Table Of ContentStimuli-Responsive Self-Assembly and
Spatial Functionalization of
Organic Cages Based on
Tribenzotriquinacenes
Dissertation zur Erlangung des
naturwissenschaftlichen Doktorgrades
der Julius-Maximilians-Universität Würzburg
vorgelegt von
Ayan Dhara
aus Singarkone, Indien
Würzburg 2017
Eingereicht bei der Fakultät für Chemie und Pharmazie am:
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Gutachter der schriftlichen Arbeit:
1. Gutachter: Priv.-Doz. Dr. Florian Beuerle
2. Gutachter: Prof. Dr. Frank Würthner
Prüfer des öffentlichen Promotionskolloquiums:
1. Prüfer: Priv.-Doz. Dr. Florian Beuerle
2. Prüfer: Prof. Dr. Frank Würthner
3. Prüfer:
Prof. Dr. Udo Radius
Datum des öffentlichen Promotionskolloquiums:
_2_7_._10_._2_0_17____________
Doktorurkunde ausgehändigt am:
____________________
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Dedicated
To
My beloved
Parents
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List of Abbreviations
BARF Tetrakis(3,5-bis(trifluoromethyl)phenyl)borate
BET Brunauer-Emmett-Teller
CCDC Cambridge Crystallographic Data Center
COF Covalent Organic Framework
CTV Cyclotriveratrylene
D Diffusion Coefficient
DABCO 1,4-Diazabicyclo[2.2.2]octane
DCC Dynamic Covalent Chemistry
DCM Dichloromethane
DCTB trans-2-[3-(4-tert-Butylphenyl)-2-methyl-2-propenylidene]malononitrile
DIBAL-H Di-iso-butylaluminium hydride
DMSO Dimethylsulfoxide
DOSY Diffusion-Ordered Spectroscopy
EA Elemental Analysis
EM Effective Molarity
G Gibbs Free Energy
H Enthalpy
ITC Isothermal Titration Calorimetry
K Association Constant
a
k Boltzmann Constant
B
K Intrinsic Binding Constant
i
K Statistical Factor
σ
MALDI Matrix-Assisted Laser Desorption/Ionization
MOF Metal Organic Framework
MOMCl Methoxymethyl chloride
MS Mass Spectrometry
N Avogadro constant
A
NBS N-Bromosuccinimide
v
NMR Nuclear Magnetic Resonance
OAc Acetoxy
OMIM Organic Monomer with Intrinsic Microporosity
ORTEP Oak Ridge Thermal Ellipsoid Plot
OTf Trifluoromethanesulfonate
PIM Polymer with Intrinsic Microporosity
PM6 Parameterization Method 6
ppm Parts Per Million
p-TsOH para-Toluenesulfonic acid
Q Heat Change
R Gas Constant
r Radius
R Retention factor
f
rt Room Temperature
S Entropy
TBAF Tetra-n-butylammonium fluoride
TBTQ Tribenzotriquinacene
TES Triethylsilyl
TFA Trifluoroacetic acid
THC Tetrahedral Character
THF Tetrahydrofuran
TLC Thin Layer Chromatography
TMS Trimethylsilyl
TOF Time of flight
tpt 2,4,6-Tri(4-pyridyl)-1,3,5-triazine
η Viscosity
ρ Density
σ Symmetry Number
σ External Symmetry Number
ext
σ Internal Symmetry Number
int
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Table of Contents
Chapter 1 - Aim of the Thesis ........................................................... 1
Chapter 2 - Literature Survey .......................................................... 5
2.1 Boron-Nitrogen Dative Bonds in Supramolecular Assemblies .................................... 5
2.1.1 Geometry and Stability of Boron-Nitrogen Dative Bonds ..................................... 7
2.1.2 Boron-Nitrogen Dative Bonds as Secondary Interactions .................................... 10
2.1.3 Boron-Nitrogen Dative Bonds as Primary Interactions ........................................ 13
2.2 Tribenzotriquinacene ................................................................................................... 19
2.2.1 Structural Analysis ............................................................................................... 21
2.2.2 Synthesis of the TBTQ Scaffold ........................................................................... 21
2.2.3 Bridgehead-Functionalization .............................................................................. 23
2.2.4 Outer rim-Functionalization ................................................................................. 27
2.2.5 Ortho-Functionalization ....................................................................................... 30
2.2.6 Apical-Functionalization ...................................................................................... 31
2.3 Framework Materials .................................................................................................. 33
2.3.1 Covalent Organic Cage Compounds .................................................................... 34
2.3.2 Endohedral Functionalization of Covalent Organic Cage Compounds ............... 36
2.3.3 Exohedral Functionalization of Covalent Organic Cage Compounds.................. 38
Chapter 3 - Results and Discussion ................................................ 40
3.1 An Organic Cage Linked by Boron-Nitrogen Dative Bonds ...................................... 40
3.1.1 Design Principle ................................................................................................... 40
3.1.2 Model System ....................................................................................................... 42
3.1.3 Supramolecular Cage Based on Boron-Nitrogen Dative Bonds .......................... 46
3.1.4 Stimuli-Responsive Switching ............................................................................. 55
3.2 Apical Functionalization of Tribenzotriquinacene ...................................................... 59
3.2.1 Design Principles .................................................................................................. 60
3.2.2 Synthesis of Apically Functionalized Tribenzotriquinacene ................................ 62
3.2.3 Deprotection of Methoxy Groups ......................................................................... 67
3.2.4 Apically Functionalized Tribenzotriquinacenes ................................................... 68
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3.3 Functionalized Organic Cages .................................................................................... 72
3.3.1 Exohedral Cage Functionalization ....................................................................... 72
3.3.2 Synthesis of a 2-Substituted-meta-diboronic Acid .............................................. 76
3.3.3 Towards the Formation of Cages Possessing Both Interior and Exterior
Functionalities ............................................................................................................... 82
Chapter 4 - Summary ...................................................................... 86
Chapter 5 - Zusammenfassung ....................................................... 90
Chapter 6 - Experimental Section .................................................. 95
6.1 Materials and Methods ............................................................................................... 95
6.2 Synthesis and Characterization ................................................................................... 96
References ....................................................................................... 111
Appendix ......................................................................................... 120
Crystallographic Data ..................................................................................................... 120
Analytical Data ............................................................................................................... 123
Titration Data .................................................................................................................. 145
1H-NMR Spectroscopy ............................................................................................... 145
Isothermal Titration Calorimetry (ITC) ...................................................................... 147
Acknowledgements ........................................................................ 149
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Description:Section 3.2. The versatile modularity of this new approach is also showcased by introducing various functional groups at the apical positions of TBTQs. Based on the new apically functionalized TBTQ derivatives, the synthesis of exohedrally functionalized organic cages is documented in Section 3.3.
