Photophysical Properties of Borondipyrromethene Analogues in Solution
Citations Over TimeTop 1% of 2005 papers
Abstract
The photophysical properties of seven new 8-(p-substituted)phenyl analogues of 4,4-difluoro-3,5-dimethyl-8-(aryl)-4-bora-3a,4a-diaza-s-indacene (derivatives of the well-known fluorophore BODIPY) in several solvents have been studied by means of absorption and steady-state and time-resolved fluorimetry. For each compound, the fluorescence quantum yield and lifetime are lower in solvents with higher polarity owing to an increase in the rate of nonradiative deactivation. Increasing the electron withdrawing strength of the p-substituent on the phenyl group in position 8 also leads to lower fluorescence quantum yields and lifetimes. When the p-substituent on the phenyl group in position 8 is a tertiary amine [8-(4-piperidinophenyl), 8-(4-N,N-dimethylaminophenyl), and 8-(4-morpholinophenyl)], the low quantum yields of these compounds in more polar solvents can be rationalized by the inversion of the energy levels of an apolar, highly fluorescent and a polar, nonfluorescent excited state, where charge transfer from the tertiary amine to the BODIPY unit occurs. These amine analogues can be protonated at low pH in aqueous solution. Fluorescence titrations yielded pK(a) values of their conjugate ammonium salts which are in agreement with the electron donating tendency of the amine group: piperidino (4.15) > dimethylamino (2.37) > morpholino (1.47), with the pK(a) values in parentheses. The rate constant of radiative deactivation (k(f)) is the same for all compounds in all solvents studied (k(f) = 1.4 x 10(8) s(-1)).
Related Papers
- → A Sensitive and Selective Ratiometric Near IR Fluorescent Probe for Zinc Ions Based on the Distyryl−Bodipy Fluorophore(2008)250 cited
- → Facile functionalization of a fully fluorescent perfluorophenyl BODIPY: photostable thiol and amine conjugates(2011)48 cited
- → Cyclopropyl Substituents Transform the Viscosity-Sensitive BODIPY Molecular Rotor into a Temperature Sensor(2021)40 cited
- → Recent Advances of the Near-infrared Fluorescent aza-BODIPY Dyes(2016)36 cited
- Solid state emissive bodipy dyes with bulky substituents as spacers and a sensitive and selective ratiometric near IR fluorescent probe for zinc ions based on the distyryl-bodipy fluorophore(2010)