Ab initio investigation of molecular junctions with various stereoisomers and substituents

• Applicant: Professor Dr. Martin Albrecht
• Subject Area: Theoretical Chemistry: Electronic Structure, Dynamics, Simulation
• Term: from 2004 to 2006
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5431735

The project suggests to investigate molecular junctions as they can be recently obtained in break-junction experiments. Many influences might control the electric current through such a junction. Given its nanoscale, theoretical investigations must be based on quantum mechanical methods. In this project we analyze the transmission properties of molecular junctions as derived from a recently developed quantum chemical approach to the Green's function. The method consists of a full ab initio scheme which renounces modelling and effective parametrization. It has been tailored into a flexible analytic tool which allows to focus on the very local processes believed to be essential. The project described here strives to apply this approach to the most urgent questions of how the electric current through a molecular junction might be controlled by various influences reaching from the very geometric arrangement of the junction via particular changes in the shape of the molecule (stereoisomerization) to chemical substitution. All these points are of paramount importance for the further understanding and development of single molecule devices. The project thus bridges a gap from fundamental research to nano engineering.

• DFG Programme: Research Grants
• Participating Person: Professor Dr. Michael Dolg