Hydrazine Hydrate In Presence Research Articles

Surfactant-assisted synthesis of monodispersed ZnO nanorods at low temperature

Monodispersed ZnO nanorods were successfully synthesized by a surfactant assisted aqueous solution method at low temperature. The x-ray diffraction (XRD) results indicated that the synthesized ZnO powders without high-temperature calcination had a pure hexagonal wurtzite structure. The transmission electron microscopy (TEM) observation revealed that the monodispered ZnO nanorods with aspect ratio of about 9–12 were easily obtained in the presence of hydrazine hydrate and sodium oleate. The surfactant plays an important role in preventing the ZnO nanostructures from aggregating.

Solvent-free Synthesis and Spectral Studies of Some 9-Anthryl-1H-Pyrazolines

Totally ten 3-(9-anthryl)-4,5-dihydro-5-(3-substitutedphenyl)- 1 H-pyrazolines have been prepared by solvent-free cyclization of 2(E)-1-(substituted phenyl)-3-(9-anthryl)-2-propen-1-ones and hydrazine hydrate in presence of fly-ash:H2SO4 catalyst. These pyrazolines were characterized by their physical constants and spectroscopic data. The assigned infrared νC=N, NH(cm -1 ), NMR chemical shifts(ppm) of δNH, H4, H4', H5 and C=N data are correlated with Hammett substituent constants, F and R parameters using regression analysis. From the results of statistical analysis, the effects of substituent on the above group frequencies have been discussed.

Synthesis and Antimicrobial Screening of Some Novel Chromones and Pyrazoles with Incorporated Isoxazole Moieties

The title compounds 5a, 5b, 5c, 5d, 5e, 5f, 5g, 5h and 6a, 6b, 6c, 6d, 6e, 6f, 6g, 6h have been synthesized from β‐diketones and chromones, respectively, having 5‐methyl‐3‐phenylisoxazole moiety. Substituted 2‐acetylphenyl 5‐methyl‐3‐phenylisoxazole‐4‐carboxylate 3a, 3b, 3c, 3d, 3e, 3f, 3g, 3h were converted into 1‐(2‐hydroxyphenyl)‐3‐(5‐methyl‐3‐phenylisoxazole‐4‐yl)propane‐1,3‐dione 4a, 4b, 4c, 4d, 4e, 4f, 4g, 4h by Baker–Venketaraman transformation. Further, the cyclodehydration of diketone 4a, 4b, 4c, 4d, 4e, 4f, 4g, 4h with glacial acetic acid in conc. HCl at reflux gave corresponding substituted 2‐(5‐methyl‐3‐phenylisoxazole‐4‐yl)‐4H‐chromen‐4‐one 5a, 5b, 5c, 5d, 5e, 5f, 5g, 5h. The corresponding 5a, 5b, 5c, 5d, 5e, 5f, 5g, 5h react with hydrazine hydrate in presence of glacial acetic acid in ethanol at reflux to furnish 2‐(5‐5(5‐methyl‐3‐phenylisoxazole‐4‐yl)‐1H‐pyrazole‐3‐yl)phenol 6a, 6b, 6c, 6d, 6e, 6f, 6g, 6h. The structures of all newly synthesized compounds have been confirmed by IR, 1H NMR, mass spectral data, as well as elemental analysis. The synthesized compounds have been screened for their antimicrobial activity. Some of the compounds show better antimicrobial activity as compared with the reference drugs Streptomycin, Ampicillin, Gentamycin, Cefixime, and Ketoconazole.

