Addition Of Hydrazine Research Articles

Towards portable kits for on-site colorimetric detection of aqueous hydrazine using piperidine-thiophene-barbituric acid push-pull probe.

Owing to the carcinogenicity and environmental risks as well as the wide industrial use of hydrazine, we report herein a colorimetric probe for its ratiometric detection in pure water. The developed probe possesses push-pull architecture with 2-(piperidyn-1-yl)thiophene as the donor, N,N'-dibutylbarbituric as the acceptor, and butadiene as the spacer. In contrast to weak solvatochromic behavior in organic solvents, the probe showed distinct optical photophysical properties in water resulting from the formation of nanoscopic aggregates. The probe underwent pronounced spectral changes upon the addition of hydrazine including an 11.5-fold decrease in absorbance and ~2.4-fold fluorescence quenching. The mechanistic investigation revealed the rapid formation of hydrazone upon the interaction of the probe with hydrazine via retro-Knoevenagel reaction as confirmed experimentally and corroborated with DFT calculations. The induced colorimetric and fluorometric changes were utilized in hydrazine sensing with excellent selectivity over other biologically relevant analytes with a detection limit of 0.76 µM in aqueous media. The practical utility of the probe was assessed in real-life natural water samples, while we have also developed a cost-effective portable kit for the on-site hydrazine detection both in the solution and vapor phases.

Synthesis of N,N‐Disubstituted Hydrazines by Electrocatalytic Addition of Hydrazines to α,β‐Unsaturated Carbonyl Compounds

AbstractA strategy for the synthesis of N,N‐disubstituted hydrazines via the electrocatalytic addition of hydrazine to α,β‐unsaturated carbonyl compounds is reported. The reaction was carried out under constant current electrolytic conditions in an undivided cell. Using this methodology, various N,N‐disubstituted hydrazines were prepared in 57–94% yield in 40 minutes. By adding cyclohexanone and acetic acid to the reaction mixture of N,N‐disubstituted hydrazines and heating for 2 hours, a one‐pot synthesis of N‐substituted indoles was also developed. Furthermore, based on cyclic voltammetry and control experiments, a plausible mechanism involving a radical pathway is proposed.

Synthesis of Manganese(II), Iron(III), and Vanadium(IV) Complexes with New Schiff Bases and their Spectroscopic and Thermal Studies and Evaluation of their Antimicrobial Activity

Heterocyclic 3-acetyl coumarin with hydrazide derivatives and their metal complexes are a substantial family of pharmaceutical drugs used to treat infection, anti-inflammatory issues, diabetes, and neurological disorders in the field of medicinal chemistry. Cyclization of 5- floro-2-furaldehyde, ethyl acetoacetate, and urea or thiourea by LaCl3.7H2O, addition of hydrazine to form amine derivatives were performed, and respective Schiff base derivatives (L1, L2) were produced by adding acetyl coumarin in an ethanolic solution at ambient temperature. New ligands and its complexes of the V (IV), Fe (III) and Mn (II) ions were characterized using (FT-IR, UV, MS) and nuclear magnetic resonance (1H-NMR) as well as elemental analysis (CHN). The synthesized complexes chelate with ligands L1, L2 via (N, O2) atoms. The structural geometry of the complexes was illustrated in the solid phase using FT-IR and UV-VIS spectroscopy, elemental analysis (CHNS), and flame atomic absorption, in addition to magnetic susceptibility and conductivity measurement. The antibacterial activity of the newly prepared ligands and their metal complexes was evaluated against Pseudonomous aerugionosa as a gram negative and Bacillus subtilis as a gram positive microorganism. Moreover, the antifungal activity against two fungi Aspergillus flavus, and Saccharomyces cerevisiae was studied for all compounds. The coordinated ligands significantly increased their bactericidal and fungicidal action compared to the free ligands, which did not exhibit any activity against the selected fungal and bacterial strains. The results focused on the synergetic relationship between the metal ion and the ligand, in addition to the structural variation.

Converging optical and electrochemical detection strategies for multimodal hydrazine sensing: insights into substituent-driven diverse response.

