(S2→S0) and (S1→S0) luminescence of dimethylaminostyryl-β-diketonates of boron difluoride
摘要:
Spectral-luminescence properties of several dimethylaminostyryl-beta-diketonates of boron difluoride with different alpha-substituents have been investigated through stationary and time-resolved spectroscopy. Quantum chemistry studies of the structure of excited states of 2,2-difluoro-4-(4'-dimethylaminostyryl)-6-phenyl-1,3,2-dioxaborine have been performed. Two luminescence centers have been revealed for the compound under study: an intensive band in the red-orange region of the spectrum caused by an S-1-S-0 transition and a short-wave luminescence in the blue region of the spectrum caused by an S-2-S-0 transition. (C) 2014 Elsevier Ltd. All rights reserved.
A new class of dicyanoboron diketonates (B(CN)(2)) was synthesized and the photophysical properties were investigated. The B(CN)(2) complexes exhibited high molar absorption coefficients, large Stokes shifts, high photostability and low cytotoxicity. Especially, the emission of the B(CN)(2) extended into the deep red region. The extensive it conjugation and the presence of intramolecular charge transfer (ICT) transitions are responsible for their red-shifted emission. Their fluorescence are very sensitive to the polarity of the solvents. They are highly emissive in low polarity solvents, but weakly fluorescent in polar solvents. Cell imaging experiments demonstrated its potential application as a probe in bioorganisms due to its excellent imaging contrast. This strategy represents a facile approach to modulate the photophysical properties of dyes. (C) 2014 Elsevier Ltd. All rights reserved.