Siddik Icli

Ege University · Department of Chemistry

The effects of surface modification of titanium dioxide (TiO2) on the performance of inverted type organic solar cells (i-OSCs) was investigated in this study. A series of benzoic acid derivatized self-assembled monolayer (SAM) molecules of 4'-[(hexyloxy)phenyl]amino-3,5-biphenyl dicarboxylic acid (CT17) and 4'-[1-naphthyl (phenyl)amino]biphenyl-4-...

Two organic dyes for dye-sensitized solar cells (DSSC) based on spirobifluorene were synthesized and characterized. Electrochemical, spectroscopic and photovoltaic properties of the dyes have been investigated. Hexyloxy substituted triarylamine was used as electron donating moiety in the molecule while spirobifluorene and cyanoacrylic acid were use...

1,4,5,8-Naphthalenedianhydride is converted to N-(2-ethylhexyl)-1,4,5,8-naphthalenetetracarboxylic monoanhydride monoimide (2a) and N-(2-hydroxyethyl)-1,4,5,8-naphthalenetetracarboxylic monoanhydride monoimide (2c) through the potassium salt prepared from a reaction with potassium hydroxide. N-Dodecyl-1,4,5,8-naphthalenetetracarboxylic monoanhydrid...

A complete structural and vibrational analysis of the 4-(2,5-di-2-thienyl-1H-pyrrol-1-yl) benzoic acid (TPBA), was carried out by ab initio calculations, at the density functional theory (DFT) method. Molecular geometry, vibrational wavenumbers and gauge including atomic orbital (GIAO) (13)C NMR and (1)H NMR chemical shift values of (TPBA), in the...

A novel dinuclear type, highly conjugated ligand based ruthenium(II) polypyridyl complex of KO-20 synthesized in our laboratories, and constructed dye sensitized solar cell showed an overall conversion efficiency of η: 6.58 and IPCE: 65%. Extension of the conjugation and double ruthenium center improved the molar absorption coefficient ε = 35000 l...

The molecular structure and vibrations of 5-(diphenyl) amino] isophthalic acid (DPIFA) were investigated by different spectroscopic techniques (such as infrared and Raman). FT-IR, FT-Raman and dispersive Raman spectra were recorded in the solid phase. HOMO-LUMO analyses were performed. The theoretical calculations for the molecular structure and sp...

Singlet oxygen quantum yields (Φ Δ) of different perylene diimides (PDIs) containing phenyl (PDI-Ph), pyrene (PDI-Pyr), and indole (PDI-In) units in bay positions of the ring were determined using 1,3-diphenylisobenzofuran (DPBF) method in toluene/methanol (99:1) system. Pyrene-substituted PDI were the most efficient singlet oxygen generator among...

Two organic sensitizers with the structure donor-π-acceptor, having tri-arylamine as electron donor, cyano-acetic acid as electron acceptor and a phenyl or thiophene ring as π-bridge, are synthesized. The synthetic procedure, the photophysical and electrochemical properties of both dyes are described in detail. In particular, cyclic voltammetry and...

A new method for synthesis of titanium dioxide (TiO2)-dye nanoparticles is reported. TiO2 nanocrystals were obtained at 150 and 200 °C by using chemically bonded TiO2-sensitizer dye as a precursor. Titanium tetraisopropoxide was first modified with a dye molecule and then precipitated by dropping into acidic water. A strongly colored precipitate wa...

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 (1)H NMR. Cyclic Voltammetry analysis is performed to determine the energy levels of the perylene derivative. Optical characteristics were determined by visible absorption and fluorescence emiss...

Spectral-luminescent properties of the newly synthesized 2-(3′-coumarinyl)-5-(2′-(R-amino)-phenyl)-1,3,4-oxadiazoles has been investigated in solvents of various polarity and hydrogen-bonding ability. It has been found that for all the studied compounds no excited state intramolecular proton transfer occurs despite the presence of coumarinyl fragme...

In recent years, fuel cell systems have been popular as electricity production systems these are clean, environmental-friendly, modular, and independent from fossil fuels. In Pamukkale University Clean Energy House, Denizli–Turkey, 1.2 kWp hydrogen–fuel cell–DC micro grid system was set up to investigate the fuel cells with DC power distribution. I...

