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1.
Abstract
A new semicarbazone, HL has been synthesized from quinoline-2-carboxaldehyde and N4-phenyl-3-semicarbazide and structurally and spectrochemically characterized. 1H NMR, 13C NMR, IR and electronic spectra of the compound are studied. The existence of keto form in the solid state is supported by the crystal structure and IR data. The compound crystallizes into an orthorhombic space group P212121. Intra and intermolecular hydrogen bonding interactions facilitates unit cell packing in the crystal lattice. 相似文献2.
S. Borodziuk A. Kasperczuk T. Pisarczyk S. Yu. Gus'kov J. Ullschmied E. Krousky K. Masek M. Pfeifer K. Rohlena J. Skala M. Kalal J. Limpouch P. Pisarczyk 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,41(2):311-317
Efficiency studies of laser driven thin metal disks
acceleration using the first harmonic (λ1=1.315 μm) of
the Prague Asterix Laser System (PALS) and subsequent craters creation
produced by collisions of these disks with massive targets are presented.
Several different disks made of aluminium and copper foils with diameters of
300 μm and 600 μm and thicknesses of 11 μm (Al) and 3.6 μ
m (Cu) were employed. Disks were placed at the distance of either 100 μ
m or 300 μm in front of aluminium massive targets. The following
irradiation conditions were used: the laser beam energy of 120 J, the focal
spot diameter of 200 μm, and the pulse duration of 0.4 ns (FWHM). A
three-frame interferometric system was employed to determine electron
density distributions in plasma corona. Shape and volume of craters were
obtained by crater replica technology and microscopy measurements. The aim
of these investigations was to analyse conditions leading to the most
effective energy transfer in the process of collision of the accelerated
disks with solid targets. The overall efficiency of these processes was
characterized by the volume of craters produced in such targets. 相似文献
3.
Harsh Kumar Kanchan Bhardwaj Natlia Cruz-Martins Eugenie Nepovimova Patrik Oleksak Daljeet Singh Dhanjal Sonali Bhardwaj Reena Singh Chirag Chopra Rachna Verma Prem Parkash Chauhan Dinesh Kumar Kamil Ku
a 《Molecules (Basel, Switzerland)》2021,26(11)
The ingestion of contaminated water and food is known to cause food illness. Moreover, on assessing the patients suffering from foodborne disease has revealed the role of microbes in such diseases. Concerning which different methods have been developed for protecting food from microbes, the treatment of food with chemicals has been reported to exhibit an unwanted organoleptic effect while also affecting the nutritional value of food. Owing to these challenges, the demand for natural food preservatives has substantially increased. Therefore, the interest of researchers and food industries has shifted towards fruit polyphenols as potent inhibitors of foodborne bacteria. Recently, numerous fruit polyphenols have been acclaimed for their ability to avert toxin production and biofilm formation. Furthermore, various studies have recommended using fruit polyphenols solely or in combination with chemical disinfectants and food preservatives. Currently, different nanoparticles have been synthesized using fruit polyphenols to curb the growth of pathogenic microbes. Hence, this review intends to summarize the current knowledge about fruit polyphenols as antibacterial agents against foodborne pathogens. Additionally, the application of different fruit extracts in synthesizing functionalized nanoparticles has also been discussed. 相似文献
4.
Alan R. Katritzky Nabin K. Meher Sureyya Hanci Reena Gyanda Srinivasa R. Tala Sindhu Mathai Randolph S. Duran Sophie Bernard Firouzeh Sabri Sandeep K. Singh Jacek Doskocz David A. Ciaramitaro 《Journal of polymer science. Part A, Polymer chemistry》2008,46(1):238-256
Fourteen commercial polyols have been characterized by GPC, NMR spectroscopy, and elemental analysis. From these, eight corresponding tosylates, six nitrate esters, seven mesylates, 13 alkynes, and 14 azides have been prepared and all these derivatives have been fully characterized. Five alkyne monomers and eight azide monomers were also prepared. Twelve alkynes and 13 azides (functionality 2–4) were combined in 1,3‐dipolar cycloaddition reactions under neat conditions to prepare triazole‐cured polymers, avoiding any heavy metal catalyst. Characterization by NMR spectroscopy, elemental analysis, and gel permeation chromatography indicated triazole polymers 14 , 22 , 23 , 28 , and 30 with degrees of polymerization of 17–28 to be the best candidates for future work. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 238–256, 2008 相似文献
5.
