

Overlap of the d 2 Orbitals in theZ •

Platinum Chains

7;2 The ResistiVity of Hg2.86AsF6 as a Function

of Temperature

7.3 The Low Temperature Region of the Resistivity

of H92.8~sF6 and Bismuth as a Function of

Temperature

105

111

113

7.4 ,The Conductivity of H92.8~sF6 as a Function

of Temperature (normalized,to the room

temperature conductivity)

7.5

7.6

7.7

Temperature Oependent ~esistivity of Hg2. 91 SbF6

Relative Reflectivity of Hg2. 91 SbF6 as a Function

.of P61aroid Angle

Reflectivity of Hg2. 91 SbF6 as a Function ofo

Wavelength (4000-8000 A)

xii

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118

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CHAPTER I

INTRODUCTION

Mercury -was one of the firSrmeta1s__known to man, having been

discovered at least as early as the fifteenth or sixteenth century B.C.

Its liquid state and shiny metallic appearanc~ fascinated early chemists

and it played a central role in the Age of Alchemy, which reached its

zenith in seventeenth century Europe. Mercury, symbolizing the mineral

spirit of metals, and sulphur, symbolizing combustibility or the spirit.. '

of fjre, were considered to contain the essence of all metals. If the',

two "spirits" or "principles were.joined whilst in an impure state they

gave rise to base metals, such as tin and lead; when they were oT high

purity they gave silver and gold; but when each of the two principles was

of superfine purity they yielded the "Philosopher's Stone". One of the

favourite metals for multiplying an initial small quantity of ultrapurei

gold by means of the Philosopher's Stone was quicksilver, or mercury.

1.1 POLYATOMIC CATIONS OF THE NON-METALS

Polyatomic cation formation by the non-metals has been an

active research area in the last several years. Cation formation is

usually associated with the metals, but under suitable conditions the

elements of Groups VI and VII fonn cationic clusters. The I+ cation

has long been proposed as an intermediate in e1ectrophilic substitution

-1-