FLUOROCATIONS OF KRYPTON, XENON AND BROMINE(VII)... ..
'. By. (
GARY JOrscHROBIlGEtl. !'l.S .. M.Sc.
A Thesis
..
I,,j
Submitted to the Faculty oJ'Graduate Studies
in Partial Fulfilment of the Requirements
for ,the Degree
Ooct~r Df ~Ailosophy
. ?'M'cMaster Universi ty
December 1973
..
GARY JOHN SCHROMLGEN· 1977"
..
---I
..
!OOCTO~ OF PHILOSOpHY (1973)(CheRn stry)
McMASTER UNIVERSnlYHamilton, Ontario
•TITLE: Fluorocations of Krypton, Xenon and Bromine(VII)
AUTHOR: Gary John! Schrobilgen, B.S. (Loras College),.... i •. M.Sc. (£\rock University) ..
SUPERVISOR: Professor R. J. Gillespie
NUMBER OF PAGES: xv, 219
SCOPE AND CONTENTS:
I
conditions and are probably the most potent oxidants presently known.I
Although the major.ity of the noble gas compounds studied in. + - +-this work can be approxlmatly formulated as NgFx MF6 or ~9fXOy MF6 ~
direct vibrational spectroscopic evidence for a weak covalent inter-•
action between the cation and a fluorine on the anion has been obtained+. -in the case of the krypton (II) salts and XeF3 SbF6 The X-ray
, . + -crystal structure of XeF3 SbF6 has also been determin~d and supports
tbe vi ew that these II fl uori ne bri dge i nteracti ons exhi bi t a substanti a1
degree of covalent ~haracter. consequ\n~~ the electron pair repulsion
.theory, which has proven highly successful jn predicting the geometries-,-
of isolated molecules has' also proven useful in assessing the preferred.I •
the fluorine-br-idged anion _and cation in sch id!9
relative geometr;e~ of+ -XeF3 SbF6 " and related noble gas compounds:
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iii
ACKNOWLEDGEMENTS) \
The a~thor wishes to thank his research director, Professor R.
J. Gillespie,. for his sincere interest in and encouragement of this
work.
Thanks are also due to the technical staff of McMaster University
for their maintenance of the nmr and laser Raman facilities and their
aid in constructi~g much of the apparatus. Much appreciation is also
extended to Mrs. Jan Gallo who typed this thesis.
The author also wishes to thank Drs. P. Boldrini and P. Ireland+ -who determined t~e si~gle crystal X-ray structure of 8-XeF3 SbF6 '
which is discussed in this thesis.
Financial assistance from. the National Research Council of
Canada" which provided sc~olarships for 1970-1973, is gratefully
acknowledged.
TABLE OF CONTENTS
Page·
1
1
2
2
2
4
5
5
7
8
8
9
.,'-12 -12
"12
(i) General
(i i) "Xenon Fl uori des
(i i 1) Xenon Oxyfluorides
(iv) Xenon Oxides
(v) Krypton Fluorides
(vi) Radon Fluorides
(i) ·The Valence Shell Electron Pair Repulsion(VSEPR) Theo'ry