A pair of pyrene-based chalcogen derivatives have been developed, which demonstrate multimodal ratiometric response towards hydrazine. Although these probes share a common pyrene core and differ primarily in the electronic nature of their terminal side arms, they display distinct photophysical properties. Notably, both probes undergo significant spectral changes upon the addition of hydrazine, but probe 1 exhibits a more pronounced interaction (∼5-fold fluorescence enhancement) than probe 2, attributed to the higher level of aggregation in probe 2, rendering the binding site less accessible to the incoming analyte. Additionally, we have explored electrochemical techniques, including cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), for hydrazine detection. Our molecular design strategy relies on ratiometric-responsive specific cyclization triggered by hydrazine, leading to the disruption of the π-conjugated system and the subsequent suppression of intramolecular charge transfer (ICT) processes, along with dis-assembly of the aggregated probe molecules. These probes enable the nakеd-eye detection of hydrazine, with a low detection limit of 7.33 ppb and 7.58 ppb for probe 1 and 2, respectively. Furthermore, we have investigated cost-effective probe-coatеd paper strips for the detection of hydrazine in water.

Chemodosimetric discriminative analysis of cyanide, ammonia, aliphatic amine, and hydrazine utilizing the diverse reaction types of the pyrylium salt

Pyrylium salts are well known to react with different nucleophiles to form many different types of products like pyridinium salt, pyridine, cyanodienone, thiopyrylium, isoxazoline, N-aminopyridinium salt or 1,2-diazepine, depending on the nucleophile used. This property of pyrylium salts could be used to develop a multi-analyte chemosensor for the species having nucleophilic character. On this idea, we synthesized a pyrylium compound (PyrSen) bearing auxochromes and studied its photophysical responses to different nucleophiles. Different absorption spectra were observed to emerge upon the separate addition of cyanide, propylamine, ammonia, and hydrazine to the aqueous solution of PyrSen (ethanol-water 5:1). In the solutions containing ammonia and hydrazine were also observed fluorescence at different wavelengths. The products responsible for these photophysical properties were isolated and characterized. The developed sensor was proved to be usable for the discrimination and quantification of these four species in aqueous solutions.

New 1,8-naphthalimide-based colorimetric fluorescent probe for specific detection of hydrazine and its multi-functional applications

Detection of hydrazine is particularly important given its toxicity and extensive application in various industries. In the present paper, a colorimetric fluorescent probe NI-CIN based on 1,8-naphthalimide derivative was rationally designed and simply synthesized for specific detection of hydrazine based on the intramolecular charge transfer (ICT) mechanism. Upon the addition of hydrazine, a significant fluorescence enhancement at 556 nm could be observed within 4 min with a distinct color change from colorless to bright yellow, readily observed by naked eye. Except for HRMS and 1H NMR, density functional theory (DFT) calculations were also performed to support the sensing mechanism. In addition, eco-friendly paper test strips were easily prepared by NI-CIN for selective and real-time detection of hydrazine under aqueous and vapor phases. Furthermore, NI-CIN shows many potential applications for detecting hydrazine in real water and soil samples along with bio-imaging in HepG-2 cells and zebrafish.

Fluorescence detection of hydrazine in an aqueous environment by a corrole derivative.

Broadly, the industrial applications of hydrazine cause environmental pollution and damage to living organisms because of the high toxicity of hydrazine. Therefore, monitoring hydrazine in the environmental system is of great significance to human health. Here, a new fluorescent probe PC-N2 H4 based on corrole dye was developed for the detection of hydrazine that had excellent specificity, low limit of detection (LOD: 88 nM), and a wide pH range (6-12). Upon addition of hydrazine into the probe solution, the strong red fluorescence was 'turned on' centred at 653 nm with a 127-fold fluorescence intensity enhancement. The detection mechanism was proved using ESI-MS, 1 H NMR, and density functional theoretical calculations. Importantly, the probe was utilized to fabricate a ready-to-use test strip to realize the visual inspection of hydrazine. Furthermore, PC-N2 H4 was successfully applied for practical detection of hydrazine in water samples with satisfactory recoveries ranging from 96.2% to 105.0%, and indicating that the designed PC-N2 H4 is highly promising for hydrazine detection in an aqueous environment. Considering the diverse toxicological functions of hydrazine, PC-N2 H4 was also successfully used to image exogenous hydrazine in HeLa cells and zebrafish.

