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Li-, Na-, K-, Rb- and Cs-montmorillonites were saturated with benzidine, these organo-clay complexes heated under vacuum to 200°C and IR spectra recorded at various temperatures. Benzidine is mostly bound to interlayer cations through water molecules, except in Cs-clay where bonding to hydrophobic water and to water molecules which are hydrogen bonded to the oxygen plane predominates. During the thermal treatment water is lost and alkali, cations coordinate directly with benzidine. In Cs-, and to some extent also in Rb- and K-montmorillonite, benzidine is oxidized to semiquinone and quinoidal cation during the thermal treatment. 相似文献
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Ravindra Kumar Gupta Suraj Kumar Pathak Balaram Pradhan Monika Gupta Santanu Kumar Pal Prof. Achalkumar Ammathnadu Sudhakar 《Chemphyschem》2016,17(6):859-872
Selenium‐annulated perylene tetraesters that stabilize the hexagonal columnar phase have been synthesized and characterized, and their thermal and photophysical behavior has been determined. The mesophase range decreased with an increase in chain length. A comparative account of the structure–property relationships of this series of compounds with respect to parent perylene tetraesters, N‐ and S‐annulated perylene tetraesters, in terms of their thermal, photophysical and electrochemical behavior is provided. The bay‐annulation of perylene tetraesters is a good option to modify the thermal and photophysical properties of perylene derivatives and it can provide a new avenue for the synthesis of several technologically important self‐assembling perylene derivatives. 相似文献
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[STRUCTURE: SEE TEXT] 1,6,7,12-Tetrabromoperylene-3,4,9,10-tetracarboxylic acid bisanhydride and the corresponding tetrabrominated perylene bisimide were first synthesized with high yields. The Suzuki coupling reaction of novel tetrabromoperylene bisimide with phenylbonoric acid was studied. The four bromines in the bay position of the perylene core were substituted successfully to yield 1,6,7,12-teraphenylperylene bisimide. The photochemical properties of the novel perylene bisimides were studied and presented. 相似文献
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Hoeben FJ Zhang J Lee CC Pouderoijen MJ Wolffs M Würthner F Schenning AP Meijer EW De Feyter S 《Chemistry (Weinheim an der Bergstrasse, Germany)》2008,14(28):8579-8589
A melamine derivative has been covalently equipped with two oligo(para-phenylenevinylene) (OPV) chromophores. This procedure yields a bifunctional molecule with two hydrogen-bonding arrays available for complementary binding to perylene bisimide derivatives. Depending on the solvent, hydrogen-bonded trimers, tetramers, and dimers on a graphite surface are observed for pure OPV-melamine by using scanning tunneling microscopy (STM). Upon the addition of perylene bisimide, linear tapes of perylene bisimide, 12-membered rosettes that consist of alternating hydrogen-bonded OPV-melamine and perylene bisimide moieties are visualized. These results provide direct evidence for the possible modes of hydrogen bonding within a supramolecular co-assembly in solution. Subsequently, the optical properties of pure OPV-melamine and co-assemblies with a perylene bisimide derivative were characterized in solution. In an apolar solvent, OPV-melamine self-assembles into chiral superstructures. Disassembly into molecularly dissolved species is reversibly controlled by concentration and temperature. Complementary hydrogen bonding to a perylene bisimide derivative in an apolar solvent yields multicomponent, pi-stacked dye assemblies of enhanced stability that are characterized by fluorescence quenching of the constituent chromophores. Titration experiments reveal that a mixture of hydrogen-bonded oligomers is present in solution, rather than a single discrete assembly. The solution experiments are consistent with the STM results, which revealed various supramolecular assemblies. Our system is likely not to be optimally programmed to obtain a discrete co-assembled structure in quantitative yield. 相似文献
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探讨了苝分子低聚体的形成条件和影响因素,这些低聚体与晶核形成紧密相关.用荧光光谱和吸收光谱法研究了不同的水含量和苝浓度对聚集的影响,低聚体属于具有光活性的J型,能发红光.计算得到低聚体的聚集数为9,平衡常数数量级较大. 相似文献
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A. Bermejo Martín-Lázaro J. Hernández García J. J. Santana Rodríguez 《Fresenius' Journal of Analytical Chemistry》1992,343(6):509-512
Summary Perylene and benzo[g,h,i]perylene have been studied in the presence of several surfactants. A synchronous spectrofluorimetric method has been developed for simultaneous determination of perylene and benzo[g,h,i]perylene in a hexadecyltrimethylammonium bromide (HDTAB) micellar medium, with detection limits of 0.12 and 0.21 ng/ml for perylene and benzo[g,h,i]perylene, respectively. The method has been applied to the determination of both hydrocarbons added to sea water with acceptable results. 相似文献
