ISOLATION OF SOFT DONOR COMPLEXES OF D

180 Pages·2015·4.83 MB·English

ISOLATION OF SOFT DONOR COMPLEXES OF D- AND F-BLOCK METALS
USING IONIC LIQUIDS

by
STEVEN PAUL KELLEY
ROBIN D. ROGERS, COMMITTEE CHAIR
DAVID E. NIKLES
THOMAS P. VAID
DAVID A. DIXON
ANJA-VERENA MUDRING

A DISSERTATION

Submitted in partial fulfillment of the requirements
for the degree of Doctor of Philosophy
in the Department of Chemistry
in the Graduate School of
The University of Alabama

TUSCALOOSA, ALABAMA

2015
Copyright Steven Paul Kelley 2015
ALL RIGHTS RESERVED
ABSTRACT

Ionic liquids (ILs) are alternatives to conventional molecular liquids or high-melting salts
which can be used to gain new insight into long-standing scientific questions. The ability to
access a compositionally variable, purely ionic liquid environment in an IL is particularly
significant in coordination chemistry, which often involves the manipulation of an ionic metal-
ligand bond. This study aims to demonstrate the potential utility of ILs in coordination chemistry
by using them to access unusual metal complexes with soft Lewis bases, especially those of f-
elements. Such complexes are particularly important use in studying the nature of f-element
chemical bonding and the interactions involved in their isolation, propagation through the
environment, or distribution in living organisms. A number of strategies using ILs and systems
derived from ILs are explored.
In reactions of dicyanamide-containing ILs with uranyl salts, the use of an IL as a source
of nitrogen-containing soft donor ligands led to the isolation of uranyl dicyanamide complexes
through substitution of oxygen-donor ligands by IL anions. By reacting actinide nitrate hydrates
with a nitrate-containing IL, anhydrous complexes were obtained which could be used as
precursors for the formation of nitrogen-donor adducts. The permanent elimination of oxygen-
containing anions from a metal salt was explored through reactions of an acidic azole with metal
acetate salts, although this approach was found to be limited by side reactions. The use of a
partially anionic sulfur ligand derived from an IL led to the formation of uranyl and neodymium
sulfur-donor complexes. The scope of nitrogen-containing ligands which could be incorporated
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into an IL was expanded by demonstrating the use of combinations of acidic and basic azoles as
liquids for nitrogen donor coordination chemistry.
These platforms have considerable room for expansion beyond the metal complexes
already isolated. Future studies will expand the range of soft donors incorporated in the IL
beyond nitrogen. Combinations of these strategies will also be explored with the aim of
producing entirely soft-donor ligated complexes from readily available starting materials.

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LIST OF ABBREVIATIONS AND SYMBOLS