Coumarin hemicyanine-based colorimetric, smartphone color ratio, and intramolecular charge transfer fluorescent receptor for highly specific sensing of hydrazine in environmental water samples

In this report, we focused on developing a fluorescent probe based on coumarin hemicyanine (CPR) and a smartphone-based colorimetric sensing system for detecting hydrazine in actual water sample analysis. The receptor CPR was successfully synthesized, characterized by various spectroscopic analyses, and also applied for selective, sensitive, quantitative, colorimetric, and fluorometric sensing of hydrazine in DMF/water, 4:3 (v:v) ratio. The basic nature of hydrazine is an idyllic analyte and can be predicted to bind with the receptor CPR. Remarkably, as synthesized compound, CPR displays excellent structures of bluish-green emission, large Stokes shift, rapid emissive response to hydrazine (120 s), and good photophysical nature. Additionally, the addition of hydrazine in incremental quantities to CPR results in considerable emission quenching of about 92.3%, which modifies the colorimetric features of CPR. The smartphone-assisted red, green, and blue (RGB) values-based colorimetric sensing techniques were made to follow the colorimetric changing behavior of CPR with hydrazine. Most crucially, this technique was also used to keep track of real water samples containing hydrazine, such as tap water and drinking water samples.

A unique triple–channel fluorescent probe for discriminative detection of cyanide, hydrazine, and hypochlorite

Herein, the first triple-channel fluorescent probe, TTB, excited at the same wavelength (λex = 360 nm) in the same sensing medium for the detection and discrimination of cyanide, hydrazine, and hypochlorite, is disclosed. While a fluorescent white color appeared (λem = 470 nm) with the addition of cyanide ion into the probe solution, upon addition of hydrazine and hypochlorite, green (λem = 503 nm) and orange (λem = 585 nm) fluorescent colors, respectively, were observed. A naked-eye detection for the three ions was documented. With the appearance of orange color, a mega Stokes shift of 175 nm was observed. The probe exhibited excellent selectivity and lower detection limits of 0.24 μM, 4.1 nM and 0.27 μM, and dynamic ranges of 0.0–2.0 μM, 0.0–0.05 μM and 0.0–2.0 μM for cyanide, hydrazine and hypochlorite, respectively. The sensing mechanism was investigated through computational studies before and after the addition of cyanide, hypochlorite, and hydrazine, applying density functional theory (DFT), along with the calculation of optical properties by time-dependent DFT (TD-DFT) method. The results were found to be in good agreement with the experimental values. Remarkably, the probe, TTB, successfully detected cyanide, hydrazine, and hypochlorite in complex water samples. Moreover, the detection of cyanide was successfully performed in apricot kernels, as well as hypochlorite in fruits and vegetables.

An Integrated Approach for the Recovery of Sn from Used Water Adsorbents

This research examined a scenario for the recovery of a high-capacity Cr(VI) adsorbent, consisting of Sn6O4(OH)4, after reaching its operational lifetime. To accomplish this target, a sequence of processes involving the spent adsorbent’s decomposition, the separation of Sn/Cr ions, and Sn6O4(OH)4 reconstruction was investigated. Characterization of the saturated adsorbent indicated its extended oxidation to SnO2 during its use according to the occurring Cr(VI) to Cr(III) reduction mechanism, which is responsible for the loading of 19 mg Cr/g. To decompose saturated adsorbent, the optimized process involved the dissolution by HCl using a solid concentration of 10 g/L, a solid to acid mass proportion of 1:20, an increase of the temperature at 75 °C. Such conditions brought a dissolution rate of more than 95% and 92.5%, respectively, of the total Sn and Cr in the spent adsorbent. Then, separation of Cr was succeeded by the addition of hydrazine, which acts as a reducing agent for the transformation of Sn(IV) to Sn(II); the precipitation of Cr(III) at pH 3, and the reconstruction of Sn6O4(OH)4 in a second step after increasing pH to 7. The recovered adsorbent stabilized a higher percentage of Sn(II) than the initial material, which explains the improvement of the removal efficiency by 50% in the Cr(VI) adsorption capacity.