,(ii) Flu~rine Bridge Interactions
(E) H;gh-R~solution 19r 'NMR Studies of Noble-Gas.~
Compounds 14
(C) Fluoro- and Oxyfluor~cations of the Noble Gases
(i) General
(ii) Applications of Noble-Gas Cation Chemistry
(D) Structural Aspects of the Noble-Gas Compoundsand Their Cations
Introducti onII
(A) Hi'sto~ical
(B) Noble-Gas Fluorides, Oxyfluorides and Oxides
CHAPTER I:
'J, (F) Pur.pose of the Present Work 17
CHAPTER II~ Experimental
(A) V~cuum Techriiques
(i)
(11 )
General Comments,
VaCUlI1l Lines
19'
19
19
19
.ff
.v
(iii) Valves
(iv) Preparative Apparatus
(B) Preparation and Purification of StartingMaterials
( 1) Fl uori ne
(ii) Ine~t Atmospheres
(iii) Xenon Difluoride
(iv) - Xenon Tetrafluoride
(v) Xenon Hexa.f'l uoride
(vi) Xenon OXYfluorides
(vii) . Krypton Difluoride
(viii) Fluoride Acceptors
(ix) Solvents'
'(x) Othe'r Ma teri a1s \
Preparation of Salts of the NOble-~Cations
and Related Compounds
General Comments
+ -and XeF3 SbF6+and xeOF3 SbF6
50
48
43
31
31
31
32
33
34
35
J7
39
39
40
..47
47
44
45
45
42
42
. Page
24
27
Previously Reported Compoun~s of Xenon
(FXe)2S03F+ASF6-
F5XeS03F+ -XeF3 Sb2F11+ -XeOF3 Sb2F
11+ -Xe02F Sb2F11
+ - + - +-KrF Sb2F11 ' KrF SbF6 ' Kr2F3 SbF6 and+ - 'Kr2F3' SbF6 -xKrF2+ - + - +-a-KrF A~f~ , ,8:KrF AsF6 ' Kr2F3 AsFS
and Kr2f 3 AsF6
(ix)
(1)
(i i)
(iii)
(i v)
(v)
(vi)
(vi i)
(viii)
(e)
vi
(D) Instrumentation
(x)
(xi)
(xi i)
(xi i i)
(xi v)
+ KrF PtF6+ - + -BrF6 AsF6 and BrF6 Sb2F11
+ -Attempted Synthesis of BrF6 AsF6 byOther Means
Displacement Reaction between NOF and+ -BrF6 AsF6'+ -BrF4 Sb2F11
Page
52
53
53
54
55
55
(i) Nuclear Magnetic Resonance Spectroscopy 55
(ii) Laser Raman Spectroscopy 56
(iii) Sample Preparation 57
CHAPTER III: 19 F Nuclear Magnetic Resonance Studies of Some Xenon(II)Compounds
" Introduction
"Resu1ts and Di scuss ion
(A) Xenon(II} Fluorosulfates
(B) The XeF+ Cation
(C~ The xe2F3+ Cation
(0) Empirical Correlations
60 ,60
60
60
64-"\"
67 ,'1\
71
.CHAPTER IV: A 19F NMR and Raman Study of the {FXe)2S03F+ Cation;
The Preparation and Characterization of(FXe)2S03F+ASF6- 74
.~
Introduction 74
Results and Discussion
(A) 19F N~m Spectroscopy\
(8) Preparation of (FXe)Zso3F+ASF6-'
vii
75
75
78
(c)
( D)
+Decomposition of (F~~)2S03F
Raman Spectroscopy
Page
79
81
CHAPTER V: ' A 19F Nuclear Magnetic.Cation and F
SXeS0
3F
Introduction
,---- +Resonance Study of the XeFS '
88
88
"
97
Results and Discussion 89• +CA) NMR Spectra of Solutions of XeF6 and XeFS
Salts in HF, HS03F and BrFS 89
(B) Preparation of F~XeS03F and the Solution NMRSpectra of F5XeS03.F and XeF6 93..
