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2985

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متن کامل


مرکز اطلاعات علمی SID1
مرکز اطلاعات علمی SID
اسکوپوس
مرکز اطلاعات علمی SID
ریسرچگیت
strs
اطلاعات دوره: 
  • سال: 

    2012
  • دوره: 

    9
  • شماره: 

    3
  • صفحات: 

    285-296
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    21236
  • دانلود: 

    9450
چکیده: 

Some new schiff bases, (Z)-4-amino-3-((E)-(R-methoxybenzylidene) hydrazono)-6-methyl-3,4-dihydro-1, 2, 4-triazin-5 (2H)-one (R=2 (L2), R=3 (L3) and R=4 (L4)), were synthesized by the condensation reactions of 4-amino-3-hydrazinyl-6-methyl-1,2,4-triazin-5(4H)-one (L1) and corresponding methoxybenzaldehyde in a molar ratio 1:1.5 in high yields. The reaction of L2 and L4 with an excess amount of the corresponding aldehydes gave the unsymmetrical bis-schiff bases (E)-3-((E)-(R-methoxybenzylidene)hydrazono)-4-((E)-R-methoxybenzylideneamino)-6-methyl-3,4-dihydro-1,2,4-triazin-5(2H)-one (R=2 (L22) and R=4 (L44)), respectively. Furthermore, the reaction of L2–L4 with silver(I) nitrate in a molar ratio 2:1 led to the silver(I)-complexes with the general formula [Ag(Lx)2]NO3 (Lx=L2 (2), L3 (3) and L4 (4)). All synthesized schiff base compounds and complexes were characterized by a combination of IR-, 1H-NMR spectroscopy, mass spectrometry and elemental analyses. In addition, the structures of L2, L4.CH3CN, L22.CH3OH and L44.CH3OH and complexes 2 and 4 were determined by X-ray diffraction studies.

آمار یکساله:  

بازدید 21236

دانلود 9450 استناد 0 مرجع 0
نویسندگان: 

MOHAMMADIKISH M. | SEYEDZADEH Z.

اطلاعات دوره: 
  • سال: 

    2012
  • دوره: 

    23
  • شماره: 

    3
  • صفحات: 

    225-230
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    16745
  • دانلود: 

    8456
چکیده: 

The formation constants and Gibbs free energy for the interaction of Rn SnClm (n=m=2, R= Me, Ph, n-Bu or n=4, m=0, R=Ph) compounds as acceptors, with ML complexes (H2L =N, N' -bis (salicylidene) -2-aminobenzylamine (salabza-H2) and its derivatives, M=Mn2+ or Zn2+), as donors in N, N' -dimethylformamide (DMF) as solvent were studied. These parameters were measured by using UV-vis spectrophotomety titration for 1: 1 adduct formation of the selected complexes at 25 (±0.1)oC in the 200-500 nm regions. The trend of adduct formation constants between metal schiff base complexes as donors and tin (IV) as acceptor decreases as follow:Me2 SnCl2>Ph2 SnCl2>n -Bu2 SnCl2>Ph4 Sn [M (5-OMe-salabza)]>[M (salabza)]>[M (5-Br-salabza)]>[M (5-NO2 -salabza)] Zn>Mn

آمار یکساله:  

بازدید 16745

دانلود 8456 استناد 0 مرجع 0
نویسندگان: 

HOSSEINI S.M.A. | AZIMI A. | SHEYKH SHOAEI I. | SALARI M.

اطلاعات دوره: 
  • سال: 

    2010
  • دوره: 

    7
  • شماره: 

    4
  • صفحات: 

    799-806
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    20053
  • دانلود: 

    25048
چکیده: 

The effects of 2, 2'- [bis-N (4-cholorobenzaldimin)] -1, 1'-dithio (BCBD) and bis- (2-aminophenyl) disulphide (BAPD) on the corrosion behavior of 302 stainless steel in 0.5 M sulfuric acid solution as corrosive medium were investigated using weight loss and potentiostatic polarization techniques. Some corrosion parameters such as anodic and cathodic Tafel slopes, corrosion potential, corrosion current density, surface coverage degrees and inhibition efficiencies were calculated. The polarization measurements indicated that the inhibitors were of mixed type which inhibited corrosion by parallel adsorption on the surface of stainless steel due to the presence of more than one active centre in the inhibitor molecule. The adsorption followed Langmuir adsorption isotherm. The activation energy and thermodynamic parameters were calculated at different temperatures. Results showed that BCBD had a higher inhibition efficiency compared with BAPD.

آمار یکساله:  

بازدید 20053

دانلود 25048 استناد 0 مرجع 0
گارگاه ها آموزشی
نویسندگان: 

JIAO TI FENG | ZHOU JUAN | ZHOU JINGXIN | GAO L. | XING YUANYUAN | LI X.

