Functional Cage-Amine Complexes

254 Pages·2008·3.61 MB·English

Functional Cage-Amine Complexes:
Polymerisable Metallomonomers and Multi-Cage
Complexes

By
Nigel Andrew Lengkeek B. Sc. (Hons) B.E. (Hons)

This thesis is presented for the degree of Doctor of Philosophy of The University of
Western Australia, Discipline of Chemistry, School of Biomedical, Biomolecular and
Chemical Sciences, December 2007.

………..……………..
Nigel A. Lengkeek
DECLARATION FOR THESES CONTAINING PUBLISHED WORK

AND/OR WORK PREPARED FOR PUBLICATION

1
This thesis does not contain work that I have published, nor work under consideration for publication. The
thesis is completely the result of my own work, and was substantially conducted during the period of
candidature, unless otherwise stated in the thesis.

Signature……………………………….

22
This thesis contains sole-authored published work and/or work prepared for publication. The bibliographic
details of the work and where it appears in the thesis is outlined below.

Signature………………………………

3
This thesis contains published work and/or work prepared for publication, some of which has been co-
authored. The bibliographic details of the works and where they appear in the thesis are set out below.
(The candidate must attach to this declaration a statement detailing the percentage contribution of each
author to the work. This must been signed by all authors. Where this is not possible, the statement detailing
the percentage contribution of authors should be signed by the candidate’s Coordinating Supervisor).

The Following chapters contain work that is being prepared for publication:

Chapter 2 & 3: J. M. Harrowfield, G. A. Koutsantonis, N. A. Lengkeek, B. W. Skelton & A. H. White, ‘Cinnamyl
functionalised Cage Amine Complexes: Synthesis, Structure and Copolymerisation’, Manuscript in
Preparation

J. M. Harrowfield, G. A. Koutsantonis, N. A. Lengkeek, B. W. Skelton & A. H. White, ‘Styryl
functionalised Cage Amine Complexes: Synthesis, Structure and Copolymerisation’, Manuscript in
Preparation

J. M. Harrowfield, G. A. Koutsantonis, N. A. Lengkeek, B. W. Skelton & A. H. White, ‘Reactivity of
Cinnamyl-Cage-Amine Complexes with Reducing Agents: Cleavage and Reduction to
Phenylpropyl-Cage-Amine Derivatives’, Manuscript in Preparation

Chapter 4: J. M. Harrowfield, G. A. Koutsantonis, N. A. Lengkeek, B. W. Skelton & A. H. White, ‘Thiophene
Derivatives of Cage Amines: Synthesis, Structure and Electrochemistry’, Manuscript in preparation

J. M. Harrowfield, G. A. Koutsantonis, N. A. Lengkeek, ‘Synthesis and Electropolymerisation of N-
(4’-carboxybenzene)-2,5-di(2’’-dithienyl)pyrrole’, Manuscript in preparation

Chapter 5: J. M. Harrowfield, G. A. Koutsantonis, N. A. Lengkeek, B. W. Skelton & A. H. White, ‘Electronic
communication is a simple p-xylyl-bis-cage-amine complex’, Manuscript in Preparation

Signature………………………………
Statement of Candidate Contribution

Chapter 2 & 3:
J. M. Harrowfield, G. A. Koutsantonis, N. A. Lengkeek, B. W. Skelton & A. H. White,
‘Cinnamyl functionalised Cage Amine Complexes: Synthesis, Structure and
Copolymerisation’, Manuscript in Preparation
JMH (5 %), GAK (10 %), NAL (75 %), BWS (5 %), AHW (5 %)

J. M. Harrowfield, G. A. Koutsantonis, N. A. Lengkeek, B. W. Skelton & A. H. White,
‘Styryl functionalised Cage Amine Complexes: Synthesis, Structure and
Copolymerisation’, Manuscript in Preparation
JMH (5 %), GAK (10 %), NAL (75 %), BWS (5 %), AHW (5 %)

J. M. Harrowfield, G. A. Koutsantonis, N. A. Lengkeek, B. W. Skelton & A. H. White,
‘Reactivity of Cinnamyl-Cage-Amine Complexes with Reducing Agents: Cleavage and
Reduction to Phenylpropyl-Cage-Amine Derivatives’, Manuscript in Preparation
JMH (5 %), GAK (10 %), NAL (75 %), BWS (5 %), AHW (5 %)