A perylene diimide (PDI) derivative was used as a dopant in the hole transport layer (HTL) of an organic light emitting device. The HTL examined was poly (N-vinylcarbazole) (PVK) and the PDI used was N,N′-di-dodecylperylene-3,4,9,10-bis-(dicarboximide), (N-DODEPER). The structure of the device was ITO/PEDOT:PSS (70nm)/PVK:N-DODEPER(0, 0.2, 0.4, 0.8...

We report here the synthesis of a novel branched quasi-dendric system, 9,9 0 -(9,9 0 -dihexylfluorene-2,7-diyl)bis[3,6-bis(2,5-bis(2-thienyl)pyrrol-1-yl)carbazole], (FCSNS), in four steps, followed by coating onto an ITO-coated glass surface by an electropolymerization process to give a very stable cross-linked polymeric film (poly-FCSNS). The yell...

In 1-arylhydantoins an o-methyl group is effectively larger than an o-chloro substituent in restricting rotation about the aryl-C—N bond, whereas in 3-arylhydantoins and 3-aryl-2-thiohydantoins the reverse order of sizes is observed. This difference is attributed to repulsion between the chlorine atom and a carbonyl oxygen atom in the torsional tra...

1H and 13C n.m.r. spectra have been determined for a number of 1- and 3-arylhydantoins in achiral and chiral solvents. These compounds, which have enantiomeric rotational isomers, show restricted internal rotation about the aryl C—N bond at normal probe temperatures. Chemical shifts between corresponding protons on the pairs of rotamers, induced by...

Photolysis of suitable oxalate esters leads to alkyl radicals which in the case of di- and tri-tert-butylmethyl abstract hydrogen and for triisopropylmethyl-d18 gives an esr spectrum consistent with the 'cogwheel' conformation for this species.

Polymer:quantum dot (QD) composites show enhanced optical and electronic properties. In this study, polymer light-emitting diodes (PLEDs) were fabricated and characterized using poly[2-methoxy-5-(2-ethyl-hexyloxy)-1,4-phenylenevinylene] end capped with polyhedral oligomeric silsesquioxanes (MEH-PPV-POSS) as a luminescent polymer host and copper ind...

Two new sensitizers for dye sensitized solar cells have been designed consisting of thiophene units asymmetrically functionalized by N-aryl carbazole. The di(tert-butyl) carbazole moieties acts as an electron donor group, the thiophene chain as a bridge group, and the cyanoacrylic acid as an anchoring and electron acceptor group. An increase of the...

1,8-Naphthalimide groups containing imidazolium iodide salts of different alkyl chain length on the imidazole group were synthesized. Hexafluorophosphate and bis(trifluoromethanesulfonyl)imide salts were obtained by ion exchange reactions. The synthesized salts were characterized using a variety of spectroscopic techniques. Fluorescence emission qu...

A novel photoresponsive organic field effect transistor (photOFET) based on naphthalene bis-benzimidazole (NBBI) by employing a transparent divinyltetramethyl disiloxane-bi (BCB) as dielectric is presented. The optical properties of naphthalene tetracarboxylic diimide (NTCDI) were changed by substitution of imidazole groups, in order to improve amp...

We report the synthesis, electrochemical and photovoltaic properties of triphenylamine based novel organic sensitizer, comprising donor, electron-conducting and anchoring group. Different triphenylamines were synthesized as donor unit and connected to cyano-acidic acid acceptor over vinyl group. In this work, we studied on two novel dyes (TPA2, TPA...

Efficient dye sensitizers N,N′-dialkylcarbazolocarbazole derivatives BG-501 and BG-502 were synthesized and characterized. UV–vis, 1H NMR and CV were used for the structural characterization. The aim of the synthesis of these molecules is to improve some optical and electronic properties such as molar absorption coefficient, spectral coverage and e...

The influence of molecular side groups on the electron backtransfer into ruthenium-dye molecules adsorbed on ultra-thin nanoporous TiO2 layers has been investigated by modulated surface photovoltage spectroscopy in argon atmosphere. All ruthenium-dye molecules contained one bipyridine (bpy) ligand with two carboxylic groups for anchoring at the TiO...

