FWF - Bichromophore Polysilane - Bichromophoric Polysilane Heterocycles and Cages

Project: Research project

Description

Electron transfer processes play a central role in many areas of science such as in natural photosynthesis, where
light absorption by appropriate antenna systems is followed by a series of energy and electron transfer steps in
order to convert solar energy into chemical energy. Recently, researchers have paid much attention to artificial
photosynthesis, what involves the mimicry of photosynthetic processes and the application of fundamental
principles in photosynthesis to energy conversion systems and molecular devices like wires or switches at a
molecular level. In this context electron transfer processes within various types of bichromophoric covalently
linked donor-bridge-acceptor (D-br-A) compounds were studied and electronic coupling between D and A groups
was found to primarily depend on the D/A distance and on the electronic properties of the bridge. So far, mainly
carbon based frameworks were utilized as linkers in such D-br-A systems. Among the heavier main group
element-catenated systems, however, especially the silicon based oligo- and polysilanes are likely to be potential
bridges due to extensive delocalization of -electrons along the silicon backbone. In fact, literature data available
so far support the assumption, that electronic coupling of D/A substituent groups via oligosilanes can be a rather
effective process especially in the case, when it is possible to control the conformation of the Si-Si skeleton in a
desired manner.
Within the current project, therefore, priorily unknown heterocyclic and cage like oligosilanes shall be synthesized
using especially tailored synthetic strategies. Strong substituentsubstituent electronic coupling in these model
compounds shall be realized by
- using sterically rigid oligosilane spacers
- carefully selecting the electronically active substituent groups and
- incorporating substituents directly into the conjugation path.
Furthermore, spectroscopic and electrochemical properties of the target compounds shall be investigated including
computational studies in order to gain deeper insight into structural and electronic features.
StatusFinished
Effective start/end date1/04/0931/03/12