A highly selective and sensitive near-IR optical sensor, benzoselenadiazole based diarylamine (TBS-HN), for fluoride (F(-)) has been designed and synthesized. TBS-HN also shows turn-on ratiometric fluorescence signaling in the presence of F(-) by inhibiting the excited state intramolecular proton transfer (ESIPT) processes.

Summary: Benzoyl peroxide is used as an oxidizing agent for the first time in the synthesis of conducting polypyrrole. Synthesis of polypyrrole is commonly performed by chemical oxidative polymerization using water‐soluble oxidizing agents. In this work, polypyrrole was prepared using organic solvent‐soluble benzoyl peroxide as an oxidizing agent in the presence of p‐toluenesulfonic acid (p‐TSA) and sodium lauryl sulfate (SLS) surfactant via the inverted‐emulsion‐polymerization technique. During polymerization, SLS is converted to dodecyl hydrogensulfate (DHS) and incorporated on to polypyrrole along with p‐TSA dopant, indicating SLS is acting as emulsifier as well as dopant. The influence of synthesis conditions such as the duration of the reaction, the temperature, the concentration of the reactants, etc., on the properties of polypyrrole was investigated to determine the optimum conditions for the synthesis of polypyrrole salt. Polypyrrole was obtained in a reaction time of 1 h with high yield (154 wt.‐% with respect to pyrrole used) and good conductivity (2 S · cm−1). The conductivity of polypyrrole‐salt was found to be nearly the same even after seven months of storage at ambient temperature (1.7 S · cm−1). magnified image

Two fullerene-terthiophene dyads without hexyl chains (3T-C₆₀) and with hexyl chains (3TH-C₆₀) on the terthiophene substituent are synthesized by 1,3-dipolar cycloaddition of corresponding azomethine ylides to C₆₀. The cyclic voltammetry studies indicate no apparent electronic communication between the terthiophene pendent group and the fulleropyrrolidine core in the ground state. However, a significant florescence quenching is observed for 3T-C₆₀ and 3TH-C₆₀, compared to their fluorescent terthiophene (3T) and 3TH precursors, respectively, suggesting the occurrence of strong intramolecular electron/energy transfers in the photoexcited state. Furthermore, these new fulleropyrrolidine derivatives are applied as electron acceptors to fabricate poly(3-hexylthiophene) (P3HT) based bulk heterojunction solar cells. The incident photon-to-current efficiency (IPCE) value of the P3HT/3T-C₆₀ device is significantly higher than that of the P3HT/PCBM cell in wavelengths of 350-420 nm. This finding provides direct evidence for the contribution of 3T excitons to the photocurrent. Replacing 3T-C₆₀ with 3TH-C₆₀ effectively improves the morphology of the photoactive layer and widens the window of optimal D/A ratios, raising the power conversion efficiency (PCE) from 2.14% to 2.54%. Importantly, these devices exhibit superior stability of PCE against high-temperature aging.

A tetra(aniline)-alkyl diblock compound was designed, synthesized and fully characterized. By employing suitable conditions, doped, electroactive microstructures could be prepared. The microstructures were characterized in detail and their anisotropic conductivity measured for the first time.

Copolymer containing new thermally reversible click chemistry‐assisted triazole‐substituted azobenzene and fulgimide units in the pendant F‐co‐A was prepared by free‐radical solution addition polymerization technique. The F and A were also prepared for comparison. The DSC analysis of F indicates that the polymer possessing the C‐form of fulgimide unit exhibited higher Tm than that of E‐form of the same polymer and revealed that the C‐form of fulgimide unit in F is highly ordered. The cis‐trans back isomerization behavior of the click chemistry‐assisted triazole‐substituted azobenzene unit in film A has thermal irreversibility, while in F‐co‐A it exhibited thermal reversibility. The UV‐exposed film of F‐co‐A heated around Tg leads to cis‐trans back isomerization of azobenzene unit and thermally stable C‐form of fulgimide which retains its conjugated structure where both the photochromic units are converted into planar conformations and exhibit high fluorescence properties. The fluorescence maxima of C‐form in F‐co‐A red shifted compared with F, because the substituted triazole ring in the azobenzene unit stabilized the C‐form of fulgimide unit. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7843–7860, 2008

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This paper proposes an improved model approach to single diode PV model by Hybrid Genetic Algorithm Particle Swarm Optimization (Hybrid GA-PSO) technique. The main objective is to extract accurate parameters of PV model for the simulator developers which could help them to develop an enhanced PV model in Matlab/Simulink environment. Specifications provided by the manufacturer's data sheet of PV module have been used for the computation of model parameters. Hybrid approach of GA and PSO is purposely chosen to utilize their effectiveness in these kinds of applications. This method is used to optimize the parameters Ipv, a, Rse and Rsh with their best optimal values. For the confirmation of accuracy and computational time of the proposed method, poly-crystalline PV module (KL070) has been selected and the best optimal value of each parameter has been obtained using Hybrid GA-PSO. Finally, the extracted values have been used in the single diode PV model and tested for various irradiations and temperatures. The proposed methodology results in marked improvement and can be a tool for simulator developers who require absolute and accurate model.

A Cu 2þ -specific colorimetric sensor of bis-triazole-appended azobenzene receptors I and II was designed and synthesized. Receptor II shows high selectivity toward Cu 2þ in acetonitrile/water (80:20, v/v) solution based on the internal charge transfer (ICT) mechanism. The tridentate coordination behavior was proposed with 1:1 stoichiometry between receptor II and Cu 2þ . Herein, the Cu 2þ gives rise to a large change in the absorption spectra (from red to pale yellow) that is clearly visible to the naked eye.