ANRORC rearrangement in tetrahydro-2H-chromenones. Synthesis and structural assignment by NMR, MS, X-ray and DFT calculations of 2-[3(5)-trifluoromethyl-1H-pyrazol-4-yl)arylmethyl]cyclohexenones and derivatives

This paper describes firstly the synthesis of a new series of 3-hydroxy-2-[(3(5)-(methyl/phenyl)-5(3)-(trifluoromethyl)-1H-pyrazol-4-yl)arylmethyl]-cyclohex-2-en-1-ones (2), where aryl=C6H5, 4-NO2C6H4, 4-OCH3C6H4, from an ANRORC ring transformation reaction of 3-acyl-4-aryl-2-(trifluoromethyl)-2-hydroxy-3,4,7,8-tetrahydro-2H-chromen-5(6H)-ones (1), where acyl=acetyl and benzoyl, in the presence of hydrazine hydrate, at 63–90% yields. In subsequent steps, an oxidative aromatization reaction from 2 was done in an iodine/methanol medium for the preparation of 3(5)-trifluoromethyl-5(3)-methyl-4-[(2,6-dimethoxyphenyl)-(4-methoxyphenylmethyl)]-1H-pyrazole (3) at 72% yields. Also, the alkylation reaction using benzyl chloride easily converted a pyrazole like 2 to its N-benzyl derivative (4), at 69% yield. Finally, the structural assignment of compounds 2–4 was deduced by mass spectrometry, X-ray crystal diffraction and density functional theory (DFT) calculations, which clearly and unambiguously furnished values very close to those determined from 1H, 13C and 19F NMR data.

Crystal structure of 3-(4-hydroxy-3-methoxyphenyl)-7,7-dimethyl-7,8-dihydrocinnolin-5(6H)-one

Article history: Received June 25, 2012 Received in Revised form November 6, 2012 Accepted 30 November 2012 Available online 30 November 2012 The title compound 3-(4-hydroxy-3-methoxyphenyl)-7,7-dimethyl-7,8-dihydrocinnolin-5(6H)one (3) was prepared via one-pot three component reaction of 2-(4-hydroxy-3-methoxyphenyl)2-oxoacetaldehyde with dimedone in the presence of hydrazine hydrate and studied by the single crystal X-ray diffraction method. Its structure was also confirmed by IR, H and C NMR spectroscopy. Compound 3 was crystallized in the monoclinic system, space group P21/c, a = 7.921(2) A, b = 11.566(4) A, c = 16.986(6) A, β = 107.338(5)°, V = 1485.5(8) A, Z = 4, R1 = 0.0559 and wR2 = 0.1253. The crystal structure of 3 also shows a weak interaction between O3 and N2 atoms. © 2013 Growing Science Ltd. All rights reserved.

Schiff-base assisted synthesis of lead selenide nanostructures

In this work, nanostructured PbSe materials have been prepared via a solvothermal method at 180°C with the aid of new lead precursors like Schiff-base compounds; Pb(salpn) and Pb(salophen). Besides lead complexes as lead precursor, SeCl4, and N2H4·H2O as starting materials and propylene glycol as solvent were applied. On the other hand, the effect of preparation factors such as type of reducing and capping agent on the morphology of PbSe nanostructures was investigated. The as-prepared PbSe nanostructures were characterized by XRD, SEM, TEM, EDS, and FT-IR. The SEM micrographs of the products indicated that PbSe nanostructures with lower particle size were obtained after solvothermal treatment for 3h at 180°C in the presence of hydrazine hydrate as reducing agent. The as-obtained results indicated that pure and homogeneous PbSe nanostructures have been form by using Pb(salpn) as precursor.

Single crystal X-ray structure of 3-amino-5-(4-chlorophenyl)pyridazine-4-carbonitrile

Article history: Received March 27, 2013 Received in Revised form August 27, 2013 Accepted 17 October 2013 Available online 18 October 2013 The title compound 3-amino-5-(4-chlorophenyl)pyridazine-4-carbonitrile was prepared by a one-pot three-component reaction of malononitrile with corresponding arylglyoxal in the presence of hydrazine hydrate at room temperature in water and ethanol. Its structure was also confirmed by its IR, H, C-NMR, Mass spectral data and elemental analysis. The compound was crystallized in the monoclinic system, space group P21/c, a = 3.817(3) A, b = 13.533(10) A, c = 19.607(15) A, β = 93.401(10)°, Z=4, R1 = 0.0906 and wR2 = 0.1422. The crystal structure of the compound also shows a weak intermolecular interaction between N1 atom of one molecule and N3 atom of the other molecule. © 2013 Growing Science Ltd. All rights reserved.

