Molecular Foundry Seminar

"Structured Interfaces of Functional Amphiphiles:
Intramolecular Electronic Communication in Oriented Assemblies"

Professor Archita Patnaik, Indian Institute of Technology Madras
Tuesday, April 5th at 1:00 pm, Bldg. 67 - 3111

View the Foundry Seminar Schedule

Abstract:

Design, electronic structure modeling and synthesis of novel multifunctional amphiphiles with covalent and non-covalent / soft interactions have been our primary focus, culminating in possible structure–function relationships.  Understanding intermolecular interactions and controlled aggregate structure and dynamics in such unit molecular tectons have provided a rational designing for functional architectures. Adoption of soft chemical approaches for realizing highly oriented and dimensionally dictated functionalized mesostructures from unit photoreceptors will be discussed.

Realization of dye-dye aggregate formation in artificially synthesized dyes has been of continued interest in view of new avenues for electronic and photonic materials. Fullerene C60 being a fascinating 3D molecular entity with interesting optical and electronic properties, combining it with a photoactive azobenzene chromophore yielded molecular hybrids with novel photochemical, electrochemical and electronic properties. Tunable electronic properties of such a proton responsive dyad exhibiting frontier molecular orbital switching will be addressed. 

Molecules with potential for integration into devices at the nanometer scale have demonstrated promising theoretical and experimental functions. Following the advent of organic molecules acting as conductors, the idea of molecular rectification was realized from ‘metal|donor–bridge–acceptor| metal’ junctions with dyadic molecular architectures. In such molecular junctions, electrical rectification is defined in terms of the absence of inversion symmetry. A geometric asymmetry on the molecular skeleton creates a finite spatial electrostatic potential profile leading to a potential drop that regulates the induced rectification. In realizing this, the accompanying experiments were strongly corroborated by electronic structure calculation on fully optimized geometries through DFT and TD-DFT formalisms and through unconstrained molecular dynamics. The talk will elaborate on the donor - bridge - acceptor dyads taking fullerene C60- dyad rectifier as an example with a large rectification ratio.