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941.
Sandip V. KamatJ.B. Yadav Vijaya PuriR.K. Puri O.S. Joo 《Applied Surface Science》2011,258(1):482-488
Poly (3-methyl thiophene) thin films were prepared by chemical bath deposition technique on glass substrate; the prepared thin films were characterized for structural, morphological and optical properties. The variation in the oxidant concentration has an influence on the properties of the P3MeT thin films. The increase in the oxidant concentration leads to increase in the thickness of the film. The binding energy increases due to increase in oxidation concentration. The P3MeT thin films show smooth surface morphology with increase in oxidant concentration whereas the contact angle of the thin film decreases with increase in oxidant concentration. The optical absorbance of these thin films was found to increase with decrease in the optical band gap due to increase in oxidant concentration. 相似文献
942.
Ravi Yadav Thomas Simler Bhupendra Goswami Christoph Schoo Ralf Kppe Subhayan Dey Peter W. Roesky 《Angewandte Chemie (International ed. in English)》2020,59(24):9443-9447
A route to directly access mixed Al–Fe polyphosphide complexes was developed. The reactivity of pentaphosphaferrocene, [Cp*Fe(η5‐P5)] (Cp*=C5Me5), with two different low‐valent aluminum compounds was investigated. The steric and electronic environment around the [AlI] centre are found to be crucial for the formation of the resulting Al–Fe polyphosphides. Reaction with the sterically demanding [Dipp‐BDIAlI] (Dipp‐BDI={[2,6‐iPr2C6H3NCMe]2CH}?) resulted in the first Al‐based neutral triple‐decker type polyphosphide complex. For [(Cp*AlI)4], an unprecedented regioselective insertion of three [Cp*AlIII]2+ moieties into two adjacent P?P bonds of the cyclo‐P5 ring of [Cp*Fe(η5‐P5)] was observed. The regioselectivity of the insertion reaction could be rationalized by isolating an analogue of the reaction intermediate stabilized by a strong σ‐donor carbene. 相似文献
943.
Hee‐Jeong Cha Se‐Yeun Hwang Da‐Som Lee Akula Ravi Kumar Yong‐Uk Kwon Moritz Voß Eva Schuiten Uwe T. Bornscheuer Frank Hollmann Deok‐Kun Oh Jin‐Byung Park 《Angewandte Chemie (International ed. in English)》2020,59(18):7024-7028
Long‐chain aliphatic amines such as (S,Z)‐heptadec‐9‐en‐7‐amine and 9‐aminoheptadecane were synthesized from ricinoleic acid and oleic acid, respectively, by whole‐cell cascade reactions using the combination of an alcohol dehydrogenase (ADH) from Micrococcus luteus, an engineered amine transaminase from Vibrio fluvialis (Vf‐ATA), and a photoactivated decarboxylase from Chlorella variabilis NC64A (Cv‐FAP) in a one‐pot process. In addition, long chain aliphatic esters such as 10‐(heptanoyloxy)dec‐8‐ene and octylnonanoate were prepared from ricinoleic acid and oleic acid, respectively, by using the combination of the ADH, a Baeyer–Villiger monooxygenase variant from Pseudomonas putida KT2440, and the Cv‐FAP. The target compounds were produced at rates of up to 37 U g?1 dry cells with conversions up to 90 %. Therefore, this study contributes to the preparation of industrially relevant long‐chain aliphatic chiral amines and esters from renewable fatty acid resources. 相似文献
944.
Cristina Rodríguez‐Seco Maria Mndez Cristina Roldn‐Carmona Ravi Pudi Mohammad Khaja Nazeeruddin Emilio Jose Palomares 《Angewandte Chemie (International ed. in English)》2020,59(13):5303-5307
Three hole transport materials (HTMs) based on a substituted triphenylamine moiety have been synthesized and successfully employed in triple‐cation mixed‐halide PSCs, reaching efficiencies of 19.4 %. The efficiencies, comparable to those obtained using spiro‐OMeTAD, point them out as promising candidates for easily attainable and cost‐effective alternatives for PSCs, given their facile synthesis from commercially available materials. Interestingly, although all these HTMs show similar chemical and physical properties, they provide different carrier recombination kinetics. Our results demonstrate that is feasible through the molecular design of the HTM to minimize carrier losses and, thus, increase the solar cell efficiencies. 相似文献
945.