اطلاعات دوره: 
  • سال: 

    2011
  • دوره: 

    20
  • شماره: 

    2 (128)
  • صفحات: 

    123-136
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    133239
  • دانلود: 

    101493
چکیده: 

Chitosan is the product of N-deacetylation of chitin. For its innocuous, renewable, biocompatible property chitosan is applied in many fields e. g., pharmaceutical, food, catalysis, material. In this work, three chitosan-based schiff-based (CSB) compounds with aromatic substituent groups were synthesized from the reaction of chitosan with different aromatic aldehydes i.e., salicylaldehyde, 4-hexadecyloxy-2- hydroxybenzaldehyde and 2-hydroxy-1-naphthaldehyde. The chitosan-based schiff base copper (II) complexes (CSBCu) were subsequently obtained through the reaction of relative schiff bases with copper acetate. These products were characterized by elementary analysis (EA), Fourier transform infrared (FTIR) spectroscopy, thermal analysis (TG-DSC, TG-DTA), and X-ray diffraction (XRD) spectra, respectively. Generally, elemental analysis data may confirm the formation of chitosan-schiff base as well as the coordination reaction of CSB with copper ions. FTIR analysis indicated that schiff base and coordination reaction take place in schiff base skeleton. Moreover, with the difference in substituent groups and spacer, FTIR spectra showed the clear variety. Thermal analysis showed that the thermal stability of CSB increased slightly, while that of the copper complexes was reduced significantly in comparison with chitosan. The XRD results demonstrated the appearance of a new crystallization peak of CSB in the vicinity of five degree and the lower crystallinity of CSBCu. The differences in crystallinity and thermal stability are mainly attributed to the formation of schiff base group and complexation with copper ions, as well as spatially partial hindrance and hydrophobic forces in the aromatic substituent groups. The present results show that the specific properties of chitosan-based schiff base derivatives can be altered by modifying the molecular structures of objective compounds with proper substituent groups.

آمار یکساله:  

بازدید 133239

دانلود 101493 استناد 0 مرجع 0
اطلاعات دوره: 
  • سال: 

    2015
  • دوره: 

    0
  • شماره: 

    18
تعامل: 
  • بازدید: 

    2520
  • دانلود: 

    0
چکیده: 

BACKGROUND: THE METAL COMPLEXES ARE ONE OF MOST IMPORTANT COMPOUND IN INORGANIC CHEMISTRY THAT HAVE BEEN USED IN WIDE RANGE OF APPLICATION SUCH AS INDUSTRIAL, ANTIFUNGAL, AND BIOLOGICAL [1]. IN THIS AREA, THERE IS A SPECIAL ATTENTION ON METAL COMPLEXES CONTAINING OF schiff base LIGANDS. schiff baseS COMPLEXES ARE USED AS MEDICINE AND WIDE VARIETY OF BIOCHEMICAL ACTIVITY FOR AGAINST BACTERIA, FUNGI AND CERTAIN TYPES OF TUMORS [2]...

آمار یکساله:  

بازدید 2520

دانلود 0
نویسنده: 

MOHAMMADI KHOSRO | KARAMI TAYEBEH

اطلاعات دوره: 
  • سال: 

    2014
  • دوره: 

    0
  • شماره: 

    16
تعامل: 
  • بازدید: 

    1365
  • دانلود: 

    0
کلیدواژه: 
چکیده: 

A schiff base, NAMED AFTER HUGO schiff, IS A COMPOUND WITH A FUNCTIONAL GROUP THAT CONTAINS A CARBON-NITROGEN DOUBLE BOND WITH THE NITROGEN ATOM CONNECTED TO AN ARYL OR ALKYL GROUP, NOT HYDROGEN [1] .schiff baseS CAN BE SYNTHESIZED FROM AN ALIPHATIC OR AROMATIC AMINE AND A CARBONYL COMPOUND BY NUCLEOPHILIC ADDITION FORMING A HEMIAMINAL, FOLLOWED BY A DEHYDRATION TO GENERATE AN IMINE.schiff baseS HAVE WIDE APPLICATIONS IN FOOD INDUSTRY, DYE INDUSTRY, ANALYTICAL CHEMISTRY, CATALYSIS, FUNGICIDAL, AGROCHEMICAL AND BIOLOGICAL ACTIVITIES [2,3]. IMINE OR AZOMETHINE GROUPS ARE PRESENT IN VARIOUS NATURAL, NATURAL-DERIVED AND NON-NATURAL compounds. THE IMINE GROUP PRESENT IN SUCH compounds HAS BEEN SHOWN TO BE CRITICAL TO THEIR BIOLOGICAL ACTIVITIES [4-6].THIS WORK INVOLVES SYNTHESIS OF SOME schiff baseSDERIVEDFROM BENZALDEHYDE DERIVATIVESAND 2- HYDROXY-1-NAPHTHYLAMMONIUM CHLORIDE.THESE LIGANDSWERECHARACTERIZED BY 1H NMR, 13C NMR AND IR SPECTROSCOPY.

آمار یکساله:  

بازدید 1365

دانلود 0
strs
نویسنده: 

MAHMOODI N.O. | GHANBARI PIRABSTI F.

