13412-10-7Relevant academic research and scientific papers
BF3-functionalized silica-coated magnetic nanoparticles as a novel heterogeneous solid acid for synthesis of formazan derivatives via a green protocol
Bamoniri, Abdolhamid,Moshtael-Arani, Naimeh
, p. 662 - 672 (2015/06/25)
A new type of green heterogeneous solid acid was prepared by the immobilization of BF3·Et2O on the surface of Fe3O4@SiO2 core-shell nanocomposite (Fe3O4@SiO2-BF3) and characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), field emission scanning electron microscope (FE-SEM), energy-dispersive X-ray (EDS), and transmission electron microscope (TEM). The activity of this super solid acid was probed through the synthesis of aryl diazonium salts as the starting reactant and then, their diazo coupling with aldehyde phenylhydrazones for formation of formazan derivatives in a solvent-free medium at room temperature. This clean and environmentally benign methodology has advantages such as: no need for corrosive and toxic liquid acids, solvents, or buffer solutions, room temperature reaction, high yields, and short reaction times. In addition, long-term stability of aryl diazonium salts supported on the surface of Fe3O4@SiO2-BF3 magnetic nanoparticles (MNPs) at room temperature was one of the most important results of this procedure.
Microwave mediated solvent free synthesis of formazans catalyzed by simple ionic liquids derived from dialkylammonium salts
Das, Pranab Jyoti,Begum, Jesmin
, p. 44604 - 44609 (2015/06/02)
A microwave mediated, ionic liquid catalyzed, VOC free and one pot synthesis of formazans was developed. In an alternative procedure, resin immobilized diazonium ions was used as a solid supported reaction for formazan synthesis. The efficiency of both the procedures was examined with respect to yield of product, reduction of reaction time and environmental impact. Products were obtained in a short reaction time and in moderate to high yield. This study was undertaken to find an alternative green protocol for the synthesis of formazans using ionic liquid as catalyst in aqueous media in the absence of corrosive mineral acids, buffered solutions and VOCs.
Nano BF3·SiO2: A green heterogeneous solid acid for synthesis of formazan dyes under solvent-free condition
Bamoniri, Abdolhamid,Mirjalili, Bi Bi Fatemeh,Moshtael-Arani, Naimeh
, p. 272 - 278 (2014/07/22)
A solvent-free, efficient and rapid approach for synthesis of formazan dyes was developed by diazotization of aromatic amines with NaNO2, nano silica-supported boron trifluoride (nano BF3·SiO2), then diazo coupling with aldehyde phenylhydrazones by grinding method at room temperature. This study aimed to overcome the limitations and drawbacks of the previous reported methods such as: low temperature, using corrosive and toxic acids and solvents, using buffer solutions, instability of aryl diazonium salts, modest yields, and long reaction times.
Electrochemical and spectroscopic behaviors of 1-(o-, m-, p- Cl, or Br) substituted phenyl-3, 5-diphenylformazans in dimethyl sulfoxide
Tezcan, Habibe,Ekmekci, Gueler
experimental part, p. 189 - 197 (2010/09/05)
1-(o-, m-, p-Cl, -Br) substituted phenyl-3, 5-diphenylformazans were synthesized. Their structures were elucidated and spectral behaviours were investigated by elemental analysis, FT-IR, UV-vis spectral data. The electrochemical properties such as number of electrons transferred (n), diffusion coefficient (D) and heterogeneous rate constant (ks) were determined and possible mechanisms were proposed using platinum and ultramicro platinum electrodes, cyclic voltammetry, linear sweep voltammetry and chronoamperometry. The oxidations were carried out at different electrochemical steps that were dependent upon the structure of formazans. The relation between their absorption properties with electrochemical properties was investigated. A suitable correlation was obtained between the absorption λmax with electrochemical properties, and between the oxidation peak potentials Eox1 with ks values of formazans.
Anti-Plasmodium activity of tetrazolium salts
Cui, Xilin,Vlahakis, Jason Z.,Crandall, Ian E.,Szarek, Walter A.
, p. 1927 - 1947 (2008/09/21)
We have previously reported that sulfated cyclodextrins inhibit the invasion of Plasmodium merozoites by interacting with receptors present on the surface of erythrocytes. The observation that tetrazolium salts formed stable complexes with the inhibitory sulfated cyclodextrins suggested that tetrazolium salts might have anti-Plasmodium activity as well. Evaluation of commercially available tetrazolium salts indicated that some were active in the low nanomolar range and showed specificity in their inhibition of Plasmodium. Synthesis of a further 54 structures allowed us to determine that activity results from an aromatic component attached to the tetrazolium carbon atom (R1) and its size is not critical to the activity of the compound. Nitro modifications of active compounds are poorly tolerated, however, the presence of halogen atoms on aromatic groups attached to the nitrogen atoms of the tetrazolium ring (R2 and R3) has little effect on activity. Methoxy groups are tolerated on R2 and R3 components; however, they are disruptive on the R1 component. The overall results suggest that the R1 component is interacting with a specific hydrophobic environment and the R2 and R3 components are less constrained. The activity of these compounds in several human and mouse Plasmodium cultures suggests that the compounds interact with a component of the parasite that is both essential and conserved.
Kinetics and Mechanism of Oxidative Cyclization of Formazans to Tetrazolium Salts by Thallium(III) Acetate
Balakrishnan, R.,Srinivasan, V. S.,Venkatasubramanian, N.
, p. 404 - 406 (2007/10/02)
The kinetics of thallium(III) acetate oxidation of 1,3,5-triarylformazans have been investigated in acetic acid-water mixture.The reaction, which leads to tetrazolium salt as the product, follows the rate-law .The effect of substituent in the aldehyde (3-phenyl), the phenylhydrazine (l-phenyl) and the aryldiazonium (5-phenyl) moieties on the reaction rate has been studied and the corresponding Hammett rhos are -0.78, -0.85 and -0.8 respectively.A mechanism for the oxidative cyclization is proposed involving the formation of a N-thallated complex between the formazan and T1 (III) acetate which decomposes in a slow step accompanied by a ring closure between N-1 and N-5.
