Synthesis and spectroscopic properties of a novel perylenediimide derivative

A novel symmetric 3,4,9,10-perylenetetracarboxylic acid derivative (PDI1) dye based on thiophene donor group was synthesized and characterized by FT-IR and 1H NMR. Cyclic Voltammetry analysis is performed to determine the energy levels of the perylene derivative. Optical characteristics were determined by visible absorption and fluorescence emission spectra. Spectral behavior and fluorescence quantum yield of PDI1 have been measured in different solvents. The dye exhibits high fluorescence quantum yield ( Φf: 0.94-0.99). But the quantum yield PDI1 is very low in the n-butanol solution ( Φf: 0.12). The photophysical properties have important implications for use in a variety of electroactive and photovoltaic applications. A photovoltaic device was fabricated with PDI1 as transporting material. The conversion efficiency for DSSC sensitized by PDI1 is 0.0065%. PDI1 exhibits electrochromic behavior by switching between neutral (red) and oxidized (blue) states. Electron transfer capacity of PDI to the TiO2 was investigated by incorporation of dye as sensitizer in dye sensitized solar cell (DSSC). Soluble dye molecules are very important to prepare dye sensitized solar cell. Solubility was increased with thiophene group

Spectral properties and G-quadruplex DNA binding selectivities of a series of unsymmetrical perylene diimides

WOS: 000242913200001A series of new unsymmetrical perylene diimides have been synthesized to investigate their binding selectivities to G-quadruplex DNA structure, a unique four-stranded DNA motif, which is significant to the regulation of telomerase activity. The structures of the perylene diimides have been characterized by IR spectrophotometer, H-1 NMR, C-13 NMR, MS, TGA and time-resolved instruments. Spectrochemical behaviors have been investigated by visible absorption and fluorescence emission spectra. The spectral characterization of the compounds has been investigated in five common organic solvents of different polarity and in water (in 170 mM phosphate buffer at pH 6). Marked red shifts of absorbance and fluorescence emission bands of the compounds in aqueous solution are compared with the other organic solutions. The fluorescence quantum yields are determined low in more polar solvents and also calculated to be about less than about 0.05 in aqueous solution because of the aggregation effects. Photodegradation rate constants (k(p)) of the synthesized compounds have been compared under xenon lamp irradiation in acetonitrile solution. Binding abilities of the synthesized perylene diimides to different form of DNA strands have been investigated by visible absorption and fluorescence spectroscopy in the phosphate buffer solutions. Also, pH-dependent aggregation and G-quadruplex DNA binding selectivity of these ligands have been compared. Among these ligands, N-(2,6-diisopropylphenyl)-N'-(4-pyridyl)-perylene-3,4,9,10-tetracarboxylic diimide (PYPER) has been found to be the most selective interactive ligand for G-quadruplex formed in the G4'-DNA structure. PYPER has shown a significant selectivity to G4'-DNA which is comprised of d(TTAGGG) repeats, known as human telomeres, in the phosphate buffer at pH 6. The absorption maximum of the PYPER/G4'-DNA complex has given bathochromic shift of 7 nm with respect to the absorption maximum of DNA-free solution of PYPER in phosphate buffer at pH 6. Fluorescence quenching experiments between PYPER and G4'-DNA show that PYPER demonstrates about a 9.3-fold selectivity for binding to G4'-DNA versus ds-DNA base pairs with the bimolecular rate constant of 0.95 x 10(12) M-1 s(-1). (c) 2006 Elsevier B.V. All rights reserved

Studies on UV-vis and fluorescence changements in Co2+ and Cu2+ recognition by a new benzimidazole-benzothiadiazole derivative

WOS: 000349082200112A novel fluorescent sensor (BI-T) was synthesized by the coupling reaction of 2-(2-hydroxyphenyl)-7-phenyl-1H-benzimidazole-4-boronic acid with 4,7-dibromo-2,1,3-benzothiadiazole via Pd-catalysed Suzuki reaction. Its photophysical properties were investigated systematically in different solvents to analyze its potential usage in the fluorescence detection for transition metal ions such as Co2+ and Cu2+ in solutions. In benzonitrile solution, new absorption bands for complex structure of BI-T at 470 nm and 580 nm were appeared in the presence of Co2+ ions with respect to the uncomplexed form of the sensor absorption. BI-T sensor is usable for both Co2+ and Cu2+ sensation through "on-off" fluorescence change in benzonitrile. In ethanol solution, BI-T shows similar optical performances to detect Co2+ and Cu2+ ions. BI-T detects trace amount of transition metals in ethanol with estimated limit of detection around 4.1 x 10(-7) M and 5.5 x 10(-7) M for Co2+ and Cu2+ ions, respectively. Possible formation of metal-to-ligand charge transfer (MLCT) state during the titration with Co2+ ion is supported by the detection of long-lived species in the excited state. (C) 2014 Elsevier B.V. All rights reserved.Research Council of Celal Bayar, Manisa, TurkeyCelal Bayar University [2011-056]Financial support for this work was provided by the Research Council of Celal Bayar, Manisa, Turkey with the project number of 2011-056

Double connector to TiO2 surface in small molecule triphenyl amine dyes for DSSC applications

WOS: 000475587800070Two novel dyes 3a and 3b named triphenylamine groups containing donor-acceptor structural units have been explored to be used in dye sensitized solar cells as organic sensitizers. The absorption bands of the dyes were extended up to550nm with visible absorption maxima at 408-430nm and optical band gaps of 2.44-2.47eV. Compared to the methoxyphenyl-substituted dye, the introduction of triisopropylphenyl group instead of that increased fluorescence quantum yields and exhibited red-shift emission in chloroform. We have investigated the photovoltaic properties of DSSCs based on these metal free organic dyes. It has been found that the power conversion efficiency of DSSCs sensitized with methoxyphenyl based triphenylamine dye is higher than that for sensitized with triisopropylphenyl derivative.Ministry of Science and Technology of Turkey [16-DPT-002]This work was supported by the Ministry of Science and Technology of Turkey (Project Nr: 16-DPT-002)

Enhanced performance of ultra-thin polyaniline supercapacitor via aniline blue-WS SAMs with rich nucleation site

We report the ultrathin supercapacitor's superior performance via the vertically aligned one-dimensional polyaniline structure (1D PANI) growth on the fluorine-doped tin oxide (FTO) substrate. FTO electrodes were treated by the molecular-self assembly, and the effects of different self assembled monolayers (SAMs) on both the evolution of PANI and electrochemical performance were examined. We obtained 809.09 F g(-1) specific capacitance from similar to 120 nm thick PANI (at 20 mV s(-1) scan rate of cyclic voltammetry) via aniline blue water soluble SAMs modification. The supercapacitor's internal dynamics were clarified by a new equivalent circuit model developed from the Graham model. Through the new model, accurate information about double-layer capacitance, percolation capacitance, and bulk capacitance, which composes the electrode's capacitive performance, could be obtained. This work provided novel knowledge to develop PANI deposition and hence to achieve greater capacitances.Authors acknowledge to Presidency of the Turkish Republic Department of Strategy and Budget for the financial support Project Grant No. 2016K12-2841 and Scientific and Technical Research Council of Turkey (TuBTAK) for financial support of D Kiymaz in the frame of program 2218 with the Grant No. 1929b011800282.Presidency of the Turkish Republic Department of Strategy and Budget [2016K12-2841]; Scientific and Technical Research Council of Turkey (TuBTAK) [1929b011800282