The novel ligand 1-(2,4,6-trimethylbenzyl)-2-(2′-pyridyl)benzimidazole and its heteroleptic ruthenium (II) complex were synthesized. The complex was characterized using spectroscopic methods and cyclic voltammetry. Charge-separation was investigated within nanoporous titanium dioxide employing surface photovoltage spectroscopy. The performance of t...

Hybrid solar cells have been fabricated using perylene monoimide–monoanhydride dyes with nanorod zinc oxide electrodes as electron transporting layers. We have investigated the influence of the spacer alkyl chain length of perylene monoimide–monoanhydride (PMIMA) dyes on the device performance in hybrid solar cells using nanorod zinc oxide electrod...

We report here electrochemical synthesis of novel soluble donor–acceptor (D–A) polymer with suitably functionalized perylenetetracarboxylic diimide dye derivative covalently linked to carbazole moiety (Cbz-PDI). The band gap, Eg was measured using UV–Vis spectroscopy and compared with that obtained by cyclic voltammetry (CV). Efficient intramolecul...

4,4′-Di(N-carbazoyl)biphenyl monomer (CBP) was synthesized and coated onto ITO–glass surface by electrochemical oxidative polymerization. Its CV shows two distinct one-electron and stepwise oxidation processes occurred at 1.29 and 1.61 V. By using this property, the monomer was electrochemically polymerized separately at these oxidation states and...

We report here the synthesis of a new electroactive monomer 3,6-di-tert-butyl-[4-(2,5-di-2-thienyl-1H-pyrrol-1-yl)phenyl]-9H-carbazole in five steps and polymerization of this monomer by two different procceses: Kumada Coupling and electro-oxidative. The product obtained by chemical polymerization exhibits a high thermal stability and narrow molecu...

New dicationic bis-imidazolium salts based ionic liquids were synthesized to develop new electrolytes to improve photovoltaic properties of dye sensitized solar cells. Various properties of electrolytes such as viscosities, ion diffusion coefficients, charge transfer resistances and photovoltaic properties were studied. Electrochemical impedance sp...

Sahara desert sand (SaDeS) was employed as a mineral sorbent for retaining organic dyes from aqueous solutions. Natural sand has demonstrated a strong affinity for organic dyes but significantly lost its adsorption capacity when it was washed with water. Therefore, characterization of both natural and water washed sand was performed by XRD, BET, SE...

Conventional and microwave-assisted synthesis of ZnO nanorods have been performed with and without using PEG400. ZnO nanorods were synthesized with 50-250 nm of diameter which depends on the used surfactant and methods. Surfactant effects of PEG400 on the size and morphology of ZnO nanorods were investigated. The microwave method was compared to th...

We report optical and electrochemical properties of polyether derivatives of perylenediimides (PDIs) thin films formed in various materials (semiconductor, insulator, amorphous and self-assembly). Perylenediimides adsorbed on nanocrystalline TiO2 (NT) nanocrystalline alumina (NA), amorphous silicon (PS) and neat self-assemblied (SA) films were prep...

The charge transport and transient absorption properties of K27 dye-sensitized solar cell have been investigated. The current–voltage (I–V) characteristics of the solar cell were analyzed by the thermionic emission theory. The ideality factor, barrier height and series resistance values of the solar cell were determined. The ideality factor higher...

A novel distyryl-substituted boradiazaindacene (BODIPY) dye displays interesting properties as a sensitizer in DSSC systems, opening the way to further exploration of structure-efficiency correlation within this class of dyes.

In this study, donor-acceptor type thiophene-perylene-thiophene monomers were synthesized and polymerized by both oxidative polymerization using FeCl3 as catalyst and the electrochemical process. UV–vis, FTIR, 1H NMR, and elemental analysis techniques were used for structural characterization. Thermal behaviors of these compounds were determined by...

New [Ru(L1)(dcbpy)(NCS)2] complex was synthesized in a one-pot reaction starting from [RuCl2(p-cymene)]2, where the ligands (dcbpy=4,4'-dicarboxy-2,2'-bipyridine, L1=dipyrido[3,2-a:2',3'-c]phenazine-11-ylcarbonyl)-sodium) are introduced sequentially. The resulting complex was characterized by IR, NMR, and elemental analysis. The complex was labeled...