Chetan C. Chintawar Amit K. Yadav Nitin T. Patil 《Angewandte Chemie (International ed. in English)》2020,59(29):11808-11813
Herein, we disclose the gold‐catalyzed 1,2‐diarylation of alkenes through the interplay of ligand‐enabled AuI/AuIII catalysis with the idiosyncratic π‐activation mode of gold complexes. Unlike the classical migratory‐insertion‐based approach to 1,2‐diarylation, the present approach not only circumvents the formation of direct Ar?Ar′ coupling and Heck‐type side products but more intriguingly demonstrates reactivity and selectivity complementary to those of previously known metal catalysis (Pd, Ni, or Cu). Detailed investigations to underpin the mechanistic scenario revealed oxidative addition of aryl iodides to an AuI complex to be the rate‐limiting step owing to the non‐innocent nature of the aryl alkene. 相似文献
946.
Chetan Kumar Arya Swati Yadav Jonathan Fine Ana Casanal Gaurav Chopra Gurunath Ramanathan Kutti R. Vinothkumar Ramaswamy Subramanian 《Angewandte Chemie (International ed. in English)》2020,59(39):16961-16966
N,N‐dimethyl formamide (DMF) is an extensively used organic solvent but is also a potent pollutant. Certain bacterial species from genera such as Paracoccus, Pseudomonas, and Alcaligenes have evolved to use DMF as a sole carbon and nitrogen source for growth via degradation by a dimethylformamidase (DMFase). We show that DMFase from Paracoccus sp. strain DMF is a halophilic and thermostable enzyme comprising a multimeric complex of the α2β2 or (α2β2)2 type. One of the three domains of the large subunit and the small subunit are hitherto undescribed protein folds of unknown evolutionary origin. The active site consists of a mononuclear iron coordinated by two Tyr side‐chain phenolates and one carboxylate from Glu. The Fe3+ ion in the active site catalyzes the hydrolytic cleavage of the amide bond in DMF. Kinetic characterization reveals that the enzyme shows cooperativity between subunits, and mutagenesis and structural data provide clues to the catalytic mechanism. 相似文献
947.
D. Ashok Arram Ganesh B. Vijaya Lakshmi S. Ravi 《Russian Journal of General Chemistry》2014,84(6):1237-1242
Series of new (E)-1-aryl-3-[2-(piperidin-1-yl)quinolin-3-yl]prop-2-en-1-ones and (E)-1-aryl-3-[2-(pyrrolidin-1-yl)quinolin-3-yl]prop-2-en-1-ones have been efficiently prepared via the Claisen-Schmidt condensation of 2-(piperidin-1-yl)quinoline-3-carbaldehyde and 2-(pyrrolidin-1-yl)quinoline-3-carbaldehyde, respectively, with aryl methyl ketones under conditions of ultrasound and microwave irradiation. Structures of the products have been confirmed by IR, 1H NMR, 13C NMR, and mass spectroscopy, as well as by elemental analysis. Evaluation of the in vitro antibacterial activity against bacterial (Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli) and fungal (Aspergillus niger and Candida metapsilosis) strains has revealed good antimicrobial activity of some of the tested compounds. 相似文献
948.
