Jump to main content
Jump to site search
Access to RSC content Close the message box

Continue to access RSC content when you are not at your institution. Follow our step-by-step guide.

Issue 7, 2009
Previous Article Next Article

Photophysics and stability of cyano-substituted boradiazaindacenedyes

Author affiliations


The solvatochromic photophysical properties of two fluorescent, cyano-substituted BODIPY dyes8-(4-bromophenyl)-3,4,4,5-tetracyano-4-bora-3a,4a-diaza-s-indacene (4CN) and 8-(4-bromophenyl)-3,5-dicyano-4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (2CN)—have been studied in various solvents by UV–vis spectrophotometry and steady-state and time-resolved fluorometry. These two BODIPY analogues have comparable photophysical properties, implying that displacement of F by CN at boron has a negligible effect. Both compounds have high fluorescence quantum yields Φf (0.65–0.90 for 4CN and 0.63–0.88 for 2CN) in the solvents studied and display mono-exponential fluorescence decay profiles in nonprotic solvents. A new, generalized treatment of the solvent effect based on four mutually independent, empirical solvent scales (dipolarity, polarizability, acidity, and basicity of the medium) indicates that solvent polarizability and, to a lesser degree, solvent (di)polarity are crucial factors causing the solvent-dependent shifts of the UV–vis absorption and fluorescence emission. The rate constants of radiative deactivation (kf) are nearly independent of the nonprotic solvent [kf = (1.4 ± 0.1) × 108 s−1 for 4CN and (1.5 ± 0.2) × 108 s−1 for 2CN]. Both compounds undergo a color change in polar aprotic solvents (acetone, acetonitrile, and N,N-dimethylformamide), which can be stopped by addition of HClO4. The kinetics of this color change indicates that the decomposition of these cyano-substituted BODIPY compounds is complex.

Graphical abstract: Photophysics and stability of cyano-substituted boradiazaindacene dyes

Back to tab navigation

Supplementary files

Article information

12 Mar 2009
27 Apr 2009
First published
12 May 2009

Photochem. Photobiol. Sci., 2009,8, 1006-1015
Article type

Photophysics and stability of cyano-substituted boradiazaindacene dyes

K. Cieślik-Boczula, K. Burgess, L. Li, B. Nguyen, L. Pandey, W. M. De Borggraeve, M. Van der Auweraer and N. Boens, Photochem. Photobiol. Sci., 2009, 8, 1006
DOI: 10.1039/B905054J

Social activity

Search articles by author