Chapter 4:
J. M. Harrowfield, G. A. Koutsantonis, N. A. Lengkeek, B. W. Skelton & A. H. White,
‘Thiophene Derivatives of Cage Amines: Synthesis, Structure and Electrochemistry’,
Manuscript in preparation
JMH (5 %), GAK (10 %), NAL (70 %), BWS (10 %), AHW (5 %)

J. M. Harrowfield, G. A. Koutsantonis, N. A. Lengkeek, ‘Synthesis and
Electropolymerisation of N-(4’-carboxybenzene)-2,5-di(2’’-dithienyl)pyrrole’,
Manuscript in preparation
JMH (5 %), GAK (10 %), NAL (85 %)

Chapter 5:
J. M. Harrowfield, G. A. Koutsantonis, N. A. Lengkeek, B. W. Skelton & A. H. White,
‘Electronic communication is a simple p-xylyl-bis-cage-amine complex’, Manuscript in
Preparation
JMH (5 %), GAK (10 %), NAL (70 %), BWS (10 %), AHW (5 %)

We hereby declare that the individual authors, or corresponding authors, have granted
permission to the candidate (Nigel A. Lengkeek) to use the results presented in the
manuscripts in this thesis.

……….……….……….………. ……….……….……….……….
Nigel Lengkeek Dr. George A. Kousantonis
(PhD Candidate) (Coordinating Supervisor)
"Because you think yourself but one among the many threads which make up the
texture of the doublet. You should aim at being like men in general, just as your thread
has no ambition either to be anything distinguished compared with the other threads.
But I desire to be the purple, that small and shining part which makes the rest seem fair
and beautiful. Why then do you bid me become even as the multitude? Then were I no
longer the purple."
EPICTETUS
Acknowledgements
First and foremost I would like to thank Dr. George Koutsantonis and A/Prof. Jack
Harrowfield for doing the onerous job of being PhD supervisors so well, their
discussions about chemistry and pretty much everything else and for their belief in the
importance of a strong morning coffee to kick start the day and 4pm beers on Friday to
cap off a week of work.

The journey that is any PhD would not be the same without the people you share the lab
(and solvent roster) with, so I would like to thank the PhD students I have worked with
in the lab over the many years, Paul Donnelly, Chris Griffith, Gareth Nealon, Brad
Berven, Nicole Hondow, Phil Schauer and Becky Fuller for making the lab an enjoyable
place to work and helping keep me sane. Also to the many honours students over the
years Dave Dennis, Gareth Jenkins, Alison Steer, Barbara Szepaniack and Tim Allen,
cheers.

There are of course many people outside the research group that I must thank for their
help along the way, in particular, Ylenia Casadio for enduring the trials and tribulations
of setting up GPC equipment from scratch with me, Nathan Webster for his help with
XRD, weekly laksa lunches and for joining the engineer-turned-chemist pile, and Pete
Melloncelli for being the go-to-guy for all my ‘organic’ chemistry woes and sharing my
taste in German beer. I must also thank all the non-chemistry students in the MCS
building I have got to know, you have given me the opportunity to talk about something
besides chemistry at tea breaks, the chance to cross the chemistry/biochemistry
‘invisible’ line and meet some wonderful people, thanks heaps!, particularly to the 4 pm
trash talk crew.

My visit to Université Louis Pasteur was one of the most enjoyable parts of my PhD, so
I am indebted to the hospitality of Prof. Jean-Pierre Sauvage for allowing me to work in
his research group. I would like to thank all the people I worked with, became friends
with and helped me deal with the French bureaucracy, particularly Dr. Jean-Paul Collin,
Julien Frey, Boniet Champin, Yves Rogister, Sana Amir, and all the other chemistry
crew in ICOM and Institut Le Bel for showing me a great time and attempting to
convince me and everyone else that “Aussies love Fosters mate!”, even if it was brewed
in France. I must also acknowledge the financial assistance of a UWA Convocation
Alexander Cohen Postgraduate Travel Award and the UWA Postgraduate Travel Award
for making the trip possible.

Without the superb efforts and hard work of Dr. Brian Skelton and Prof. Allan White
the X-ray crystallography presented in this work and resultant ‘pretty pictures’ may
never have seen the light of day, thus to both of them I am deeply grateful.