An amphiphilic swallow-tail bipyridyl ligand, 4,4′-bis(dihexylmethyl)-2,2′-bipyridine, and its heteroleptic ruthenium (II) complex were synthesized starting from dichloro-(p-cymene)ruthenium (II) dimer. The complex was characterized by UV/Vis and FTIR spectrophotometers, NMR spectroscopy and cyclic voltammetry. The performance of this complex as ch...

We have fabricated a bilayer heterojunction solar cell consisting of p–n active layers of naphthalenetetracarboxylic bis-benzimidazole, N-CON, and zinc phthalocyanine, ZnPc. Conjugated naphthalene derivative of naphthalene bis-benzimidazole was employed as an electron acceptor. Bilayer solar cells were produced by successive evaporation of zinc pht...

New kind of azo chromophores containing thiophene moiety and salicyaldimine-based ligand as side chains have been synthesized by a sequential process for optical sensing of Cu2+ metal ions in organic solution. Compounds have been characterized by IR and UV–vis spectrophotometer, 1H NMR, 13C NMR, MS, TGA and CV instruments. Spectral characteristics...

New [Ru(L1)(H2dcbpy)(NCS)2] [K30] and [Ru(L2)(H2dcbpy)(NCS)2] [K27] complexes were synthesized in a one-pot reaction starting from [RuCl2(p-cymene)]2, where the ligands (H2dcbpy = 4,4′-dicarboxy-2,2′-bipyridine, L1 = 4,5-diazafluoren-9-one, and L2 = 1,10-phenanthroline-5,6-dione) are introduced sequentially. The resulting complexes were characteriz...

Perylene diimide denvatives are one of the G-quadruplex DNA interactive agents which are thought to be useful in application of cancer treatment Starting from this consideration, N-(2,6-diisopropylphenyl)-N’-(4-pyridyl)-perylene-3,4,9,10-tetracarboxy ??lic diimide (PYPER) was synthesized, radioiodinated with 131I, and its radiopharmaceutical potent...

We report the characterization of 1,8-naphthalene benzimidazole comprising carboxyl group. We have fabricated dye-sensitized nanocrystalline TiO{2} solar cell (DSSC) based on naphthalene benzimidazole dye. The device structure is FTO/nc-TiO{2}/Dye/I-/ I{3}-/Pt/ FTO. We calculated the EHOMO and ELUMO levels of this new dye by using cyclic voltammetr...

We have studied the influence of the spacer alkyl chain length of perylenemonoimide (PMI) dyes on the device performance in dye-sensitized solar cells (DSSCs). We observed that the dyes with longer and brunched alkyl chains exhibit higher efficiencies in DSSCs. In line with these statements we now report the highest efficiency obtained under standa...

Electrochemistry of perylene imide and anhydride derivatives adsorbed on semiconductor TiO{2} (NT) and insulator Al{2}O{3} (NA) metal oxide films were presented. Adsorption rates on metal oxide surface are observed to be strongly depending on molecular structure. Monoanhydride-monoimide derivatives show two reversible reductions in solution and one...

A 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, ¹H NMR, ¹³C NMR, MS,...

Solution-processed n-type organic field-effect transistors (OFETs) have been fabricated using soluble derivatives of perylene diimide and naphthalene diimide. We report the synthesis of the organic semiconductors and the fabrication of bottom gate OFET devices using solution-processed organic dielectrics. Surface morphology studies reveal films wit...

We have fabricated heterojunction solar cells comprising active layers of perylene diimide (PDI) or perylene bisbenzimidazole (CONPER, conjugated perylene dye) as electron acceptor and ZnPC as donor. Bilayer solar cells were produced by successive evaporation of zinc phthalocyanine (ZnPC) and perylene diimide (PDI) or perylene bisbenzimidazole (CON...

The degradation of gallic acid and imidacloprid with supported Millennium PC500 and Degussa P25 TiO2 is reported. TiO2 particles were immobilized using a titanium sol-solution and direct deposition on glass supports. The film characterization was done by x-ray diffraction, scanning electron microscopy, and atomic force microscopy, and degradation o...

A new water-soluble perylene diimide derivative, N,N′-bis(12-sulfoaminododecyl)-3,4,9,10-perylenetetracarboxdiimide (SULFAPER), has been synthesized and characterized by visible, fluorescence, IR, 1H and 13C NMR, mass, CV and time resolved measurements. Its photophysical properties in aqueous and organic solutions have been described. The singlet e...