(C) . Solvent Effects 96
(D) Temperature Dependence of the Equatorial129Xe_19 F Coupling Constant
(E) Double Resonance Experiments 99
CHAPTER VI: The xeF3+, XeOF3
+ and xe02
F+ Cations~ Their Preparationand Characterization by 19F NMR Spectrosco~y 99
Introduction
Results and Discussion.(A)
(B)
(C)
, (D)
Preparation and Properties
19F NMR Spectroscopy
+(1) XflF3+(11 ) XeOF3+
(i i i) Xe02
F
Empirical Correlation of the 129Xe_19F Coupling
Constant and the 19F Chemical Shift
Correlation of the NMR Parameters with theOxidation St.ate of Xenon'
101
102
102
105
105
107
110
112
115
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Results' and Oiscussion
CHAPTER VII: The Crystal Structure and Raman Spectrum of+ -8-XeF
3SbF
6
Introduction
(A)
( B)
ee)
•Crystal Data
DescriptioQ and Discussion of the Structure+ -Raman Spectrum of B-XeF
3SbF
S
116
116 ~
117
117
117
129
Results and Discussion
Syntheses, Properti~s and Reactions, I
19F NMR Spectroscopy
Th~ KrF+ and Kr 2F3+ Cations: The+ - , + + -
KrF MF6 ' KrF Sb2F11 ' Kr 2F3 MFSand Their Characterization by 19FSpectroscopy ~
lntroduc ti on
CHAPTER VI I I:
(A)
(B)
(C) Raman
(i) .
(i i)
(; i i)
(iv)
(v)
Prepara ti on of+ -and Kr 2F3 MF6 -xKrF2
NNR and Raman
...Spectrosc'opy
+ - (' + -KrF MF6 and KrF Sb2F11Valence Stretching Force Constants
+ +of ~rF and XeF+ -' +-Kr
2F3
SbF6
and Kr2
F3
AsF6
+ - + -Kr2
F3
SbF6
-XKrF2
and Kr 2F3 ASF6 -xKrF2The Question of the Purity of the
+ -Kr2F3 MF6 'Salts
137
138
138
138
143
149 ~149
165
169
177
181
CHAPTER IX: The Hexafluorobromine(VII) Cation, BrF6+: The Preparation of BrF6+ASF6- and BrF6+Sb2F
11- and Their
Character-ization by 19F NMR and Raman Spectroscopy
ix
183
CHAPTER X:
REFERENCES
Introduction
. Results and Disc;:ussion
. ~A) 19F NMR Spectroscopy
(B) Raman Spectroscopy.(C) Reaction of BrF6+ with Oxygen and Xenon
(D) Attempted Synthesis of BrF7Summary
Concl usions
(A) Introduction
(B) 19F NMR Spectroscopic Studies of Noble-GasSpecies
(e) Fluorine-Bridge Interactions
(0) '~uture Directions for Research
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Page
183
183
183
190
197
198
198
200
ZOO
200
'202
208
211
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LIST OF TABLES
Table
1.1 )The Noble-Gas Cations and Their First Discovery
7~3 Equations for Least Squares PlanesI
- ' ....-7.4 Raman ppectra and Assignmen~ 'of a-XeF3 SbF6 and~ + -a-XeF3 SbF
Q
3.1
3.2
3.3
3.4
4.1
4.2
4.3
5.1
5.2
6.1
7.1
7.2
~ .The Known Molecular Geometries of Noble-Gas Compounds
Noble-Gas Compounds Studied by 19F NMR SpectroscopyPri or to thi s \~ork-
19F NMR Parameters for XeF2 , FXeS03
F and Xe(S03F)2
19F NMR Parameters for the XeF+ and Xe2
F3+ Cations
Variation ~f 19F Chemical Shift and 129Xe _19 F CouplingConstant for the XeF+ Ion with Solvent Composition
Correlations among the 19F NMR Parameters, Xe-F BondDistances and Xe-F Stretching Frequencies
19F NMR'Parameters for the (FXe)2S03F+ Cation andRelated Systems
The Raman Spectra 0: FXeS03F, Xe(S03F)2 and(FXe)2S03F+ASF6-
Vibrational Frequencies for Bridging ~03F Groups in I02S03F,'. +
(CH3)2Sn (S03F)2' 'S~F4S03F and ,(FXe)2S03F
NMR Parameters for the xeFs+ Cation in Various Solvents
Variation of the Fluorine-an-Xenon Line Width for Solutionsof XeF6 and FSXeS03 F in C1FS and BrFS19 . + + +F NMR Parameters for XeF3 ' XeOF3 and Xe02F in SbF5Solution .
