Difluoroboron β-diketonate dye with intense red/near-infrared fluorescence in solutions and solid states

Difluoroboron beta-diketonate (BF(2)bdk) complexes have attracted much attention due to their outstanding photophysical properties. However, BF(2)bdk with near-infrared fluorescence usually suffer from emission quenching in solid state due to the pi-pi stacking in aggregation. Herein, we report a BF(2)bdk dye exhibiting donor-acceptor (D-A) structure with the difluoroboron moiety acting as the electron acceptor and the aminonaphthalene as the electron donor. It processes intense molar extinction coefficient, large Stokes shift and strong fluorescence in red/NIR region in both solution and aggregations. It was used for NIR imaging in living cells. (C) 2019 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.