A dielectric anisotropy property of a TEGDC (tetraethylene glycol-bis(3-methylimidazolium) dichloride) is investigated as a function of frequency. TEGDC showed an extremely large negative dielectric anisotropy (-10.95 to -4753.73). Variation of dielectric anisotropy (delta epsilon) with respect to the spot frequencies reveals that liquid crystal (L...

Thermal stabilities, solubilities redox potentials and photophysical parameters of 10 synthesized N-alkyl(aryl) derivatives of naphthalene diimides were studied for selecting the best derivatives at concentrated sun light experiments. N-aryl substitutions created better thermal stabilities than the N-alkyl substitution in naphthalene diimides. LUMO...

We have fabricated solid-state, dye-sensitized nanocrystalline TiO2 solar cells (DSSC) based on perylene derivative dye, N,N′-bis-2-(1-hydoxy-4-methylpentyl)-3,4,9,10-perylene bis (dicarboximide) (HMPER) with two different polythiophenes as hole conductors; i.e. poly (3-octyl thiophene) (P3OT) and poly (3-hexyl thiophene) (P3HT), respectively. HMPE...

Magnetic non-equivalence of diastereotopically related proton and 13C nuclei in enantiomeric and diastereomeric rotational isomers of 3-aryl-5-alkyl-2,4-oxazolidinedlones has been investigated. Steric interactions between the aryl and the heterocyclic moieties of these compounds produce sufficient restriction to rotation about the aryl CN bond that...

The singlet oxygen quantum yields (ϕΔ), LUMO energy levels (eV), photo stabilities under Xe-lamp irradiation of N,N′-di-dodecyl-3,4,9,10-bis(dicarboximide)perylene and N,N′-di-(1-dehydroabiethyl)-3,4,9,10-bis(dicarboximide)perylene, N-DODEPER and ABIPER, respectively, in different host matrices (solution, PVC and sol–gel matrix) are determined. Que...

UV/VIS spectral characteristics of three new biologically active natural products, isolated from Turkish lichens, have been investigated in solvents of various polarity and proton donating ability. The effect of the solvent on spectral characteristics has been estimated. Quantum chemical calculations with the optimization of molecular geometry were...

This photocatalytic method was aimed to destroy bacteria, to prevent fungi in some industrial products and to create desirable hygienic medium under solar irradiation. The efficiencies of disinfection with the photoactive metal oxides and the Sahara desert dust was investigated. We have studied photocatalytic disinfection of two-groups of microorga...

Photophysical properties of menadione sodium bisulfite (MSB), menadione nicotinamide bisulfite (MNB) and menadione dimethylpyrimidinol bisulfite (MPB) were studied in their aqueous solutions. They are oil-soluble vitamins and not naturally fluorescent, however, it is possible to gain fluorescent signal by the use of phosphate buffer solutions conta...

In this study, the photophysical characteristics, like molar extinction coefficients, Stoke's shifts, quantum yields, radiative and fluorescence lifetimes, fluorescence rate constants, radiationless deactivation rate constants, and singlet energies of the fluorescent mesomorphic diketopyrrolopyrrole derivatives, (DPPDs), 3,6-bis(4-octyloxyphenyl)-2...

The spectral-fluorescent properties of substituted 2- and 4-(N-arylimino)quinolines have been investigated in solvents of different polarity and proton donating ability, and in immobilized phases of PVC films and sol–gel matrix. The effect of the solvent on spectral characteristics has been estimated. It has been shown that, despite the possibility...

The spectral-luminescent properties and electrochemistry of the N,N′-bis-n-butyl derivative of naphthalene diimide were studied. The main photophysical parameters (quantum yield, rate constants of fluorescence and of non-radiative deactivation and fluorescence lifetime) were determined. The LUMO value (-3.51 eV) was determined by cyclic voltammetry...

The spectral characteristics of camptothecin have been investigated in solvents of various polarity and proton donating ability. The effect of the solvent on the spectral characteristics and the dipole moment in the excited state have been estimated. Different theoretical approaches have been compared in order to estimate the excited-state dipole m...

