18277-39-9Relevant academic research and scientific papers
Antioxidant activities and transition metal ion chelating studies of some hydroxyl Schiff base derivatives
Zhang, Ye,Zou, Biqun,Wang, Kai,Pan, Yingming,Liang, Hong,Yi, Xianghui,Wang, Hengshan
, p. 1341 - 1346 (2012)
Several hydroxyl Schiff base (HSB) compounds (1-10) with good radical scavenging activity (RSA) were designed. Compounds 6, 7, and 10 showed better RSAs than the common synthetic antioxidant 2,6-diterbutyl- 4-methylphenol (BHT) in DPPH and ABTS assays. To probe whether these HSB compounds may exert their antioxidant effect through transition metal ion chelation, the copper and ferrous chelating abilities of them were investigated. It was found by fluorescence quenching spectra that the binding constants Ka were in the range of 0.85×103-7.30×104 M-1. Further study was carried out by the complexation of a representative compound 5 with ferrous ion in mass spectrum. A 2:1 5-ferrous complex was readily formed in a methanol-water solution (v:v, 8:2), which confirmed that the chelation happened when the HSB compounds were treated with transition metal ions. The above results indicated that the transition metal ion chelation play an important role in their antioxidant abilities. Springer Science+Business Media, LLC 2011.
Spectrophotometric determination of chromium(III) and iron(III)by used of 2-((E)-(1H-benzo[d]imidazol2-yl) diazenyl)-5-((E)-benzylideneimino)phenol;(BIADPI)as organic reagent
Al-Adilee, Khalid J.,Eassa, Shaimaa M.,Dakhil, Haitham K.
, p. 2481 - 2491 (2016)
The azo reagent 2-((E)-(1H-benzo[d]imidazol2-yl)diazenyl)-5-((E)-benzyl ideneimino) phenol (BIADPI) was prepared and examined by using element analysis (C.H.N.), UV-Vis., Mass spectrum, 1H-NMR spectrum and infrared spectra. A sensitive and selective spectrophotometric method is proposed for the rapid determination of iron (III) and chromium(III) using (BIADPI), as spectrophotometer reagent. The reaction between this reagent with chromium (III) and iron (III) is instantaneous at (586,536) nm (λmax) and pH=(7.5,4) to form perpul complexes having a mole ratio 1 : 2 (metal : ligand) for Cr(III) and Fe(III) the absorbance remains stable for over 24 hours. Beer's law is obeyed in the rang of (1-14) μg.ml-1 and (1-21) μg.ml-1 with molar absorptivity (?) = (7.768×105, 9.3575×105) L.mol-1.cm-1 and a detection limit of (0.275-0.14) μg.ml-1 obtained respectively. The precision and accuracy were obtained to be R.S.D%=(0.9-0.467)%,Re%=(99.1-98.2-)% and Erel%= (-1.8 - 0.9)%.The method is successfully employed for the determination of iron(III) in Pharmaceutical preparations (Anemia drugs). The most important interferences were due to Ni(II), Zn(II), Co(II), Cd(II), Cu(II) and Hg(II) and suitable masking agents were used.
A new bifunctional heterogeneous nanocatalyst for one-pot reduction-Schiff base condensation and reduction-carbonylation of nitroarenes
Sobhani, Sara,Chahkamali, Farhad Omarzehi,Sansano, José Miguel
, p. 1362 - 1372 (2019/01/24)
In this work, synthesis of Pd-NHC-γ-Fe2O3-n-butyl-SO3H and its activity as a bifunctional heterogeneous nanocatalyst containing Pd-NHC and acidic functional groups, are described. This newly synthesized nanomagnetic catalyst is fully characterized by different methods such as FT-IR, XPS, TEM, VSM, ICP and TG analysis. At first, the catalytic activity of Pd-NHC-γ-Fe2O3-n-butyl-SO3H is evaluated for the reduction of nitroarenes in aqueous media using NaBH4 as a clean source of hydrogen generation at ambient temperature. Using the promising results obtained from the nitroarene reduction, this catalytic system is used for two one-pot protocols including reduction-Schiff base condensation and reduction-carbonylation of various nitroarenes. In these reactions the in situ formed amines are further reacted with aldehydes to yield imines or carbonylated to amides. The desired products are obtained in good to high yields in the presence of Pd-NHC-γ-Fe2O3-n-butyl-SO3H as a bifunctional catalyst. The catalyst is reused with the aid of a magnetic bar for up to six consecutive cycles without any drastic loss of its catalytic activity.
The evaluation of the role of C-H?F hydrogen bonds in crystal altering the packing modes in the presence of strong hydrogen bond
Kaur, Gurpreet,Singh, Sandhya,Sreekumar, Amritha,Choudhury, Angshuman Roy
, p. 154 - 169 (2015/11/18)
Interactions involving fluorine is an area of contemporary research. To unravel the importance of weak C-H?F hydrogen bonds and C-H?π interactions in organic compounds in the presence of strong hydrogen bond, a series of N-benzylideneanilines with simultaneously hydroxyl (-OH) and fluorine substitutions were synthesized for structural analysis. These compounds have been studied through experimental single crystal X-ray diffraction analysis and computational methods (Gaussian09 and AIM2000). The hydroxyl group present in all the molecules were found to form strong O-H?N hydrogen bond, but the spatial arrangement of the molecules connected by this hydrogen bond have been found to be controlled by the weak C-H?F and C-H?O hydrogen bonds, weak C-H?π and π?π interactions. This manuscript illustrates the importance of several weaker interactions in altering the packing modes in the presence of strong hydrogen bonds.
