Solid-emissive boron–fluorine derivatives with large Stokes shift
摘要:
Novel BOPIM (boron 2-(2'-pyridyl)imidazole complex) derivatives with large Stokes shift were efficiently synthesized through two-step reactions, starting from commercially available 2-pyridinecarboxaldehyde and alpha-diketone. The dyes exhibit high fluorescent intensity in solution and also in solid state due to the intermolecular non-planar interactions. According to X-ray single crystal measurements, the non-covalent interactions (such as C-H center dot center dot center dot F-B, etc.) play important role in inhibiting planar pi-pi stacking, and the existence of terminal phenyl rings increases the electronic density of pi system, which facilitates the charge transfer from the electron-donating pi system to the electron-accepting boron moiety. DFT calculation based on X-ray crystallographic analysis was carried out for compound 2, giving consistent results with photophysical measurements. (C) 2012 Elsevier Ltd. All rights reserved.
between photochromic diarylethenes and solid-emissive Boron–Fluorine dye. Photochromism of the self-assemblies results in slight modulation of the Boron–Fluorine dye's fluorescence in dilute solution, but high-contrast ON/OFF fluorescence switching in nanoparticles and in the solid state. During this process, intermolecular hydrogenbonds between the carboxyl units on diarylethenes and the imidazole ring