Determination of Trace Lead and Cadmium in Water Samples by Anodic Stripping Voltammetry with a Nafion‐Ionic Liquid‐Coated Bismuth Film Electrode
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Die Yang Liang Wang Zuliang Chen Mallavarapu Megharaj Ravi Naidu 《Electroanalysis》2014,26(3):639-647
A new chemically modified bismuth film electrode coated with an ionic liquid [(1‐ethyl‐3‐methylimidazolium tetracyanoborate (EMIM TCB)] and Nafion was developed for the simultaneous determination Pb2+ and Cd2+ by anodic stripping voltammetry. Compared with conventional bismuth film electrodes, this electrode exhibited greatly improved electrochemical activity for Pb2+ and Cd2+ detection due to the unique properties of Nafion polymer and ionic liquid. The key experimental parameters related to the fabrication of the electrode and the voltammetric measurements were optimized on the basis of the stripping signals, where the peak currents increased linearly with the metal concentrations in a range of 10–120 µg L?1 with a detect limit of 0.2 µg L?1 for Pb2+, and 0.5 µg L?1 for Cd2+ for 120s deposition. High reproducibility was indicated from the relative standard deviations (1.9 and 2.5 %) for nine repetitive measurements of 20 µg L?1 Pb2+ and Cd2+, respectively. In addition, the surface characteristics of the modified BiFE were investigated by scanning electron microscopy (SEM), and results showed that fibril‐like bismuth nanostructures were formed on the porous Nafion polymer matrix. Finally, the developed electrode was applied to determine Pb2+ and Cd2+ in water samples, indicating that this electrode was sensitive, reliable and effective for the simultaneous determination of Pb2+ and Cd2+. 相似文献
949.
J. R. Reddy G. Ravi P. Suresh Naveen Kumar Veldurthi Radha Velchuri M. Vithal 《Journal of Thermal Analysis and Calorimetry》2014,115(2):1321-1327
Single source precursor, antimony potassium tartrate, was used for the preparation of Sb2O3, KSb3O5, K0.51Sb 0.67 III Sb 2 V O6.26, and KSbO3. Antimony trioxide (Sb2O3) was prepared by hydrothermal method, while potassium antimony oxides (KSbO3, K0.51Sb 0.67 III Sb 2 V O6.26, and KSbO3) were obtained from the thermal decomposition of antimony potassium tartrate. All the compounds were characterized by powder X-ray diffraction (PXRD), thermogravimetric analysis (TG), Fourier transform infrared spectroscopy (FT-IR), UV–Vis diffuse reflectance spectra, and scanning electron microscopy (SEM). The decomposition process of antimony potassium tartrate with temperature was given. The product formation at different temperatures of thermal decomposition was monitored by PXRD and FT-IR. The TG profile of antimony potassium tartrate shows mass loss at three regions. The infrared spectra of parent and decomposed products gave characteristic Sb-O bands. The band gap energy of decomposed products was obtained. The SEM diagrams of Sb2O3 show different morphologies. Direct solid state preparation of KSb3O5 and K0.51Sb 0.67 III Sb 2 V O6.26 under identical experimental conditions was unsuccessful. 相似文献
950.
Kavita Pandey Pankaj Yadav Indrajit Mukhopadhyay 《Journal of Solid State Electrochemistry》2014,18(2):453-463
Polyaniline (PANI) films were deposited by electrochemical polymerization of aniline monomer on a fluorine-doped glass substrate at room temperature under different electric field directions. The as-synthesized PANI films obtained at different growth cycles were characterized by AC impedance spectroscopy and scanning electron microscopy (SEM). The results revealed that the film morphology, transport kinetics, and electrical properties are strongly dependent on the electric field direction and magnitude of the applied field during electropolymerization. The SEM morphology and AC impedance (modulus spectroscopy) indicate that a more homogeneous, high-porous, and conducting PANI film is induced by horizontal electric field direction (HEFD) electrodeposition, whereas the modulus spectroscopy of the PANI film deposited by vertical electric field direction (VEFD) reveals that VEFD deposition favours two-dimensional growth of PANI. The obtained polymer is more of dielectric in nature due to preferable dendritic growth which is supported by SEM analysis. 相似文献