نتایج جستجو برای: uv vis spectra

تعداد نتایج: 180495  

Journal: :international journal of nano dimension 0
a. yahyazadeh department of chemistry, university of guilan, p.o. box 41335-1914, rasht, iran. v. azimi department of chemistry, university of guilan, p.o. box 41335-1914, rasht, iran

copper (ii) phthalocyanine and 2,9,16,23 tetrakis nitro copper (ii) phthalocyaninehas been synthesized respectively from phthalonitrile and 4-nitro phthalonitrile under solvent-free condition using two different catalystsovernanodimensionalzeolites. 4-nitro phthalonitrile synthesized from phthalimide in three steps. the newly prepared compounds have been characterized by ir, uv-vis, 1hnmr and m...

Journal: :Molecules 2018
Yage Tian Xican Li Hong Xie Xiaozhen Wang Yulu Xie Chuanbing Chen Dongfeng Chen

Our study explores the antioxidant and cytoprotective effects of baicalein and further discusses the possible mechanisms. A methyl thiazolyl tetrazolium (MTT) assay revealed that baicalein could considerably enhance the viability of hydroxyl radical-treated bone marrow-mesenchymal stem cells (bmMSCs) at 37-370 µM. The highest viability rate was 120.4%. In subsequent studies, baicalein was obser...

Journal: :international journal of nanoscience and nanotechnology 2012
n. qutub s. sabir

the present work deals with the synthesis and characterization of cds nanoparticles with good thermal stability and optical properties by a novel and simple synthetic route. the nanoparticles were synthesized via chemical precipitation method in a single reaction vessel under ambient conditions. the prepared cds nanoparticles were compared with the bulk cds. the optical properties were determin...

Journal: :Carbohydrate research 2005
Xiaochun Yu Rajai H Atalla

The complex of xylan and iodine and its formation in a solution of xylan, CaCl2, and I2+KI was investigated by UV/Vis, second-derivative UV/Vis, and Raman spectroscopy. The complex forms only at very high concentrations of CaCl2, suggesting that when the water available in the solution is not sufficient to fully hydrate the calcium cation the chelation with the hydroxyl groups of the xylan can ...

Journal: :Physical chemistry chemical physics : PCCP 2015
Torsten Bruhn Christian Brückner

meso-Tetraphenylporphyrin N-oxide (1) and meso-tetraphenyl-21,23-dithiaporphyrin S-oxide (3) possess optical spectra that are distinctly different from their parent porphyrins, meso-tetraphenylporphyrin (2) and meso-tetraphenyl-21,23-dithiaporphyrin (4), respectively. The hyperporphyrin spectra were reproduced and classified using TD CAM-B3LYP and SCS-CC2 computational methods. Calculations rev...

Journal: :Chemical communications 2015
K W J Heard J J Morrison L Weston C H Lo L Pirvu J Raftery M S Little J J W McDouall S G Yeates P Quayle

The regioselective, orthogonal functionalisation of 4,10-dichlorochrysene enables the synthesis of a variety of 2,8,4,10-"A2B2"-tetrasubstituted chrysenes. Such compounds exhibit broadened UV-vis absorption spectra, decreased band gap and higher HOMO levels compared to the parent chrysene.

Journal: :Chemical communications 2015
Tomoyuki Kosai Shintaro Ishida Takeaki Iwamoto

Regioselective cycloaddition of dialkylsilylene upon irradiation at 440 nm converts azulene and guaiazulene to bicyclic [4]dendralene and heptafulvene derivatives, respectively. Significant σ-π interactions in the resulting new silacycles were suggested using UV-vis spectra and theoretical calculations.

Journal: :Chemical communications 2007
Jari S Kavakka Sami Heikkinen Ilkka Kilpeläinen Marco Mattila Harri Lipsanen Juho Helaja

Pyrene mediated noncovalent attachment of a chlorophyll derivative, pyro-pheophorbide a, to a soluble single wall carbon nanotube is reported and the resultant CD, UV-Vis absorbance, fluorescence and 1H NMR spectra are discussed.

2011
Yulia B. Monakhova Thomas Kuballa Jenny Leitz Dirk W. Lachenmeier

Analytical methods based on spectroscopic techniques were developed and validated for the determination of diethyl phthalate (DEP) and polyhexamethylene guanidine (PHMG), which may occur in unrecorded alcohol. Analysis for PHMG was based on UV-VIS spectrophotometry after derivatization with Eosin Y and (1)H NMR spectroscopy of the DMSO extract. Analysis of DEP was performed with direct UV-VIS a...

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