- BODIPY based A-D-A molecules: Effect of CF3 group substitution at meso phenyl group
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Two pairs of A-D-A molecules have been synthesized with fluorene and benzodithiophene as the central donor subunits and terminal BODIPY units, functionalized with either a 4-methylphenyl or 4-trifluoromethylphenyl group at the meso position. The effect of the para substituent of the meso phenyl group on the photophysical properties of these molecules is studied through steady state absorption and fluorescence spectroscopy as well as femtosecond transient absorption and time resolved fluorescence spectroscopy techniques. Applicability of these molecules as donors in solution processed solar cell active layers was investigated through time resolved microwave conductivity measurements on blends with PC60BM acceptor, which shows a varying yield of charge transfer with choice of substituent. Transient absorption spectroscopy is then employed to investigate the role of the 4-trifluoromethylphenyl group in altering the efficiency of charge transfer from these A-D-A molecules to PC60BM. The results show a consistent picture of picosecond charge transfer and a component of a few hundred ps geminate recombination that results in a small yield of long-lived free charges optimized for the methylphenyl derivatives.
- Johnson, Justin C.,Larson, Bryon W.,Ramamurthy, Praveen C.,Tarafdar, Gourav
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- Excitation-Wavelength-Dependent Light-Induced Electron Transfer and Twisted Intramolecular Charge Transfer in N, N-Bis(4′- tert-butylbiphenyl-4-yl)aniline Functionalized Borondipyrromethenes
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A series of bis(4′-tert-butylbiphenyl-4-yl)aniline (BBA) functionalized borondipyrromethene (BODIPY) dyads, Dyads 1-3, containing the BBA group tethered to BODIPY moiety either directly or through a phenyl or alkynyl phenyl spacers are synthesized, and the light-mediated charge transfer within the chromophores has been systematically investigated. The crystal structure of Dyad-1 showed a tilt of 44.2° between the BODIPY and BBA molecular planes and intermolecular C-H···πinteractions with these moieties. Cyclic voltammetric and computational studies showed that the BBA moiety can act as the electron donor (D) and BODIPY as the electron acceptor (A) and the optical absorption studies revealed that an increase in the conjugation of the linker from Dyad-1 to Dyad-2 resulted in bathochromic shifts. Steady-state fluorescence studies involving photoexcitation of the BBA moiety at 326 nm resulted in the decrease in fluorescence intensity of the BBA, indicating the possibility of sequential occurrence of faster photoinduced energy transfer (PEnT) followed by the photoinduced electron transfer (PET) or solely PET within the dyads, and the driving forces of the charge separation were calculated to be exothermic in all of the employed solvents. Parallel time-resolved fluorescence experiments involving the excitation of BBA moiety also supported the occurrence of charge separation in these dyads. Interestingly, excitation of the BODIPY moiety of Dyad-1 and Dyad-2 at 490 nm in solvents of increasing polarity leads to a red-shifted BODIPY emission with weakened intensity. This spectral behavior indicated the occurrence of emission from the locally excited (LE) state in nonpolar solvents, whereas formation of an LE state followed by the rotation of the chromophores at the D-A bond leads to a low energy twisted intramolecular charge transfer state (TICT), resulting in a charge-separated state BBA+?-BODIPY-? in polar solvents. Furthermore, the hydrophobicity studies involving the solutions of dyads in admixtures of polar tetrahydrofuran (THF) and nonpolar hexanes revealed that when the fraction of hexanes in these mixtures is increased, the emission of BODIPY moiety was observed to be blue-shifted and exhibited enhanced intensity supporting the occurrence of TICT in these dyads.
- Gangada, Suneel,Ramnagar, Ramya Athira,Sangolkar, Akanksha Ashok,Pawar, Ravinder,Nanubolu, Jagadeesh Babu,Roy, Partha,Giribabu, Lingamallu,Chitta, Raghu
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p. 9738 - 9750
(2020/11/30)
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- Taurine substituted bodipy fluorescent compound and preparation method and application thereof
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The invention provides a taurine substituted bodipy fluorescent compound, and further provides a preparation method of the taurine substituted bodipy fluorescent compound. The method comprises the following steps: reacting 8-(4-position substituted phenyl)-3, 5-diiodo-1, 2, 6, 7-tetra-substituted bodipy and 1,2-disubstituted taurine under the conditions of an additive, a catalyst and a solvent toobtain 8-(4-position substituted phenyl) 3-iodo-5-(2-ethanesulfonic acid) amine)-1,2,6,7-tetra-substituted bodipy and 8-(4-position substituted phenyl) 3,5-bis((2-ethanesulfonic acid) amine)-1,2,6,7-tetra-substituted bodipy. According to the taurine substituted bodipy fluorescent compound, by a cheap metal catalyzed direct C-X/N-H activating method, taurine with biological activity is introducedat a 3,5 activated site of star fluorescent molecule bodipy, and therefore, a novel fluorescent molecule framework is formed.