Multistimuli-Responsive Chromism of Vinylene-Linked Bisflavin Based on the Aggregation and Redox Properties.

Multistimuli-responsive chromism was observed for vinylene-linked bisflavin 1 a with an extended π-conjugated platform. The yellow emission of a dilute solution of 1 a in CHCl3 (0.2 mM) observed at 298 K under UV excitation was changed to orange or red emission upon (1) an increase of concentration, (2) a decrease of temperature, and (3) variation of the solvent. This is in contrast to the almost non stimuli-responsive chromism of the N-methylated bisflavin analogue 1 b and monoflavin 2 a. Mechanistic investigation by 1 H NMR analysis under various conditions revealed that the extended π-conjugation platform and imide moiety of 1 a generate controllability in the formation of lower- and higher-ordered aggregates, which induce variation of the emission color upon change. Bisflavin 1 a also exhibited redox-induced chromism, where the orange emission of 1 a was quenched by the addition of hydrazine under anaerobic conditions, and changed back to the original emission upon subsequent bubbling of O2 gas.

One pot synthesis of 4,5-dibromo-3,6-diarylpyridazine from 1,4-diarylbuta-1,3-diyne

Pyridazines are an important scaffold present in various pharmacophores due to their significant physiochemical features of drug molecules. Laboratory synthesis of pyridazines is highly important because their natural sources are very rare. A one-pot two-step methodology has been developed for the synthesis of 4,5-dibromo-3,6-diarylpyridazines starting from easily available starting material 1,4-diarylbuta-1,3-diynes. The reaction goes through the electrophilic addition of Br+ ion with alkyne bonds followed by nucleophilic addition of hydrazine and then intramolecular cyclization.

Luminescent “Chugaev-type” cyclometalated iridium(III) complexes synthesized by nucleophilic addition of hydrazine

In this work, we describe a series of six neutral Chugaev-type chelating dicarbene iridium complexes with different cyclometalating ligands. The effects of different cyclometalating ligands on the emission properties of dicarbene iridium complexes are evaluated. The triazole- and NHC-derived cyclometalating ligands combine with the strong σ–donating Chugaev-type dicarbene ligand, resulting in phosphorescence that is blue-shifted compared to previously described analogues. The complexes are synthesized by the nucleophilic addition of hydrazine to cationic bis-isocyanide iridium complexes, characterized by 1H, 13C{1H}, and 19F NMR spectroscopy as well as high-resolution mass spectrometry. Four of the six molecular structures of the dicarbene complexes were determined by X-ray crystallography. Electrochemical properties of the compounds were evaluated by cyclic voltammetry analysis, which provides evidence that the HOMO and LUMO energies are dependent on the cyclometalating ligands employed. All the Chugaev-type iridium complexes exhibit blue to blue-green phosphorescence in solution at 77 K and all but one in poly(methyl methacrylate) (PMMA) thin films at room temperature. Although the quantum yields for all the complexes are modest, we succeeded in blue-shifting the emission wavelength of these dicarbene-type iridium complexes.

Regulating electronic structure by Mn doping for nickel cobalt hydroxide nanosheets/carbon nanotube to promote oxygen evolution reaction and oxidation of urea and hydrazine

Electrocatalytic water splitting is one of the direct and efficient means to yield high-purity hydrogen, but it still exists some challenges in addition to the sluggish anodic oxygen evolution reaction (OER). Constructing highly-efficient electrocatalysts with superior properties plays an essential role in industrial hydrogen production. In this work, a novel electrocatalyst with a distinctive three-dimensional (3D) structure is constructed by intertwining two-dimensional (2D) hexagonal NiCo hydroxide nanosheets (NiCo HNS) with one-dimensional (1D) carbon nanotubes (CNTs). The strategy of elemental doping engineering is employed to further enhance the catalytic performance. The as-fabricated composite of Mn-doped nickel cobalt hydroxide nanosheets intertwined with CNTs (1.5Mn-NiCo HNS/CNT) delivers superior OER electrocatalytic performance, which requires an overpotential of only 239 mV to achieve the current density of 10 mA cm−2 in 1 M KOH. Compared to NiCo HNS/CNT, the 1.5Mn-NiCo HNS/CNT electrocatalyst exhibits characteristics of improved electrical conductivity, larger electrochemical active surface area (ECSA), and faster reaction kinetics due to Mn doping. Density functional theory (DFT) calculations revealed that the adsorption of OH– during the first step of OER process was the potential determining step for the Mn substituted Co sites, and the Mn substituted Co sites were the optimum reactive sites that determined the OER performance of the 1.5Mn-NiCo HNS/CNT. Mn doping was proved beneficial to optimize the reaction path and decrease the reaction kinetics energy barrier. The addition of urea or hydrazine into the electrolyte directly decreases the energy consumption and realize their decomposition as pollutants in industrial and agricultural wastewater.