Characterization of kaolin intercalates of oleochemicals derived from rubber seed (Hevea brasiliensis) and tea seed (Camelia sinensis) oils

Kaolin intercalates were prepared by employing derivatives of oleochemicals namely rubber seed oil (SRSO) and tea seed oil (STSO) and characterized by employing powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR) and nitrogen adsorption–desorption (NAD) techniques. Intercalation was achieved in the presence of hydrazine hydrate as co-intercalate. The PXRD patterns showed an increase in the interlayer basal spacing d-001 for the SRSO treated and STSO treated kaolins confirming intercalation process. The FTIR studies indicated that the fatty acid salts of rubber seed oil and tea seed oil were effectively intercalated in the kaolinite layers as per the bands at 1564cm−1 and 1553cm−1 for SRSO treated and STSO treated kaolinites, respectively. The SEM revealed intercalation of organic materials in the kaolinite layers. The NAD results showed that intercalation of kaolin resulted in an overall decrease in the specific surface area as well as pore volume. Specific surface area decreased in the following order: untreated (pristine) kaolin>STSO treated kaolin>SRSO treated kaolin and pore size in the order: untreated (pristine) kaolin>SRSO treated kaolin>STSO treated kaolin.

A Green One-Pot Protocol for Regioselective Synthesis of New Substituted 7,8-Dihydrocinnoline-5(6H)-ones

A simple regioselective synthesis of cinnoline derivatives was achieved by a one-pot three component synthetic methodology. New substituted 7,8-dihydrocinnolin-5(6H)-ones are prepared via one-pot three component reaction of arylglyoxals with 1,3-cyclohexanedione and dimedone in the presence of hydrazine hydrate in moderate to good yields.

Preparation and Characterization of Graphene by the Oxidation Reduction Method

We prepared graphite oxide (GO) from natural graphite by the modified Hummers method. Then graphene was prepared by ultrasonically dispersing GO in the presence of hydrazine hydrate. The samples were characterized by FTIR, Raman, Scanning electron microscope (SEM) and Transmission electron microscope (TEM). The results suggest that the graphite is oxidized to covalent bond-type graphite intercalation compounds with various oxygen functional groups (C=O, C-OH, -COOH and C-O-C). Results show that the functional groups on graphite oxide surface are mostly removed by hydrazine hydrate and graphene presents translucent slide with curly edge.

A facile method for gold decoration of Te@CdTe nanorods in aqueous solution

Colloidal synthesis of metal–semiconductor hybrid nanostructures is mainly achieved in organic solution. In some applications of hybrid nanoparticles relevant in aqueous media, phase transfer of hydrophobic metal–semiconductor hybrid nanostructures is essential. In this work, we present a simple method for direct synthesis of water-soluble gold (Au) decorated Te@CdTe hybrid nanorods (NRs) at room temperature by using aqueous Te@CdTe NRs as templates, which were preformed by using CdTe nanocrystals (NCs) as precursor in the presence of hydrazine hydrate (N2H4). Our results showed that NRs were decorated with Au islands both on tips and along the surface of the NRs. The size and density of Au islands can be controlled by varying the amount of Au precursor (mixture of HAuCl4 and thioglycolic acid (TGA)) and TGA/HAuCl4 ratio. A possible growth mechanism for the Au decoration of Te@CdTe NRs is concluded as three steps: (1) the formation of AuTe1.7 via the substitution reaction of Cd2+ by Au3+, (2) adsorption of Au–TGA complex onto the preformed AuTe1.7 anchors and following reduction by CdTe and N2H4, leading to the formation of small Au NCs, (3) Au NCs grow to bigger ones, followed by reduction of more Au precursor by N2H4.