اطلاعات دوره: 
  • سال: 

    2014
  • دوره: 

    0
  • شماره: 

    22
تعامل: 
  • بازدید: 

    1260
  • دانلود: 

    0
چکیده: 

THIAZOLE AND THIAZOLE DERIVATIVES HAVE BEEN USED AS DRUGS SUCH AS SULFATHIAZOLE, RITONAVIR, NIRIDAZOLE AND BLEOMYCINE. ALSO, VARIOUS BIOLOGICAL ACTIVITIES ARE RELATED TO THIAZOLES SUCH AS ANTIMICROBIAL, ANTIOXIDANT, ANTI-HYPERTENSION, ANTI-INFLAMMATORY, ANTI-THROMBOTIC, ANTIBIOTIC, ANTIVIRAL, ANTI-CANDIDA, ANTI-ALERGIC, ANTI-COVULSANT, AND ANTI-PSYCHOTIC.IN CONTINUATION TO OUR PREVIOUS CLICK CHEMISTRY ON SYNTHESIS OF mono- AND bis-THIAZOLE DERIVATIVES AND SCREENING THEIR ANTI-BACTERIAL ACTIVITY [1-3], HERE FOR FIRST TIME WE REPORT ONE-POT MULTICOMPONENTSYNTHESIS OF mono- AND bis-THIAZOLE DERIVATIVES. PRODUCTS PREPARED IN AN EFFICIENT, FREE CATALYST, SIMPLE, HIGH YIELD, AND EASY WORK-UP PROCEDURE THROUGH THE REACTION OF mono- AND bis- ALDEHYDES OR KETONES, THIOSEMICARBAZIDE, AND 4-METHOXYPHENACYL BROMIDE IN ETOH UNDER REFLUX.

آمار یکساله:  

بازدید 1260

دانلود 0
اطلاعات دوره: 
  • سال: 

    1389
  • دوره: 

    2
  • شماره: 

    5
  • صفحات: 

    57-60
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    110
  • دانلود: 

    21
چکیده: 

ماکروسیکل های شیف باز از اهمیت زیادی در شیمی سوپرامولکول ها برخوردارند ، در شیمی کئوردیناسیون شیف بازهایی که گروه های الکنرون دهنده اضافی بر روی خود دارند، مهم ترین دسته از لیگاندهای هتروپلی دنتات می باشند که قابلیت تشکیل کمپلکس های یک ، دو یا چند هسته ای با فلزات واسطه و اصلی دارند. در کار فعلی در طی سنتز شیف بازماکروسیکلی روش های متفاوت (اعم از حلال های مختلف، کاتالیزورهای اسیدی مختلف، اثر آنیونی و شرایط دمایی مختلف) مورد استفاده قرار گرفت و بهترین حالت گزارش شد.

آمار یکساله:  

بازدید 110

دانلود 21 استناد 0 مرجع 0
نویسنده: 

ZAKAVI S.R. | MOUMENNEZHAD M. | SOLEIMANI K.

اطلاعات دوره: 
  • سال: 

    2015
  • دوره: 

    0
  • شماره: 

    23
تعامل: 
  • بازدید: 

    1260
  • دانلود: 

    0
کلیدواژه: 
چکیده: 

THE NONLINEAR OPTICAL (NLO) RESPONSES INDUCED IN VARIOUS MATERIALS ARE OF GREAT INTEREST IN RECENT YEARS DUE TO THEIR POTENTIAL APPLICATIONS IN PHOTONIC TECHNOLOGIES SUCH AS COMPUTERS, DATA STORAGE, AND TELECOMMUNICATIONS...

آمار یکساله:  

بازدید 1260

دانلود 0
اطلاعات دوره: 
  • سال: 

    2014
  • دوره: 

    11
  • شماره: 

    2
  • صفحات: 

    323-333
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    19756
  • دانلود: 

    9450
چکیده: 

mononuclear copper (II) complexes of 1, 2, 4-triazole-based schiff base macrocyclic hydrazones, III and IV, have been reported. The prepared amorphous complexes have been characterized by spectroscopic methods, electron spray ionization mass spectrometry, and elemental analysis data. Electrochemical studies of the complexes in DMSO show only one quasi-reversible reduction wave at +0.43 V (DE = 70 mV) and +0.42 V (DE = 310 mV) for III and IV, respectively, which is assigned to the Cu (II) ® Cu (I) reduction process. Temperature dependence of magnetic susceptibilities of III and IV has been measured within an interval of 2-290 K. The values of cM at 290 K are 1.72 × 10-3 cm3 mol-1 and 1.71 ´ 10-3 for III and IV, respectively, which increases continuously upon cooling to 2 K. EPR spectra of III and IV in frozen DMSO and DMF were also reported. The trend g|| > g^ > ge suggests the presence of an unpaired electron in the dx2-y2 orbital of the Cu (II) in both complexes. Furthermore, spectral and antimicrobial properties of the prepared complexes were also investigated.

آمار یکساله:  

بازدید 19756

دانلود 9450 استناد 0 مرجع 0
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