|
|||||
|
|
Circularly Polarized Luminescence and Circular Dichroism of Bichromophoric Difluoroboron-β-diketonates: Inversion and Enhanced Chirality Based on Spatial Arrangements and Self-Assembly |
|
| Authors: | Joy Ann Panis Prof Marine Louis Arnaud Brosseau Shouhei Katao Florencio de los Reyes Prof Takuya Nakashima Dr Rémi Métivier Dr Clémence Allain Prof Tsuyoshi Kawai |
| Institution: | 1. Photonic and Reactive Molecular Science Laboratory, Division of Materials Science, Nara Institute of Science and Technology, Ikoma, Nara, Japan
Université Paris-Saclay, ENS Paris-Saclay, CNRS, PPSM, 91190 Gif-sur-Yvette, France;2. Photonic and Reactive Molecular Science Laboratory, Division of Materials Science, Nara Institute of Science and Technology, Ikoma, Nara, Japan;3. Université Paris-Saclay, ENS Paris-Saclay, CNRS, PPSM, 91190 Gif-sur-Yvette, France |
| Abstract: | We synthesized two bichromophoric difluoroboron-β-diketonates (DFB) connected in para and meta positions by using cyclohexane diamine as a chiral bridge ( para and meta (R/S)-CyDFB ). TD-DFT calculations revealed that the variation in connectivity of the DFB units leads to different spatial arrangements and a chirality inversion of the bichromophoric DFB. Higher gabs values were obtained in (R/S)-CyDFB connected in para as compared to meta position. Aggregation of para (R/S)-CyDFB in mixture of solvents increase the glum values as compared to its monomeric form. Ultrasonication and heating induced the formation of highly ordered nano-helical wires of para (R/S)-CyDFB that increased the glum values to 0.015. On the other hand, meta (R/S)-CyDFB failed to form highly ordered self-assembled wires due to hindered H-binding sites. These observations indicate that the chiroptical properties of DFB bi-chromophore system can be modulated with self-assembly and spatial arrangement of the chromophores. |
| Keywords: | bichromophores circularly polarized luminescence circular dichroism difluoroboron-β-diketonates self-assembly |