Mechanism for the formation of low aspect ratio of La(OH)3 nanorods in aqueous solution: thermal and frequency dependent behaviour

La(OH)3 nanorods of length varying between 30 and 50 nm with aspect ratio of 2–5 were synthesized in aqueous solution using hydrazine hydrate in presence of mixture of cationic N-cetyl-N,N,N,trimethylammonium bromide (CTAB) and tetra-n-butylammonium bromide (TBAB) surfactants. The resultant product was characterized for its morphology and structure using XRD, TEM and FT-IR. Thermal stability studied using TGA indicated good stability. Surfactants in reaction mixture reduces the surface tension of the solution which lowers the energy needed to form a new phase, resulting in the formation of La(OH)3 crystals of anisotropic shape with low aspect ratio. The A.C. conductivity was found to be of the order of nano-seimen (ns), which non-linearly increases with the increase in frequency (102–106 Hz) The capacitance behaviour was observed in pF in mid frequency region, which can be useful as low loss dielectric material. Nano rods may work as standard materials to monitor conductivity levels in biofluid proteins.

Synthesis and evaluation of substituted diphenyl-1,3,4-oxadiazole derivatives for central nervous system depressant activity

BackgroundSubstituted 1,3,4-oxadiazoles are of considerable pharmaceutical interest. 2,5-Substituted diphenyl-1,3,4-oxadiazoles are associated with diverse biological activities by the virtue of -N = C-O- grouping. In the view of wide range of biological properties associated with 1,3,4-oxadiazole, we have synthesized substituted derivatives of 1,3,4-oxadiazole (XIII-XXII), a versatile hydrophobic molecule possessing preliminary CNS properties, with the hope to potentiate the biological activities with lesser or limited amount of toxicities.MethodThe synthesis was based on ester substitution of substituted benzohydrazide in presence of hydrazine hydrate followed by cyclization in presence of phosphorus oxychloride. All the synthesized compounds were evaluated for their potential CNS depressant activities. Statistical analysis of the anticonvulsant, antidepressant, and antianxiety activity of the synthesized compounds on animals was evaluated using one-way analysis of variance (ANOVA).ResultsTwo compounds 5-(4-nitrophenyl)-2-(4-chlorophenyl)-1,3,4-oxadiazole (XIV) and 5-(4-nitrophenyl)-2-(4-nitrophenyl)-1,3,4-oxadiazole (XV) were found to be the most promising compounds of the series in antidepressant, anticonvulsant and antianxiety activity with no neurotoxicity when compared with standard.ConclusionsAmong the synthesized compounds, it was found that incorporation of electron withdrawing group at C2 and C5 position of the oxadiazole ring led to high degree of pharmacological activity. Thus compounds 5-(4-nitrophenyl)-2-(4-chlorophenyl)-1,3,4-oxadiazole (XIV) and 5-(4-nitrophenyl)-2-(4-nitrophenyl)-1,3,4-oxadiazole (XV) showed excellent CNS depressant activities. The result of the present investigation may encourage us to develop and/or improve similar other related compounds and it may be assumed that further modifications may produce compounds of better activity with lesser side effects.

Synthesis and characterization of 1-formyl-3-phenyl-5-aryl-2-pyrazolines

Reaction of chalcone derivatives 1 - 4 with hydrazine hydrate in presence of formic acid yielded 2-pyrazolines 5 - 8 . Structures of these compounds have been elucidated by spectroscopic methods; IR, UV, 1 H NMR, 13 C NMR. Their purities were confirmed by elemental analyses.

A novel route for the synthesis of nanotubes and fullerene-like nanostructures of molybdenum disulfide

The paper described the synthesis of nanotubes and fullerene-like nanostructures of MoS 2 through a technically simple, rapid, and energy-efficient microwave-assisted synthesis technique, which involved the use of elemental sulfur dissolved in a mixture of monoethanolamine and hydrazine hydrate as the sulfide source. The microwave induced reaction between the molybdate with sulfide ions, in the presence of hydrazine hydrate in the reaction medium, resulted in the formation of gray colored powders of amorphous MoS 2. The as-obtained powders were calcined at 600 °C for 2 h and characterized by different techniques. HRTEM analysis of the calcined samples indicated the formation of fullerene-like MoS 2 structures when the starting solution mixture was irradiated with microwave for a period of 200 s, while on 600 s of irradiation of the same revealed the formation of folded sheets like MoS 2 nanotubes. BET surface areas of the calcined samples have been measured and a plausible reaction mechanism for the formation of nanotubes and fullerene-like nanostructures of MoS 2 has been proposed.

