Synthesis and Spectroscopic Investigation of a Series of Push-Pull Boron Dipyrromethenes (BODIPYs).
A series of push-pull BODIPYs bearing multiple electron-donating and electron-acceptor groups were synthesized regioselectively from 2,3,5,6,8-pentachloro-BODIPY, and characterized by NMR spectroscopy, HRMS, and X-ray crystallography. The influence of the push-pull substituents on the spectroscopic and electrochemical properties of BODIPYs was investigated. Bathochromic shifts were observed for both absorbance (up to 37 nm) and emission (up to 60 nm) in different solvents upon introduction of the push-pull moieties. DFT calculations, consistent with the spectroscopic and cyclic voltammetry studies, show decreased HOMO-LUMO energy gaps upon the installation of the push-pull moieties. BODIPY 7 bearing thienyl groups on the 2 and 6 positions showed the largest λmaxfor both absorption (635-653 nm) and emission (706-707 nm), but also the lowest fluorescence quantum yields. All BODIPYs were nontoxic in the dark (IC50> 200 μM) and showed low phototoxicity (IC50> 100 μM, 1.5 J/cm2) toward human HEp2 cells. Despite the relatively low fluorescence quantum yields, the push-pull BODIPYS were effective for cell imaging, readily accumulating within cells and localizing mainly in the ER and Golgi. Our structure-property studies can guide future design of functionalized BODIPYs for various applications, including bioimaging and in dye-sensitized solar cells.
Department of Chemistry, Louisiana State University , Baton Rouge, Louisiana 70803, United States.
Sunting
S
Xuan
Department of Chemistry, Louisiana State University , Baton Rouge, Louisiana 70803, United States.
Ning
N
Zhao
Department of Chemistry, University of Houston , Houston, Texas 77204, United States.
Xiangyi
X
Ke
Department of Chemistry, Louisiana State University , Baton Rouge, Louisiana 70803, United States.
Zehua
Z
Zhou
Department of Chemistry, Louisiana State University , Baton Rouge, Louisiana 70803, United States.
Frank R
FR
Fronczek
Department of Chemistry, University of Houston , Houston, Texas 77204, United States.
Karl M
KM
Kadish
Department of Chemistry, Louisiana State University , Baton Rouge, Louisiana 70803, United States.
Kevin M
KM
Smith
Department of Chemistry, Louisiana State University , Baton Rouge, Louisiana 70803, United States.
M Graça H
0000-0002-4429-7868
MG
Vicente
D001895:Boron / Q000737:chemistry*; D018360:Crystallography, X-Ray; D005453:Fluorescence; D015394:Molecular Structure; D011162:Porphobilinogen / Q000031:analogs & derivatives* / Q000737:chemistry; D011789:Quantum Theory; D013057:Spectrum Analysis / Q000379:methods*
C507544:dipyrromethene; D011162:Porphobilinogen; D001895:Boron