Molecular structure, binding, and disorder in TDBC-Ag plexcitonic assemblies

Area of Science:

• * Nanoscience and Materials Science
• * Physical Chemistry
• * Spectroscopy

Background:

• * Plexcitonic assemblies are hybrid materials coupling plasmonic nanoparticles with molecular emitters.
• * Strong coupling leads to hybridized upper and lower polariton branches.
• * Understanding molecular geometry at metal interfaces is key but challenging.

Purpose of the Study:

• * To comprehensively characterize the structure of a TDBC-silver nanodisk plexciton.
• * To elucidate how molecular packing and conformation change upon adsorption.
• * To establish a structural benchmark for geometry-dependent photophysics.

Main Methods:

• * Nuclear Magnetic Resonance (NMR) spectroscopy
• * Terahertz-Raman spectroscopy
• * Density Functional Theory (DFT) calculations

Main Results:

• * TDBC monomers adopt an asymmetric sulfobutyl chain conformation.
• * J-aggregates show symmetric chain alternation, distorted upon adsorption.
• * Specific Raman modes and NOESY peaks indicate aggregation geometry and adsorption effects.

Conclusions:

• * Molecular geometry and interfacial arrangement in TDBC-silver plexcitons are constrained.
• * Adsorption on silver nanodisks disrupts long-range order in TDBC J-aggregates.
• * Provides a structural basis for understanding photophysics in exciton-plasmon systems.