Synthesis, Characterization and Antifungal Evaluation of 5-Substituted-4-Amino-1,2,4-Triazole-3-Thioesters

A series of 5-substituted-4-amino-1,2,4-triazole-3-thioesters was synthesized by converting variously substituted organic acids successively into the corresponding esters, hydrazides, 5-substituted-1,3,4-oxadiazole-2-thiols, 5-substituted-1,2,4-triazole-2-thiols and 5-substituted-1,3,4-oxadiazole-2-thioesters. Finally the target compounds were obtained by refluxing 5-substituted-1,3,4-oxadiazole-2-thioesters in the presence of hydrazine hydrate and absolute alcohol. The structures of the synthesized compounds were established by physicochemical and spectroscopic methods. The synthesized compounds were evaluated for their in vitro antifungal activity. Some of the evaluated compounds possessed significant antifungal activity as compared to a terbinafine standard.

Synthesis and optical properties of Sb 2Se 3 nanorods

The present work aims at the formation of good quality nanorods of Sb 2Se 3 by using alkaline selenium solution and SbCl 3 in presence of hydrazine hydrate as reducing agent and carrying out reaction under hydrothermal conditions at 150 °C for 12 h. X-ray diffractogram of the product could be indexed on the basis of the pure orthorhombic phase. The nanorods formed are of diameter around 40–100 nm and length could be of several micrometers. The band gap of the nanorods is found to be 1.78 eV. Photoluminescence of the Sb 2Se 3 nanorods excited at 450 nm showed emission peak at 587 nm.

Novel Preparation of Silver-Coated Copper in Aqueous Solution

Hollow and solid spherical silver-coated copper powders with size of 1μm were facilely prepared by the reduction of silver nitrate in the polyvinyl pyrrolidone (PVP) dispersed copper hydrosol solution at room temperature in the presence of hydrazine hydrate. Scanning electron microscopy and X-ray diffraction were conducted to investigate the formation process of silver-coated copper core-shell particles. The results showed that the absorption and deposition of the Ag nuclei initially occurred at the active sites on the core surfaces as seeds which urged the further deposition of silver species to form sprinkled-structure core-shell particles. During the growth of the silver shell, the dissolution of copper core would result in the formation of hollow spherical particles, while the hydrazine hydrate would help to generate the solid spherical silver-coated copper powders.

Novel one-pot, three component synthesis of alkyl 6-aryl-3-methylpyridazine-4-carboxylates in water

A series of new alkyl 6-aryl-3-methylpyridazine-4-carboxylates were efficiently synthesized by a three-component reaction of β-ketoesters with arylglyoxals in the presence of hydrazine hydrate in water at room temperature.

An Environmentally Benign, Highly Efficient Catalytic Reduction of p‐Nitrophenol using a Nano‐Sized Nickel Catalyst Supported on Silica‐Alumina

AbstractA green and effective method is reported for the reduction of p‐nitrophenol to p‐aminophenol using a nano‐sized nickel catalyst supported on silica‐alumina in the presence of hydrazine hydrate as an alternative source of hydrogen. It was found that nickel loaded on a silica‐alumina support is a very effective catalyst in the hydrogenation of p‐nitrophenol to p‐aminophenol. Thus it attained 100% conversion in only 69 seconds instead of 260 seconds for commercial Raney nickel. In addition, the possibility to reuse it more than one time with great efficiency gives it another advantage over commercial Rainey nickel which cannot be used more than once. This economical and environmentally friendly method provides a potentially new approach for the synthesis of the intermediate product of paracetamol in industry, which overcomes the drawbacks of the known reduction methods. The prepared catalysts were fully characterized by X‐ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X‐ray (EDX), and electron spin resonance (ESR) tehniques.