I am extremely grateful for all the help I have received from technical staff in the
School. Dr. Lindsay Byrne for his seemingly limitless patience and knowledge of NMR,
Dr. Tony Reeder for acquisition of Mass Spectra, Oscar Del Borello for assistance with
AAS, the ‘workshop boys’, Nigel Hamilton, Andrew Sawyer and Norm Poulter for their
help with troublesome equipment and assistance in construction of a
spectroelectrochemical cell, and finally Greg Cole and Sarah Davis for their glass
blowing expertise.

Finally I would like to thanks my friends and family for their support, particularly over
the last few months while writing this thesis, I am sure they will be as glad as I am to
see it finished.
Abstract
Abstract
Chapter 1 provides an introduction to the ‘sarcophagine’ class of ligands and the field
of metallopolymers. The synthesis, stereochemistry, physical properties and
functionalisation of ‘sarcophagines’ and their metal complexes are discussed. A brief
overview of the burgeoning field of metallopolymers is given with specific mention of
the synthetic routes to pendant metallopolymers, and how these could be employed to
prepared cage amine containing metallopolymers.

Chapter 2 deals with the synthesis, characterisation and reactivity of cinnamylamino
and styrylamido derivatives of the cage amines [Co((NH ) sar)]3+,
2 2
[Co((CH )(NH )sar)]3+ and [Cu((NH ) sar)]2+. The cinnamylamino derivatives were
3 2 2 2
prepared using reductive alkylation of the aforementioned amines with cinnamaldehyde.
Procedures were developed to isolate the complexes without causing unwanted
additions to the double bond. The cinnamylamino derivatives displayed unexpected
reactivity towards a range of reducing agents, resulting in unexpected reduction of the
double bond and cleavage of the cinnamyl group, but ultimately in the preparation of
phenylpropylamino derivatives of [Co((NH ) sar)]3+ and [Co((CH )(NH )sar)]3+.
2 2 3 2
Attempts to rationalise the reactivity of the double bond have been explored based upon
the physical properties and reactivity of the double bond. The styrylamido derivatives
were prepared by treatment of the cage amines with 4-vinylbenzoyl chloride, and the
complexes isolated in a similar manner to those of the cinnamylamino derivatives to
ensure the amide linkage remained intact. Most of the complexes have been structurally
characterised. Electrochemical examinations of the complexes served not only as a
method of characterisation for the complexes, but a possible route to the
electropolymerisation of the complexes, unfortunately electropolymerisation was not
observed even under a range of conditions.

Chapter 3 examines the chemical homopolymerisation and copolymerisation (with
styrene) of the cinnamylamino and styrylamide cage amine complexes prepared in
chapter 2. Homopolymerisation was not apparent under a range of conditions, but
copolymers of both classes of monomers were prepared. The controlled radical
polymerisation techniques, RAFT and ATRP, were employed in an attempt to prepare
block copolymers of styrene with the cinnamylamino and styrylamide complexes. The
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Abstract
reactivity of cage amines towards two functionalised polymers, Merrifield resin and
poly(vinylbenzoic acid) was explored. Reaction of (NH ) sar with the former gave
2 2
polymers that were capable of coordinating a range of metals.

Chapter 4 deals with the synthesis, characterisation and attempted polymerisation of
cage amines containing thienyl substituents. Both the 2-thienyl and 3-thienyl derivatives
of [Co((NH ) sar)]3+ and [Co((CH )(NH )sar)]3+ have been prepared using reductive
2 2 3 2
alkylation with the respective carboxaldehydes of thiophene. One of the optically pure
isomers has been prepared. The complexes have been fully characterised including
structural characterisation. Polymerisation of the thiophene-cage amine complexes was
investigated under a range of chemical and electrochemical conditions, though
polymerisation was never observed. Cleavage of the thienyl groups was observed when
ceric ammonium nitrate in nitric acid was used as the oxidant. The attachment of
oligothiophenes and mixed pyrrole-thiophene oligomers to cage amines were
investigated using reductive alkylation and various pyrrole ring-forming reactions about
the apical amino groups, though none of the desired complexes were isolated, reasons
for the lack of reactivity were discussed. An efficient synthesis of N-(4-benzoic acid)-
2,5-di(2-thienyl)pyrrole was developed and was shown to the electropolymerisable,
albeit the polymer films were non-conducting. Attempts to couple N-(4-benzoic acid)-
2,5-di(2-thienyl)pyrrole with a cage amine via its acid chloride were complicated by
decomposition reactions, the nature of one of these products is discussed.

