Synthesis, spectroscopy, crystal structure, electrochemistry, and quantum chemical and molecular dynamics calculations of a 3-anilino difluoroboron dipyrromethene dye.
An asymmetrically substituted fluorescent difluoroboron dipyrromethene (BODIPY) dye, with a phenylamino group at the 3-position of the BODIPY chromophore, has been synthesized by nucleophilic substitution of 3,5-dichloro-8-(4-tolyl)-4,4-difluoro-4-bora-3a,4a-diaza-s-indacene. The solvent-dependent spectroscopic and photophysical properties have been investigated by means of UV-vis spectrophotometry and steady-state and time-resolved fluorometry and reflect the large effect of the anilino substituent on the fluorescence characteristics. The compound has a low fluorescence quantum yield in all but the apolar solvents cyclohexane, toluene, and chloroform. Its emission maxima in a series of solvents from cyclohexane to methanol are red-shifted by approximately 50 nm in comparison to classic BODIPY derivatives. Its oxidation potential in dichloromethane is at ca. 1.14 V versus Ag/AgCl. The absorption bandwidths and Stokes shifts are much larger than those of typical, symmetric difluoroboron dipyrromethene dyes. The values of the fluorescence rate constant are in the (1.4-1.7) x 10(8) s(-1) range and do not vary much between the solvents studied. X-ray diffraction analysis shows that the BODIPY core is planar. Molecular dynamics simulations show that there is no clear indication for aggregates in solution.
Qin
Wenwu
W
Department of Chemistry, Katholieke Universiteit Leuven, Leuven, Belgium.
Leen
Volker
V
Rohand
Taoufik
T
Dehaen
Wim
W
Dedecker
Peter
P
Van der Auweraer
Mark
M
Robeyns
Koen
K
Van Meervelt
Luc
L
Beljonne
David
D
Van Averbeke
Bernard
B
Clifford
John N
JN
Driesen
Kris
K
Binnemans
Koen
K
Boens
Noël
N
D000042:Absorption; D004396:Coloring Agents / Q000138:chemical synthesis* / Q000737:chemistry; D018360:Crystallography, X-Ray; D004563:Electrochemistry; D005740:Gases / Q000737:chemistry; D007700:Kinetics; D008958:Models, Molecular; D008968:Molecular Conformation; D011162:Porphobilinogen / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D011789:Quantum Theory; D012997:Solvents / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet
C538930:3-anilino difluoroboron dipyrromethene; D004396:Coloring Agents; D005740:Gases; D012997:Solvents; D011162:Porphobilinogen