Photoinduced charge transfer processes in triarylamine based redox cascades [Elektronische Ressource] / vorgelegt von Marco Holzapfel

Marco Holzapfel

Informations

• Publié par: julius-maximilians-universitat_wurzburg
• Publié le: 01 janvier 2007
• Nombre de lectures: 29
• Langue: Deutsch
• Poids de l'ouvrage: 1 Mo

Extrait

Photoinduced Charge Transfer
Processes in Triarylamine Based Redox
Cascades













Dissertation zur Erlangung des
naturwissenschaftlichen Doktorgrades
der Julius-Maximilians-Universität Würzburg







vorgelegt von
Marco Holzapfel
aus Aschaffenburg



Würzburg 2007







Eingereicht am: 5. Oktober 2007
bei der Fakultät für Chemie und Pharmazie



1. Gutachter: Prof. Dr. Christoph Lambert
2. Gutachter: Prof. Dr. Ingo Fischer
der Dissertation


1. Prüfer: Prof. Dr. Christoph Lambert
2. Prüfer: Prof. Dr. Ingo Fischer
3. Prüfer: Prof. Dr. Frank Würthner
des Öffentlichen Promotionskolloquiums


Tag des Öffentlichen Promotionskolloquiums: 3. Dezember 2007





Die vorliegende Arbeit wurde in der Zeit von September 2003 bis September 2007
am Institut für Organische Chemie der Universität Würzburg angefertigt.






















Mein besonderer Dank gilt

Herrn Prof. Dr. Christoph Lambert

für die Vergabe des vielseitigen Themas, die intensive Betreuung und Förderung und
das mit vielen Anregungen und Diskussionen verbundene Interesse an dieser Arbeit.










Falls Gott die Welt geschaffen hat, war seine Hauptsorge sicher nicht,
sie so zu machen, dass wir sie verstehen können.

Albert Einstein
(1879 – 1955)











meinen Eltern



Contents

1 Introduction ..........................................................................1
1.1 Fundamental Importance of Electron Transfer Processes ....1
1.2 Theory ........................................................................................2
1.2.1 Diabatic and Adiabatic Electron Transfer .............................. 3
1.2.2 Marcus Theory ..........................................................................5
1.2.3 Extension of Marcus Theory ................................................... 9
1.2.4 Electron Transfer Mechanisms ............................................. 14
1.2.4.1 Superexchange Mechanism ..............................................14
1.2.4.2 Hopping Mechanism ..........................................................15
1.3 State of the Art .........................................................................16
1.3.1 Application of Suitable Redox Centres ................................ 16
1.3.2 Possible Approaches to Realise a Long-lived CS State .... 22
1.4 Project Aim ..............................................................................27
1.4.1 Design of the Cascades ......................................................... 27
1.4.2 Characterisation of CS States ............................................... 29

2 Transient Absorption Spectroscopy of Fluorescent
Compounds in the ns Time Domain ................................30
2.1 Introduction .............................................................................30
2.2 Results and Discussion ..........................................................31
2.3 Conclusion ...............................................................................35






3 Photoinduced Charge Separation and Recombination
in Acridine-Triarylamine Based Redox Cascades ..........36
3.1 Introduction .............................................................................36
3.2 Results and Discussion ..........................................................39
3.2.1 Synthesis ................................................................................39
3.2.2 Redox Properties .................................................................... 44
3.2.3 Stationary Spectroscopy .......................................................46
3.2.3.1 Steady State Absorption Spectroscopy ...........................46
3.2.3.2 Steady State Emission Spectroscopy ..............................48
3.2.4 Time Resolved Spectroscopy ...............................................51
3.2.4.1 Time Resolved Fluorescence Spectroscopy ...................51
3.2.4.2 Transient Absorption Spectroscopy ................................59
3.3 Conclusion ...............................................................................71

4 Experimental Section ........................................................73
4.1 Analytical Methods ..................................................................73
4.1.1 General Analytical Methods ..................................................73
4.1.2 Cyclic Voltammetry ................................................................ 73
4.1.3 Spectroelectrochemistry .......................................................74
4.1.4 UV/Vis Spectroscopy .............................................................74
4.1.5 Fluorescence Spectroscopy .................................................75
4.1.6 Transient Absorption Measurements ................................... 76
4.1.7 Synthesis ................................................................................81









4.2 Synthesis .................................................................................81
4.2.1 General Experimental Procedures ....................................... 81
4.2.1.1 Palladium Catalysed Amination of Aryl Halides (GP1) ...81
4.2.1.2 Hagihara-Coupling (GP2) ...................................................81
4.2.2 Synthesis of Precursors ........................................................ 82
4.2.3 Synthesis of Reference Chromophores ............................. 102
4.2.4 Synthesis of Cascades 105

5 Literature ..........................................................................115

6 Table of Formulas ...........................................................123
6.1 Reference Chromophores ....................................................123
6.2 Cascades ................................................................................123
6.3 Precursors .............................................................................124

7 Summary ..........................................................................127

8 Zusammenfassung ..........................................................129

Appendix ..............................................................................131
Publikationen .................................................................................131
Danksagung ...................................................................................132
Erklärung ........................................................................................135






Abbreviations

Ac acridine
ATP adenosine triphosphate
CR charge recombination
CS charge separation / charge separated
1CS excited singlet charge separated
3CS excited triplet charge separated
CT charge transfer
1CT excited singlet charge transfer
3CT excited triplet charge transfer
CV cyclic voltammetry / cyclic voltammogram
CW continuous white light
dba trans,trans-dibenzylideneacetone
DMF dimethylformamide
DSSC dye sensitised solar cells
ET electron transfer
Fc ferrocene
H Hoechst 33258
HT hole transfer
ISC intersystem crossing
IVCT intervalence charge transfer
LFP laser flash photolysis
NADP nicotinamide adenine dinucleotide phosphate
MeCN acetonitrile
NIR near infrared
OD optical density
PET photoinduced electron transfer
PhCN benzonitrile
PMT photomultiplier
S singlet ground state 0
S excited singlet state 1