(O) Two oxide ligands
2
(OH ) Aqua ligand
2
[(C CN)(C CN)Im]+ 1-(4-Cyanobutyl)-3-(2-cyanoethyl)imidazolium
4 2
[AlCl ]- Tetrachloroaluminate anion
4
[C C Im][OAc] 1,3-Diethylimidazolium acetate
2 2
[C mim]+ 1-Ethyl-3-methylimidazolium
2
[C mpyrr]+ N-Butyl-N-methylpyrrolidinium
4
[C mim]+ 1-Alkyl-3-methylimidazolium cation
n
[LnCl ]3- Hexachlorolanthanate
6
[N(CN) ]- Dicyanamide
2
[NH ]+ Ammonium cation
4
[NO ]- Nitrate
3
[NTf ]- Bis(trifluoromethane)sulfonylamide
2
[OAc]- Acetate
[Pu(NO ) ]2- Hexanitratoplutonate
3 6
[PuCl ]2- Hexachloroplutonate
6
[SO ]2- Sulfate anion
4
[UO ]2+ Uranyl cation
2
1,2,4-TAZ 1,2,4-Triazole
1-mim 1-Methylimidazole
2θ X-ray diffraction angle
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4,4’-bipy 4,4’-Bipyridyl
4,5-DCNIm 4,5-Dicyanoimidazole
5-AcAT 5-Acetamidyltetrazole
5-AT 5-Aminotetrazole
a Crystallographic a axis
 Reacts to form
Å Angstrom
Ag Silver
An Actinide
Ar Argon
ATR Attenuated total reflectance
b Crystallographic b axis
Ba(N(CN) ) Barium dicyanamide
2 2
Br Bromide
BTPhen 2,9-Bis(1,2,4-triazin-3-yl)-1,10-phenanthroline
C Carbon
c Crystallographic c axis
C=O C-O double bond
C≡N C-N triple bond
C C ImT 1,3-Diethylimidazole-2-thione
2 2
CCD Charge-coupled device
CCDC Cambridge Crystallographic Data Center
Ce Cerium
Cl Chlorine
Cl- Chloride
v
cm-1 Wavenumber
CMPO Octyl(phenyl)-N,N-diisobutylcarbomoylmethylphosphine oxide
CO Carbon monoxide
CrCl Chromium(III) chloride
3
CSD Cambridge Structural Database
Cu Copper
Cu(NO ) ·2.5H O Copper(II) nitrate hemipentahydrate
3 2 2
Cu-Kα Copper K-alpha
CuO Copper(II) oxide
DI Deionized
DSC Differential Scanning Calorimetry
DTPA Diethylenetriaminepentaacetic acid
eq. Equivalent
Eq. Equation
Eu Europium
F Fluorine
F2 Squared structure factor magnitude
FT Fourier transform
g Gram
h Hour
H O Water
2
H SO Sulfuric acid
2 4
H-Az Acidic azole
Hg Mercury
HgCl Mercury(II) chloride
2
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H-Im Imidazole
HOAc Acetic acid
I Iodine
I Calculated structure factor
calc
IL Ionic Liquid
I Observed structure factor
obs
IR Infrared
kJ Kilojoule
L Generic ligand
Ln Lanthanide
M Moles/liter
M(Az) Metal azolate
x
M(OAc) Metal acetate
x
mCi MilliCurie
Mg Milligram
min Minute
mL Milliliter
mm Millimeter
mmol Millimole
Mo-Kα Molybdenum K-alpha
mol Mole
MΩ·cm Megaohm centimeter
N Nitrogen
N Dinitrogen
2
Na Sodium
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NaN(CN) Sodium dicyanamide
2
Nd Neodymium
Nd(NO ) ·6H O Neodymium nitrate hexahydrate
3 3 2
NdCl ·6H O Neodymium chloride hexahydrate
3 2
N-donor Nitrogen donor
Ni Nickel
NMR Nuclear magnetic resonance
Np Neptunium
O Oxygen
oC Degrees Celsius
O-donor Oxygen donor
ORTEP Oak Ridge Thermal Ellipsoid Plot
Pb Lead
Pb(OAc) ·3H O Lead(II) acetate trihydrate
2 2
Pd Palladium
ppm Part per million
Pu Plutonium
PXRD Powder X-ray diffraction
R Residual for merging equivalent X-ray diffraction reflections
int
S Sulfur
SCXRD Single crystal X-ray diffraction
TALSPEAK Trivalent Actinide Lanthanide Separation by Phosphorous Reagent
Extraction of Aqueous Komplexes
Th Thorium
Th(NO ) ·4H O Thorium nitrate tetrahydrate
3 4 2
THF Tetrahydrofuran
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TRUEX TransUranic Extraction
U Uranium
U=O Uranyl U-O multiple bond
UO (NO )·6H O Uranyl nitrate hexahydrate
2 3 2
UO (OAc) ·2H O Uranyl acetate dihydrate
2 2 2
UO Cl ·3H O Uranyl chloride trihydrate
2 2 2
UO3 Uranium trioxide
UV/Vis Ultraviolet/Visible Light
wR2 Square of the weighted least squares residual
XAFS X-ray absorption fine structure
Z Formula units per unit cell
Zn Zinc
ZnO Zinc oxide
α Crystallographic alpha angle or alpha position on a molecule
β Crystallographic beta angle
γ Crystallographic gamma angle
η2 Eta-2 hapticity
λ Maximum absorption wavelength
max
μ Linear X-ray absorption coefficient
σ Standard uncertainty
-NH Amine functional group
2

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