On the dimers of Pseudoisocyanine

TL;DR

This study uses classical MD simulations and semiempirical methods to analyze the self-organization and electronic properties of pseudoisocyanine dimers, revealing insights into their spectral shifts and band widths.

Contribution

It provides a detailed computational analysis of pseudoisocyanine dimers, linking their conformations to spectral properties and vibrational effects for the first time.

Findings

Absorption band width mainly due to low frequency vibrations

Different dimer conformations show blue or red shifted absorption maxima

Site energy fluctuations are less significant in spectral broadening

Abstract

The self organization of pseudoisocyanine-dimers in dilute aqueous solutions is studied by classical MD simulations. The electronic structure of the dimer is evaluated with the semiempirical ZINDO method to determine the fluctuations of site energies and excitonic coupling. We study different dimer conformations with blue or red shifted absorption maxima as models for H and J-aggregates. The width of the absorption bands is mainly explained by low frequency vibrations whereas the fluctuations of site energies are less important.