Photoinduced electron and energy dynamics in architecturally designed molecular assemblies containing C₆₀-fullerene

Abstract

The studies presented in this thesis describes the excited state dynamics of electron and energy transfer in one- and two-dimensional π-conjugated molecular constructs with fullerenes as electron accepting chromophores. -- This thesis first starts with the energetics and dynamical processes in the excited state of π-conjugated OPV/OPE oligomers following photon capture. Systematic analysis and characterization of the excited states formed after excitation includes the detailed quantitative understanding of the structural, electronic and vibronic parameters of π-conjugated OPV/OPE oligomers, as well as the substituent and orientation effects that dictate radiative, non-radiative relaxation pathways and the reaction dynamics of these transient excited states. -- With the detailed understanding of the excited state properties of π-conjugated OPV/OPE bridges, the photo-induced electron and energy transfer in the π-bridged C₆₀ systems [A-(π-B)C/L-A] was undertaken. A major portion of the research centered on diphenylamino derivatized molecular assemblies. The excited states of molecular assemblies containing phenylamino moieties are known to be complex and many facets of dynamics are still controversial. Systematic investigations of the donor substituent effect on the excited state dynamics and the photo-induced electron and energy transfer in the donor substituted (π-B)-bridged C₆₀ systems (A-[π-(D)BC]n-A) were scrutinized. Ultimately, this research should teach us how to engineer molecules in the potential opto-photonic device applications, i.e. photosynthetic devices that convert photonic energy into chemical energy. -- With the increased understanding of the ground and excited state properties of π-conjugated OPV/OPE oligomers with donor substituents, the last chapter is to assess the performance of two-dimensional H-shaped OPV/OPE chromophores with electron donor and acceptors as potential sensors for specific analytes.