0+_lntera:tomic Ois:tances (A) and Angles (deg.) for B-XeF3 SbF6Comparison of the Structures of XeF3+, BrF 3 and C1F3
Page
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13
16
62
66
68
72
77
83
85
91
95
109
120
122
123
130
xi·
Table
7.5
8.1
Correlation Diagram for the xeF3+ Modes19 + +F NMR Parameters for Kr2F3 ' KrF andXenon Analogs
+ -of B-XeF3 SbF6KrF2 and Thei r
Page'
133
144
/
8.2
8.3
8.4
8.5
8.6
8.7
8.8
9.1
9.2
9.3
10.1
+ -Raman Spectra and Assignments for 'Some KrF MF6 Saltsand Their Xenon Analogs
I'
Raman Spectr.a of KrF+~b2F11- and xeF+Sb2F1i-Description of the Vibrational Modes and Correlations for
-Oh and C4V Molecules
Vibrational Frequencies for Some MFSX and MF6 Species
Correlation of the Valence Stretchin9 Force Constants andBond Lengths of NgF2, N9F+ and Some Monohalofluorides
, + .Raman Spectra of Some Kr2F3 Salts and ':heir _Xeno~ Analogs
Correlation Diagram f~r 0 h,' C· and C Symmetries¢o (bV S
19 + . +F NMR Parameters for the BrF6 and BrF4 Ions. + -' + - +Raman Spectra of BrF6 Sb2F11 ' BrF6 AsF6 and BrF4 Sb2F11
and Their Assignments+Vibrational Frequencies and Assignments of the' BrFS Cation
and Some Related Species
Observed Vibrational.!requencies and Structural Parametersof Some Xenon( II) Compounds
xii
150
151
160
161
'-166
170
175
185
191
195
205
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LIST OF FIGURES
Figure
2.1 General purpose vacuum li~e a~d HF distillation appqratus 20
2.2 General purpose fluorine line 21I"
2.3 Diagram of the glass line used to prepare krypton difluoride 22
2.4 V~cuum diaphragm valve for the manipulation of corr6sivefluorides 26
2.5 Fluroplastic preparative apparatus 28."
2.6
3.1
3.2
3.3
4.1 -
4.2I
5.1
5.2
5.3
Apparatus for the storage and handling of KrF2The 19F nmr spectrum (58.3 MHz) of a solution ofFXeS0
3F (~ 0.5 m) in HS0
3F solvent
The 19F nmr spectrum (56.4 MHz, -62°) of the Xe 2F3+
cation (0.67 m Xe2F3+AsF6- in BrFS solvent)
c~rrelat;on of ~he 19F chemical Shi;t (019 ) and th~129X~_19F coupling con\tant (J129 19) f~r some ~enon(II)c~mpounds Xe- F
The 19F nmr spectrum (56.4,MHz) of a solution of(FXe)2s03F+ASF6- (0.92 m) prepared by.dissolvingXe2F3+AsF6- in HS03F at -78 0
The Raman spectrum (-90°) of soli~ (FXe)2S03F*ASF6contained ,; n a glass sa~ple tube
The 19F nmr spectrum (56.4 MHz, 26°) of the X~F5+ cation+ _ d
(4.87 m XeFS SoF6 in HF solution)
Variation of the equatorial fluorine-xenon-129 couplingconstant of the xeFs+ cation with 1fT (0.481 m XeF6 and1.40 m SbF
Sin' HS03F solution)
The 19F nmr·spectrum (56.4 MHz, -81°) of the equatorialfluorines of the xe'F5+ cation (tV I,m F5X~S03f in HS03Fsolution); unperturbed arid with simul~aneous irradiat1bnof the 129 Xe transitions
xiii
30
63
70
73
76
82
90
98
lOP
•