The photophysical and photochemical properties of an azlactone derivative, 4-(p-N,N-dimethylaminophenylmethylene)-2-phenyl-5-oxazolone, (DPO) in a sol-gel matrix have been examined. The fluorescence quantum yield, radiative lifetime, fluorescence lifetime, fluorescence rate constant and singlet energy values of the DPO dye were determined in a modi...

Three natural products were isolated from three dierent Turkish lichens. Microbiological investiga- tions were also examined of these lichens. Compound 1 is known as 2-hydroxy-4-methoxy-3,6-dimethyl benzoic acid, and is isolated from Pseudevernia furfuracea for the rst time. Compounds 2 and 3 are de- tected as new compounds and called, 3-acetyl-4-a...

The photochemical aromatic substitution reactions described within this article are mainly devoted to homocyclic aromatic compounds. The work described is focused on the mechanism of the various reactions described. An outstanding mechanistic feature of photochemical aromatic substitution is that, in contrast to thermal reactions, photochemical sub...

4-Methyl-8-hydroxy-benzo(6,7)coumarin, I, 4-methyl-6-hydroxy-benzo(5,6)coumarin, II, and 2-methyl-6-hydroxy-benzo(5,6)chromone, III, have shown similar absorption and fluorescence emission spectra. Fluorescence emission quantum yields for I and III are found to be very low, φf=0.02, but 4-methyl-6-hydroxy-benzo(5,6)coumarin, II, has a eight-fold hi...

Rose oxide was photosynthesized in aerated acetonitrile solutions from citronellol via aromatic diimide (dehydroabietyl perylene diimide and n-butyl naphthalene diimide (BUNAP)) singlet photosensitizers under sodium light (0.2–0.4 sun) and concentrated sun light (90–100 sun). The yield of formation of rose oxide is high by concentrated sun light, w...

The decrease of fluorescence emission of phenol was studied in the presence of photoactive oxides (TiO 2 , ZnO and Fe 2 O 3) irradiated with a sodium lamp, direct sunlight (1 sun) and concentrated sunlight (40–50 suns) in aqueous solutions. As expected photodegradation of phenol was seen to be faster for all of the oxides irradiated by concentrated...

Azlactone molecules can be protonated in acidic media, and the process of protonation is irreversible due to ring opening in solutions. A new fully reversible pH sensor has been developed 4-(p-N,N-dimethylamino phenyl methylene)-2-phenyl-5-oxazolone (DPO), an azlactone derivative, embedded in a plasticized PVC polymer film. The sensor membrane is c...

The absorbance maximum of synthesized water soluble perylene 4-carboxylphenyl-bis-diimide (PECA) is found to be about 50 nm lower in water, as compared to absorbance in organic solvents, and the singlet energy is 61.4 kcal mol−1 in aqueous solutions, compared to 54.4 kcal mol−1 in organic solvents. The fluorescence quantum yields were similar in bo...

Seven derivatives of naphthalene diimides, synthesized, have shown similar photophysical properties. Low fluorescence quantum yields (0.002–0.006) and short fluorescence lifetimes (5–18 ps) have suggested rapid intersystem crossing processes from excited singlet state. Quenching of fluorescence emissions of aromatic donor molecules, i.e. naphthalen...

The synthesis of perylene-3,4,9,10-tetracarboxylic acid-bis(N,N′-dodecyl-polyimide) (poly PTDI) and polyamic acid has been achieved from perylene dianhydride and dodecylamine. It was found that this new polyimide has very high thermal photostability. Poly PTDI decomposes at 475°C and shows weak fluorescence compared with the monomer PTDI possibly d...

Experimental and theoretical evaluations have proven that very low fluorescence quantum yields of azlactones in solution are not caused by an efficient inter system crossing from S1*(ππ) to T*(nπ) states, but rather from solvation and steric effects, that result in non-planarity of the molecular system. High fluorescence quantum yields in the solid...

N,N'-Di-(-1-Dehydroabietyl) perylene-3,4,9,10-bis(dicarboximide) is prepared in 95% yield by the condensation of perylene 3,4,9,10-tetracarboxylic dianhydride with dehydroabietyl amine. Thermal and photostable bright red-orange dye is measured to have a fluorescence quantum yield of unity, Qf=1, in chloroform solutions. Solubility of the dye is 1.8...

