Decoding structural rigidity and charge-transfer polarization in barbituric-acid-based donor-π-acceptor chromophores

Area of Science:

• Computational Chemistry
• Materials Science
• Photovoltaics

Background:

• Donor-π-acceptor chromophores are crucial for organic electronic devices.
• Understanding excited-state properties is key to designing efficient photovoltaic materials.
• Barbituric acid derivatives offer tunable electronic characteristics.

Purpose of the Study:

• To investigate the structure-property relationships of two barbituric-acid-based chromophores.
• To elucidate the excited-state electronic redistribution and photovoltaic relevance.
• To assess their potential as dye sensitizers for dye-sensitized solar cells (DSSCs).

Main Methods:

• Systematic investigation using Density Functional Theory (DFT) and time-dependent DFT.
• Solvent-dependent polarizable continuum model (PCM) calculations.
• Excited-state geometry optimizations, Mulliken charge analysis, electrostatic potential mapping, and frontier molecular orbital analysis.

Main Results:

• Compound 1 exhibited locally excited (LE) character with minimal structural changes and weak solvent sensitivity.
• Compound 2 displayed significant intramolecular charge transfer (ICT) with pronounced bond modulation and enhanced polarization in polar media.
• Compound 2 showed favorable photovoltaic descriptors, including electron-injection driving force and light-harvesting efficiency, suitable for DSSCs.

Conclusions:

• Compound 2 is a promising candidate for dye sensitizers in DSSCs due to its efficient charge transfer and absorption properties.
• Compound 1's limited charge separation and electron-injection capability restrict its photovoltaic applications.
• Computational methods effectively predict the performance of chromophores for solar cell applications.