Radhakrishnan Sivakumar Vijayaragavan Reena Nallamuthu Ananthi Muthiya Babu Sambandam Anandan Sivan Velmathi 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2010,75(3):1146-1151
Salicylaldimine based schiff base receptors with different substituents showing fluorescent enhancement in the presence of fluoride anion was visualized through naked eye as well as by change in spectral properties (UV–vis and fluorescent techniques). The reason for such fluorescence enhancement may be due to hydrogen bond interaction between receptor recognition site and fluoride anion. Such a hydrogen bond interaction creates a six-membered transition state, which avoids quenching processes. To support this, fluorescence enhancement factor (FEF) was calculated and it was found to be more (FEF = 652) for –NO2 substituted receptor compared to other receptors. 相似文献
6.
Alan R. Katritzky Yuming Song Rajeev Sakhuja Reena Gyanda Nabin K. Meher Ling Wang Randolph S. Duran David A. Ciaramitaro Clifford D. Bedford 《Journal of polymer science. Part A, Polymer chemistry》2009,47(15):3748-3756
Second‐, third‐, and fourth‐generation hyperbranched aliphatic polyols namely Boltorn® H20, Boltorn H30, and Boltorn H40 were endcapped with azido and activated acetylenic groups in good to excellent yields (75–95%) following an acid catalyzed procedure. The resultant terminally functionalized dendritic azido and acetylenic groups undergo 1,3‐dipolar cycloaddition using methyl (or ethyl) propiolate and benzyl azide, respectively, under catalytic or noncatalytic conditions below 40 °C to yield 1,2,3‐triazole dendrimeric polymers in 82–95% yield, under extremely mild conditions that could be applied for compounds sensitive to acid, base, or heat. The dendritic azido and activated acetylenic derivatives may act as novel scaffolds to tune the mechanical properties of different polymers. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3748–3756, 2009 相似文献
7.
We demonstrate the receptor directed end-to-end assembly of multisegment Au/Ni/Au nanowires under agitation in ethanol. The gold end-segments were functionalized with biotin-terminated thiol thereby restricting aggregation to end-to-end attachment via an avidin linkage. On mixing biotin-terminated nanowires with avidin-terminated nanowires, the average chain length is shown to increase linearly with time. The rate constant was independent of the nanowire concentration. Kinetic Monte Carlo simulations were used to model the self-assembly process, and we show that the directed end-to-end assembly of nanowires is similar to the polycondensation of linear polymers. 相似文献
8.
9.
The Total Phenolic Content (TPC), antioxidant and antibacterial activities of methanolic extract of Marigold flower (MF) (Tagetes erecta) and Beet root (BR) (Beta vulgaris) were examined. The present work reveals that MF contained greater amount of TPC (42.5 mg/g GAE) as compared to BR (39.4 mg/g GAE). Methanolic extract of MF exhibited excellent DPPH free radical scavenging power (IC50 0.0716 mg/mL) and reducing power at 1 mg/mL concentration. Similar results have been obtained in FTC and TBA method. The results of antibacterial test indicated that the methanolic extract of MF and BR is significantly effective against both type of Gram-negative (Escherichia coli, Shigella dysenteriae) and Gram-positive (Bacillus subtilis, Staphylococcus aureus) bacterial strains. Therefore, the present study suggests that the Marigold and BR are promising source of herbal medicinal products with noteworthy antioxidant and antibacterial activity. 相似文献
10.
Ashok Kumar Pratibha Sharma Lal Kumar Chandel Bhagwan Lal Kalal 《Journal of inclusion phenomena and macrocyclic chemistry》2008,61(3-4):335-342
A spectrophotometric method for the determination of palladium, iron and tellurium from nitric acid media after extraction of their p-[4-(3,5-dimethylisoxazolyl)azophenylazo]calix(4)arene [DMIAPAC] complexes has been developed and possible synergistic effects have been investigated. Chloroform, carbon tetrachloride, cyclohexane, 1,2-dichloroethane, toluene and xylene were used as the diluents. The maximum enhancement was obtained in the presence of 30% 1,2-dichloroethane. The trace amounts of metals were determined spectrophotometrically. Beer’s law obeyed in the concentration range of 5.0–95.0 μg, 8.0–120.0 μg and 10.0–140.0 μg/10 mL of the final solution of palladium, iron and tellurium, respectively. The molar absorptivities (l mol?1cm?1) and Sandell’s sensitivities (μg cm ?1) were calculated: Pd(II) = 1.73 × 104 and 0.0061; Fe(III) = 1.08 × 104 and 0.0052; Te(IV) = 1.67 × 104 and 0.0077. Ten replicate analyses containing 20 μg of Pd(II), 12.5 μg of Fe(III) and 32 μg of Te(IV) gave mean absorbance of 0.326, 0.242 and 0.418 with relative standard deviation of 0.36, 0.65 and 0.82% for Pd(II), Fe(III) and Te(IV), respectively. The interference of various ions was studied and optimum conditions were developed for the determination of these metals in certain alloys and synthetic mixtures. 相似文献