Benzanthrone sulfides: synthesis, solvatochromism characterization and analysis of experimental photophysical parameters and theoretical calculations

In this paper the synthesis, characterization, and photophysical properties of benzanthrone-derived sulfides are discussed. The compounds were synthesized using a practical method of nucleophilic aromatic substitution reactions of 3-bromobenzanthrone with thiols. Structural characterization was conducted using nuclear magnetic resonance (NMR) and Fourier-transform (FTIR) spectroscopy and high-resolution mass spectrometry, confirming the chemical structures. The crystal structure of a compound was determined via X-ray diffraction, revealing π-π stacking interactions and intermolecular hydrogen bonding. Photophysical analysis showed solvatochromic effects (emission of light upon excitation from 507 nm in benzene to 591 nm in ethanol) and attributed fluorescence to intramolecular charge transfer. Computational analysis using DFT calculations provided further insights into the compounds' properties, including excited state energies and the potential for efficient intersystem crossing. Overall, the research provides a comprehensive understanding of the newly synthesized benzanthrone alkyl and aryl sulfides as well as a phenylselanyl derivative. The photophysical properties, charge transfer characteristics observed in the compounds and the solvatochromic effects exhibited by the compounds suggest their potential to be utilized for developing sensors for detecting environmental changes, chemical substances or biological targets.