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| Danksagungen | |
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| Zusammenfassung | |
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| Abstract | |
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| Introduction | |
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| Goals, text guide and nomenclature | |
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| Absorption Spectra and Electronic Structure of D-A Biphenyls | |
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| Introduction | |
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| Experimental | |
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| Results and Discussion | |
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| Composite molecule approach for donor-acceptor biphenyls I-III | |
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| UV/VIS absorption spectra and their derivatives | |
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| Linear dichroic absorption spectra | |
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| Comparison of spectral data with calculated results | |
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| Conclusions | |
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| References | |
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| Fluorescence and Photophysics of D-A Biphenyls at 298 K | |
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| Introduction | |
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| Experimental Section | |
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| Synthesis of the compounds | |
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| Solvents | |
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| Steady state absorption | |
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| Steady state fluorescence | |
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| Fluorescence quantum yields | |
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| Fluorescence lifetimes | |
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| Quantum chemical calculations | |
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| Results and Discussion | |
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| Steady state spectra | |
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| Excited state dipole moments from solvatochromic plots | |
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| Photophysics | |
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| Photophysical evidence for [superscript 1]L[subscript a]-type fluorescence | |
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| Structural and solvent dependence of nonradiative rates | |
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| Ratios of radiative rate constants as indicators for angular relaxations | |
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| Excited state conformational equilibrium for III | |
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| Theoretical calculations | |
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| Twist potentials in S[subscript 0] | |
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| Electronic nature of S[subscript 1] | |
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| Molecular structure in S[subscript 1] | |
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| Conclusions | |
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| References and Notes | |
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| Sub-picosecond Transient Absorption of D-A Biphenyls. Intramolecular Control of the Excited State Charge Transfer Processes | |
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| Introduction | |
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| Experimental | |
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| Materials | |
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| Picosecond pump-probe experiments | |
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| Correction and fitting of the results | |
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| Quantum chemical calculation of the transient spectra | |
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| Results | |
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| Steady-state spectra and expectations | |
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| Transient absorption measurements | |
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| n-Hexane solutions | |
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| Acetonitrile solutions | |
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| Diethylether solutions | |
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| Triacetine solutions | |
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| Discussion | |
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| Excited state absorption and gain bands | |
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| Assignments of the absorbing and emitting species to two states | |
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| Effects of solvent polarity and twist angle | |
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| Structure relaxation | |
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| Kinetics of state interconversion [superscript 1]FC[right arrow][superscript 1]CT | |
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| Conclusions | |
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| References | |
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| Fluorescence Polarization Spectroscopy of D-A Biphenyls at 77K. The Electronic Relaxations | |
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| Introduction | |
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| Experimental | |
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| Polarization and millisecond luminescence spectroscopy | |
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| Results and Discussion | |
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| References | |
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| Temperature Dependent Study of Excited State Conformational Relaxations in D-A Biphenyls Using Steady-State and Time-Resolved Fluorescence | |
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| Introduction | |
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| Experimental | |
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| Low temperature measurements | |
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| Band shape analysis | |
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| Global analysis of emission decays | |
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| Results and Discussion | |
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| Temperature dependence of radiative back charge transfer and excited state relaxations for the D-A biphenyls I-III | |
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| Energetics from fluorescence band shape analysis | |
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| Analysis of the fluorescence lifetimes and quantum yields | |
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| Temperature dependence of the conformational equilibrium in the excited state [superscript 1]CT of the strongly pretwisted D-A biphenyl III in diethylether | |
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| The method to recover dual fluorescence bands and to derive the reaction rate constants by global analysis of emission decays | |
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| Quantitative characterization of the excited state conformational equilibrium between two charge transfer species CT and CTR | |
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| Conclusion | |
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| References and Notes | |
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| Pressure and Temperature Dependent Fluorescence of D-A Biphenyls. The Separation of Viscosity and Thermal Control of the Conformational Photoreaction in the Highly Twisted Compound | |
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| Introduction | |
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| Experimental | |
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| High pressure equipment | |
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| Ti:Sapphire Laser | |
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| Results and Discussion | |
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| Viscosity and temperature influence on the fluorescence and excited state relaxations of I-III in triacetine (TAC) | |
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| Analysis of reaction rate constants and its boundary conditions | |
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| The method to distinguish between viscosity and thermal control of a photoreaction | |
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| Separated thermal activation energy and viscosity dependence of the conformational photoreaction in III | |
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| Concluding Remarks | |
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| References | |
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| The Influence of Conformation and Energy Gaps on Optical Transition Moments in D-A Biphenyls | |
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| Introduction | |
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| Experimental and Semiempirical Calculations | |
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| Results and Discussion | |
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| Experimental transition dipole moments | |
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| Electronic coupling between [superscript 1]ET and [superscript 1]L[subscript a] in dependence of the twist-angle | |
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| Description of transition moments with reference states | |
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| Influence of structural relaxations other than [open phi][subscript D-A] twisting on M[subscript CT] | |
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| Influence of the [superscript 1]ET-[superscript 1]L[subscript a] energy gap on M[subscript CT] | |
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| Evaluation of S[subscript 0] and S[subscript 1] twist angles in solvents | |
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| Concluding Remarks | |
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| References and Notes | |
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| Conformation and Energy Gap Dependent Electron Transfer Interactions in Flexible D-A Biarls: The Case of Two Twisted 9-(dimethylanilino) phenanthrenes | |
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| Introduction | |
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| Experimental and Calculations | |
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| Results | |
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| Spectroscopic transition moments and energies | |
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| Quantum chemical calculations | |
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| Discussion | |
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| Influence of electron transfer interactions on absorption and emission bands | |
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| Squared transition moments as indicators for molecular and electronic structure | |
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| Conclusions | |
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| References and Notes | |
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| Possible Applications of D-A Biphenyls as Fluorescent Probes | |
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| Introduction | |
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| Experimental | |
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| Measurements of pH | |
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| Results and Discussion | |
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| Micropolarity | |
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| Transition temperature from liquid to solid (Tg) | |
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| Protic solvents | |
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| Sensitive and self-calibrating sensing of pH in aqueous solution | |
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| Conclusion | |
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| References and Notes | |
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| Implications to Solar Energy Conversion | |
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| Introduction | |
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| Experimental | |
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| Preparation of polymer films | |
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| Results and Discussion | |
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| Requirements for low lying and highly fluorescent [superscript 1]CT states in D-A biaryls | |
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| Which host environment is favourable for Fluorescent Solar Concentrators (FSC) | |
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| Solar Perspectives | |
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| Fluorescent Solar Concentrators using planar or moderately twisted D-A biaryls | |
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| Towards Electron Transfer Initiated Photocatalysis (ETIP) using twisted D-A biaryls | |
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| References | |
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| Final Conclusions | |
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| Appendix A | |
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| Glossery of Abbreviations | |
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| List of Publications | |
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| Lebenslauf | |