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Paragraph 0052; 0053; 0054; 0055
(2018/09/11)
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- Indole-BODIPY: A turn-on chemosensor for Hg2+ with application in live cell imaging
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A new BODIPY, 2-(bis(1-methyl-1H-indol-3-yl)methyl)-4,4-difluoro-4-bora-3a,4a-diaza-s-indacene bearing bis(1-methyl-1H-indol-3-yl)methyl unit at the β-pyrrolic position acting as a 'turn-on' chemosensor for Hg2+ in solution as well as in HeLa cells, is synthesized. The 'off' state of the probe is proposed to be a result of a photoinduced electron transfer (PET) process which gets inhibited in the presence of Hg2+ ions, leading to the 'on' state. We propose that the detection of Hg2+ ions proceeds via the interaction of the π-electron density of the electron rich indolic units of the BODIPY group with that of the acidic Hg2+ ions, restricting the PET. The sensing protocols are established by various spectroscopic/electrochemical/DFT studies.
- Kaur, Navdeep,Kaur, Paramjit,Bhatia, Gaurav,Singh, Kamaljit,Singh, Jatinder
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p. 82810 - 82816
(2016/10/22)
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- Synthesis, structure, photophysical, electrochemical properties and antibacterial activity of brominated BODIPYs
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A series of mono- and di-brominated BODIPYs (1-5) was synthesized and characterized with a view to study the performance of dyes towards antibacterial activity. Regioselective bromination at the 2- and 2,6-positions of the BODIPY core was achieved with quantitative yield. The bromination of meso-(4-hydroxyphenyl) BODIPY (5) yielded an unexpected dibromo derivative, where the bromine groups were installed at the 3,5-positions of the phenyl ring rather than the 2,6-positions of the BODIPY core, which is confirmed and supported by UV-visible, fluorescence, and 1H NMR spectroscopic analyses, electrochemical studies, and also by single crystal X-ray crystallography. We observed a red shift of ~16 nm in the absorption and 20-29 nm in the emission spectra in CH2Cl2 for the installation of each bromine group at the BODIPY core. The small difference between the first reduction potentials of the parent and dibromo derivative (5 and 5b) reveal that dibromination does not occur on the pyrrolic moiety. The intermolecular interactions involving C?H, F?H, H?H, and Br?H are the key factors in stabilizing the molecular crystal packing. The antibacterial properties of these dyes were investigated and the brominated derivatives showed better antibacterial effects than their corresponding parent BODIPYs, particularly the unusual dibromo derivative, 5b.
- Prasannan, Dijo,Raghav, Darpan,Sujatha, Subramaniam,Hareendrakrishna Kumar, Haritha,Rathinasamy, Krishnan,Arunkumar, Chellaiah
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p. 80808 - 80824
(2016/09/09)
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- Scope and limitations of the liebeskind-srogl cross-coupling reactions involving the biellmann BODIPY
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Several new examples of meso-(het)arylBODIPY were prepared via the Liebeskind-Srogl (L-S) cross-coupling reaction of the Biellmann BODIPYs (1a,b) and aryl- and heteroarylboronic acids in good to excellent yield. It was shown that this reaction could be ca
- Betancourt-Mendiola, Lourdes,Valois-Escamilla, Ismael,Arbeloa, Teresa,Ba?uelos, Jorge,López Arbeloa, I?igo,Flores-Rizo, Juan O.,Hu, Rongrong,Lager, Erik,Gómez-Durán, César F. A.,Belmonte-Vázquez, José L.,Martínez-González, Mayra R.,Arroyo, Ismael J.,Osorio-Martínez, Carlos A.,Alvarado-Martínez, Enrique,Urías-Benavides, Arlette,Gutiérrez-Ramos, Brenda D.,Tang, Ben Zhong,Pe?a-Cabrera, Eduardo
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p. 5771 - 5782
(2015/06/16)
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- α-fused dithienyl BODIPYs synthesized by oxidative ring closure
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Both symmetrical and unsymmetrical α-fused dithienyl-BODIPY dyes have been prepared by oxidative ring closure induced by anhydrous FeCl3. Extension of the π-system in the fused BODIPY leads to a progressive shift to 579 and 665 nm respectively
- Heyer, Elodie,Retailleau, Pascal,Ziessel, Raymond
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supporting information
p. 2330 - 2333
(2014/05/20)
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