Synthesis, Crystal Structure, and Photophysical Properties of Bromothiophene‐Functionalized BF₂‐Curcuminoid as a Versatile Building Block

Abstract

A novel bromothiophene‐functionalized BF2‐curcuminoid (BTC‐BF2) is synthesized by Knoevenagel condensation reaction. The structure of BTC‐BF2 is determined by 1H‐nuclear magnetic resonance (1H NMR), 13C‐nuclear magnetic resonance (13C NMR), and high‐resolution mass spectrometry (HRMS). Moreover, a nearly coplanar single crystal structure is successfully obtained and form a mesh structure through intermolecular multiple C─H···F hydrogen bond interactions. As expected, as‐prepared BTC‐BF2 exhibits solvent‐dependent photophysical properties in solvents with different polarity and an intense red solid‐state fluorescence. Density functional theory calculations further verify the relationships between its intrinsic electronic features and the photophysical properties. For its potential application aspect, BTC‐BF2 shows a certain ability to generate singlet oxygen under irradiation with 530 nm green light. Moreover, BTC‐BF2 can be utilized as versatile building block to construct novel far‐red or NIR BF2‐curcuminoid complexes for widely biological applications.