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Chenming Xue 《Tetrahedron letters》2009,50(8):853-15980
A soluble perylene monoanhydride diester has been designed and synthesized. It was successfully utilized as an efficient intermediate for the synthesis of the first unsymmetric perylene tetracarboxylic tetraester and a series of unsymmetric perylene diester monoimides in good to excellent yields. Its application in synthesis of unsymmetric perylene diimides was also demonstrated. Availability of such a versatile intermediate would enable the convenient integration of perylene tetracarboxylic tetraesters and perylene biester monoimides into intricate functional molecular systems. 相似文献
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合成了一种18-冠-6修饰的苝酰亚胺衍生物(1), 研究了其作为主体对金属离子与阴离子的选择性识别行为. 结果表明, 主体1对Ba2+离子具有一定的选择性响应, 并可以通过Ba2+调控主体1的堆积行为; 主体1还对F-离子有选择性响应, F-与苝酰亚胺单元之间发生了阴离子-π相互作用. 相似文献
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Most known perylene diimides are lipophilic, with few exceptions of hydrophilic derivatives. Even in the latter case, the compounds have limited water solubility and show a strong tendency to self-aggregation. In this paper we present the synthesis of four new perylene derivatives with three and four basic side chains, obtained by functionalizing the bay-area of perylene. These molecules show great solubility in aqueous media as hydrochlorides and their tendency to self-aggregate is remarkably reduced with respect to the previously synthesized two-chained perylene diimides. Their different spectroscopic properties in various solvents and conditions are reported and discussed. 相似文献
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Benzidine is an aromatic base of importance in industry. It represents a serious pollutant in many industrial effluents and its photodegradation is of great interest. The mechanism of photo-chemical decomposition of benzidine in different halomethane solvents in addition to the corresponding UV absorption spectra and fluorescence emission spectra are discussed. The photochemical quantum yields (phiC lambda ex = 254 nm) of benzidine in halomethanes is dependent upon the halogen content in the solvent. This effect may be explained by the assumption that free radicals are formed during photolysis of these solvents followed by the abstraction of electrons from a benzidine molecule forming macroradicals of the latter. Both mono- and di-radical benzidine cations have been detected by different techniques. The well known electron absorption peak at 283 nm is characteristic of neutral benzidine while those observed at ca. 370 and 565 nm are assigned to the blue-monoradical cation and yellow-diradical cation, respectively. The blue-monoradical cation has been isolated after irradiation as a blue precipitate. A comparison between neutral benzidine and the blue monoradical cation are made using both IR and differential thermal analysis (DTA) techniques. The fluorescence quenching of solutions of benzidine in inert solvents using halomethanes have been studied. The results obtained are interpreted in terms of a diffusional quenching mechanism. 相似文献
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Dr. Yongjun Li Zhihong Qing Yanwen Yu Taifeng Liu Runsheng Jiang Prof. Yuliang Li 《化学:亚洲杂志》2012,7(8):1934-1939
The synthesis of 1,10‐dihydroxyperylene bisimides by nucleophilic substitution of brominated perylene bisimide is described. 1,10‐Dihydroxyperylene bisimides formed J aggregates in nonpolar solvents and showed a clearly redshifted absorption band. The solvent polarity also influenced the hydrogen bond with the hydroxyl group, and thus, the photophysical properties of perylene bisimide. The photophysical properties of these dihydroxyperylene perylene bisimides can also be tuned by changing charge transfer from the hydroxyl groups to the perylene core through the introduction of metal ions. 相似文献
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A series of perylene and naphthalene diimide‐containing random copolyurethanes with different ratios of perylene/naphthalene diimide content was synthesized and characterized. Copolymerization improved the solubility of these rigid aromatic diimides, and the copolymers were soluble in common organic solvents like chloroform, tetrahydrofuran, and so forth. The absorption spectra of perylene‐based copolymers showed a red‐shifted peak at a wavelength of 557 nm corresponding to J‐type aggregates. For naphthalene copolymers, the quenching of fluorescence at higher naphthalene incorporation suggested the presence of aggregates because of the extensive π‐π stacking of the aromatic core. FTIR spectroscopic analysis showed that the hydrogen bonding tendency of the polymer decreased with increase in perylene/naphthalene incorporation. The fluorescence spectra of the perylene polymers were exactly a mirror image of the absorption spectra. The fluorescence spectra of the naphthalene polymers at higher naphthalene incorporation showed a red‐shifted excimer like emission peak, which was assigned as static excimers based on their excitation spectra. These polymers could exhibit two types of secondary interaction modes, namely, hydrogen bonding (via urethane linkage) and π‐stacking (via aromatic perylene or naphthalene units) thus highlighting the importance of polymer design in inducing self‐organization at both low and high incorporation of the rigid bisimide moieties. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 1224–1235, 2009 相似文献