Chapter 5 presents investigations into the preparation of simple complexes containing
multiple cage amines using alkylation and acylation procedures with aromatic
substrates. The complexes were found to exhibit some interesting electrochemical and
chemical properties, demonstrating that even simple multiple cage amine species can
display complicated and interesting behaviour.

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Abbreviations
Abbreviations
GENERAL
°C Degrees Celsius
AAS Atomic Absorption Spectroscopy
ABCPA 4,4’-Azobis(4-cyanopentanoic acid)
AIBN 4,4’-Azobis(isobutyronitrile)
ATRP Atom Transfer Radical Polymerisation
BINAP 2,2'-Bis(diphenylphosphino)-1,1'-binaphthyl
CAN Ceric Ammonium Nitrate
conc concentrated
CRP Controlled Radical Polymerisation
CPDTB 4-Cyanopentanoic acid dithiobenzoate
dba Dibenzylideneacetone
DBU 1,8-Diazabycyclo[5.4.0]undec-7-ene
DeI H O Deionised water
2
DMF Dimethylformamide
DMSO Dimethyl Sulphoxide
dppf 1,1'-Bis(diphenylphosphino)ferrocene
EtOAc Ethyl Acetate, CH CH OC(O)CH
3 2 3
FRP Free Radical Polymerisation
IR Infra-red (Spectroscopy)
meq/g milli equivalents per gram
mmHg Millimetres of Mercury
NBS N-Bromosuccinimide
(NH ) sar 1,8-Diaminosarcophagine
2 2
(NH )(CH )sar 1-Amino-8-methylsarcophagine
2 3
NMR Nuclear Magnetic Resonance (Spectroscopy)
PEDTB 1-Phenethyldithiobenzoate
Ph Phenyl (C H -)
6 5
PTSA Para-toluene sulphonic acid (4-methylbenzene sulphonic acid)
RAFT Reversible Addition-Fragmentation chain Transfer (polymerisation)
rcd recovered
R.T. Room Temperature
sar Sarcophagine, 3,6,10,13,16,19-hexaazabicyclo[6.6.6]eicosane
sen 1,1,1-Tris(1’-amino-3’-azabutyl)ethane
SNS Dithienylpyrrole (2,5-di(2’-thienyl)pyrrole)
tart Tartrate, C H O 2-
4 4 6
THF Tetrahydrofuran
Tol Toluene
TRIS Tris(hydroxymethyl)aminomethane (2-Amino-2-
(hydroxymethyl)propane-1,3-diol)
XRD X-Ray Diffraction (Powder)

FOR NUCLEAR MAGNETIC RESONANCE
cm complex multiplet
COSY Correlation Spectroscopy
d doublet
dd doublet of doublets
m multiplet
t triplet
HMBC Heteronuclear Multiple Bond Coupling
HSQC Heteronuclear Single Quantum Coherence
NOE Nuclear Overhausser Effect

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Abbreviations
FOR ION EXCHANGE CHROMOATOGRAPHY
CM Carboxymethyl (Sephadex)
SE Sulphonylethyl (Sephadex)
SP Sulphonylpropyl (Sephadex)

FOR ELECTROCHEMISTRY
ΔE Peak separation in Cyclic Voltammetry ( = E – E )
Red ox
CV Cyclic Voltammetry (Cyclic Voltammogram)
DPV Differential Pulse Voltammetry
E Electrode Potential
E Electrode Potential of an Oxidation Process
Ox
E Electrode Potential of a Reduction Process
Red
I/I Ratio of anodic and cathodic peak currents
a c
SCE Standard Calomel Electrode
TBAP Tetrabutylammonium Perchlorate

FOR MASS SPECTROMETERY
FAB Fast Atom Bombardment
ESI-MS Electrospray Ionisation Mass Spectrometry
EI Electron Ionisation
HR High Resolution
NOBA 4-Nitrobenzyl Alcohol

FOR GEL PERMEATION / SIZE EXCLUSION CHROMATOGRAPHY
DAD Diode Array Detector (part of GPC equipment)
GPC Gel Permeation Chromatography
M Number Average Molecular Weight
n
M Weight Average Molecular Weight
w
MW Molecular weight
PDI Polydispersity (= M /M )
w n
RID Refractive Index Detector (part of GPC equipment)
SEC Size Exclusion Chromatography

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