Singlet energies and fluorescence quantum yields of synthesized dihydrocarbazolocarbazole, 1, dimethylcarbazolocarbazole, 2, dibenzylcarbazolocarbazole, 3, were measured to be between 76.5−74.3kcal/mol and 0.07−0.02, respectively. A Stern-Volmer plot of fluorescence quenching of dihydrocarbazolocarbazole, 1, with 2,4,5,7-tetranitrofluorenone, 4, ha...

The synthesis of perylene-3,4,9,10-tetracarboxylic acid-bis(N,N′-dodecyl-polyimide) (poly PTDI) and polyamic acid has been achieved from perylene dianhydride and dodecylamine. It was found that this new polyimide has very high thermal photostability. Poly PTDI decomposes at 475°C and shows weak fluorescence compared with the monomer PTDI possibly d...

Virgatic acid triterpene, extracted from salvia plants, is found to be quenched by singlet oxygen at chemical and photosensitized oxygenations. A charge-transfer energy transfer is attributed to the quenching of singlet oxygen, which may be accounted as a protective mechanism of salvia plants to photooxygenations.

Abstract: Perylene bis-n-dodecyl diimide is found to quench fluorescenc emissions of naphthalene, phenanthrene and dihydrocarbazolocarbazole molecules at rates of 4.4 x 10(11), 2.8 x 10(12) and 2.5 x 10(4) M-1 sec(-1), in respective order of aromaticity. These unusulally high rates of fluorecence quenchings are attributed to Perrin model static que...

The synthesis of a chloroform soluble perylene 3, 4, 9, 10-tetracarboxylic acid-bis-N, N′-dodecyl diimide via condensation of perylene 3, 4, 9, 10-tetracarboxylic dianhydnde and 1, 12-diamino dodecane is described. The thermal analysis is shown thermal stabilities above 400°C. Thermal and photostable dye is measured to have a fluorescence quantum y...

4-Methyl-3-phenyl-2-thiazolidinethione was reacted with both photochemically and chemically generated singlet oxygen. Despite reaction conditions which were selected to favor oxidation of the sulfide group, both reactions afforded a single product arising solely from thiocarbonyl oxidation.

A supramolecular structure, perylene 3,4,9,10-tetracarboxylic acid-bis-N, N'-p-aminophenyl diimide, has high thermal and photo stabilities, detected at DSC, TGA, and emission spectroscopy studies. The low fluorescence quantum yield of 0.20, indicates the application possibilities on photo electron transfer reactions.

Absorption and fluorescence wavelengths for a series of a lactones have been measured from acetonitrile solutions that had no pre-light exposure. Fluorescence quantum yields, Qp are found to be in general less than 0.01, excluding the the derivatives with naphthyl and p-dimethylaminophenyl substituents. Previously reported QF values did not not fit...

Abietic acid, which is the terpene acid component of natural colophony, was irradiated at above 300 nm in the presence of benzophenone and a colloidal platinum catalyst. The expected product of dehydroabietic acid was formed to the extent of 81 %, hydrogen generation occurred to a negligibly small amount. The hydrogen generation, even as a by-produ...

The synthesized perylenes 3,4,9,10-tetracarboxylic acid N,N′-ethyl, phenyl, ρ-anisyl, α-naphthyl and acetyl diimides have shown great variations in absorption and emission spectra. The variation in molar extinction coefficients and fluorescence quantum yields have indicated that steric and electronic effects, caused by N-substitution, alters emissi...

Sterically hindered N-(o-tolyl) and N-(o-chlorophenyl) substituted 2-thioxo-4-oxazolidinones 1 and-thiazolidinones (rhodanines) 2 forming enantiomers by partial rotation around the C-N bond are synthesized. Their chirality is proven by the presence of diastereotopic protons (or carbon atoms) detected by H-1 or C-13 NMR (1c, 2c). In the presence of...

In situ radiolysis of hydroxypyridones in aqueous solution produces several radicals detected by ESR. These are produced by primary and secondary reactions of hydroxyl radicals. Azaquinoidal structures were detected from 3- and 5-hydroxypyridones.

In order to clarify the reaction mechanism, to investigate transformation reactions and to determine the selectivities of the oxidizing radicals, the title reactions are investigated and the rate constants determined.