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Hippius C Schlosser F Vysotsky MO Böhmer V Würthner F 《Journal of the American Chemical Society》2006,128(12):3870-3871
The synthesis of multichromophoric perylene bisimide-calix[4]arene arrays with up to five perylene units (containing orange, violet, and green perylene bisimide chromophores) and of monochromophoric model compounds was achieved by subsequent imidization of mono-Boc functionalized calix[4]arene linkers with three different types of perylene bisimide dye units. The optical properties of all compounds were studied with UV/vis absorption and steady state and time-resolved fluorescence spectroscopy. Upon excitation of the inner orange dye at 490 nm of array 3, strong fluorescence emission of the outer green perylene bisimide (PBI) chromophore at 744 nm is observed. The fluorescence excitation spectra of compounds 3 and 4 (lambdadet = 850 nm) show all absorption bands of the parent chromophores (e.g., all perylene units contribute to the emission from S1 state of the green PBI). Thus, the fluorescence emission and excitation spectra as well as time-resolved data of fluorescence lifetimes in the absence (tauD = 5.1 ns) and in the presence of an acceptor (tauDA = 0.8 ns) suggest efficient energy transfer processes between the perylene bisimide dye units. For the bichromophoric array 4, the energy transfer rate is calculated to a value of 1.05 x 109 s-1. These results demonstrate highly efficient energy transfer in cofacially assembled dye arrays. 相似文献
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You CC Hippius C Grüne M Würthner F 《Chemistry (Weinheim an der Bergstrasse, Germany)》2006,12(28):7510-7519
The fluorescent dye 4-dimethylamino-1,8-naphthalimide was incorporated at the bay area of N,N'-bispyridyl perylene bisimide to afford a fourfold-functionalized perylene bisimide ligand. Through self-assembly directed by metal-ion coordination, a multichromophore supramolecular entity composed of sixteen dimethylaminonaphthalimide antennas and a perylene bisimide-walled square core was subsequently constructed from this linear ditopic ligand and 90 degrees metal corner [Pd(dppp)](OTf)2 (dppp=1,3-bis(diphenylphosphino)propane; OTf=trifluoromethanesulfonate) in good yield. The isolated metallosupramolecular square was characterized by elemental analysis and 1H, 13C, and 31P{1H} NMR and UV/Vis spectroscopy. Furthermore, by means of 1H NMR diffusion-ordered spectroscopy (DOSY) the dimension of this assembly was evaluated by employing a previously reported perylene bisimide ligand and its square assembly as references. The results obtained confirm the square framework of the current assembly. The optical properties of this multichromophore dye assembly were investigated by UV/Vis and steady-state and time-resolved fluorescence spectroscopy. It was revealed that light captured by dimethylaminonaphthalimide antennas could be efficiently transported to the perylene bisimide core by a fluorescence resonance mechanism (energy-transfer efficiency E=95%), and this resulted in almost exclusive detection of intense perylene bisimide emission, irrespective of the excitation wavelength applied. The present square scaffold containing aminonaphthalimide antenna dyes exhibits more than seven times higher fluorescence quantum yield (Phifl=0.37) than a previously reported pyrene-bearing perylene bisimide-walled square (Phifl=0.05). Thus, this multichromophore square assembly with aminonaphthalimide antenna dyes is an artificial model for the cyclic light-harvesting complexes in purple bacteria. 相似文献
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Using scanning tunneling microscopy (STM) together with density functional theory (DFT) the growth behavior of perylene on the Cu(100) substrate has been investigated. As revealed by STM images, perylene molecules prefer to adopt lying configuration with their molecular plane parallel to the substrate, and two symmetrically equivalent ordered domains were observed. DFT calculations show that perylene molecule prefers to adsorb on the top site of substrate Cu atoms with its long molecular axis aligning along the [011] or [01-1] azimuth of the substrate which is the most stable adsorption geometry according to its highest binding energy. Consequently, two adsorption structures of c(8×4) and c(8×6), each containing two perylene molecules per unit cell, are proposed based on our STM images. The growth mechanism for ordered perylene domains on Cu(100) can be attributed to the balance between weak adsorbate-adsorbate interaction and comparable adsorbate-substrate interaction. 相似文献