From Molecules to Devices: Supramolecular Interactions in Materials for Advanced Applications
Abstract
To fully exploit the promise of molecular materials for advanced applications a thorough understanding of supramolecular structure-properties relationships is needed, a non-trivial problem because non-additive, collective behavior appears as a result of intermolecular interactions. We present a model for interacting polar and polarizable molecules that applies to clusters (films, crystals, aggregates...) of D-Pi- A molecules for molecular electronics and/or NLO applications. The model is based on a two-state description of the isolated molecules, validated by an extensive spectroscopic study of solvated molecules. Classical electrostatic interactions in molecular clusters are then accounted for in a bottom-up theoretical approach that parallels the synthetic strategy. We demonstrate that the molecular polarity, and hence all molecular properties are largely affected by supramolecular interactions: the same molecule behaves in qualitatively different ways in different environments. Even more important, brand new phenomena appear in molecular materials with no counterpart at the molecular level. These phenomena largely extend the scope of potential application of molecular materials. In particular, in lattices with attractive interactions, large bistability regions appear where the material can be switched between two different regimes by slight variations of external conditions. In the proximity of the bistable region, important collective effects show up in the excitation spectrum, and the absorption of a single photon directly drives a concerted multielectron transfer occurring on several nearby molecules.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 2004
- Accession Number
- ADA442531
Entities
People
- Anna Painelli
- Francesca Terenziani
Organizations
- University of Parma