Corrosion inhibition of hydrazine on carbon steel in water solutions with different pH adjusted by ammonia

Abstract The ammonia-hydrazine shutdown protection method is widely used in thermal power plants in China because of its good protective performance. However, the toxicity and safety of hydrazine have restricted its use in many power plants, and it is necessary to improve the shutdown protection techniques. In this paper, electrochemical impedance spectroscopy and potentiodynamic polarization curves were used to study the effect of hydrazine in water solutions of different pH values, adjusted with ammonia on the corrosion behavior of carbon steel. It was found that in the water solution without hydrazine, the corrosion resistance of a carbon steel electrode increased with raising the pH. When the pH value of water increased to 10.5, the impedance value of the carbon steel increased significantly, the corrosion current density decreased from 26.06 μA·cm−2 at pH 10.0 to 2.36 μA·cm−2, and the steel surface was passivated. Hydrazine had different effects on the electrochemical corrosion behavior of carbon steel in water solutions with various pH. When the pH of water was not higher than 10.0, hydrazine had a good corrosion inhibition effect on carbon steel. When the pH of water was not lower than 10.5, the addition of hydrazine inhibited the passivation of carbon steel and promoted the corrosion. The adsorption and substitutional oxidation of hydrazine in the anode region of carbon steel surface should be the reasons for the above phenomenon.

A Graphene Oxide-based Covalent Resorufin-Conjugated Fluorescence "OFF-ON" Probe for Detection of Hydrazine.

The unique properties of graphene oxide (GO), such as good water solubility, non-toxicity, biocompatibility and cell permeability, make GO well suited for a number of biological applications. In this study, we explore the application of GO as an efficient fluorescent quencher for a highly fluorescent organic dye, resorufin (RF). The quenching effect of GO on resorufin is studied by noncovalent and covalent bonding of resorufin, respectively. The fluorescence is completely quenched when resorufin is covalently linked to GO; while resorufin's fluorescence could be still observed through noncovalent bonding to GO sheet. Interestingly, addition of hydrazine into RF-GO complex causes the fluorescence recovered, providing a potential ''OFF-ON'' fluorescence responsive probe for detecting hydrazine in vitro and in living cells.

Evaluation of long-term preservation and reactivation efficiency of anaerobic ammonium oxidation (anammox) microorganisms based on activation energy

The preservation efficiency of mainstream (M−ANA) and sidestream anaerobic ammonium oxidation (anammox) (S-ANA) were evaluated based on their activation energy (Ea). The Ea of M−ANA cultivated under low nitrogen loads was lower than that of S-ANA, which greatly contributed to enhancing the viability of anammox during preservation at 4 °C. After preservation for 140 d, the decay rate (bAN) of M−ANA ranged from 0.0012 to 0.0013/d; the bAN of S-ANA was 0.0036–0.0041/d. The addition of hydrazine, which requires minimal energy to activate anammox metabolism, is highly beneficial for the viability of microorganisms. The low Ea of anammox contributes to efficient reactivation with rapid reactivation of heme c, and the addition of hydrazine makes the process more beneficial. Although the specific nitrogen removal rate of the M−SNA seed sludge was much lower than that of S-ANA, the rate of M−ANA became higher after 48 days of reactivation.

Anti Hemolytic Activity of Rutin incase of Phenyl Hydrazine induced Hemolysis

The important role of Red Blood Cells (RBCs) is to transport oxygen to the tissues from the lungs to provide oxygen to all cells. During circulation, RBCs are continuously exposed to both endogenous and exogenous sources of reactive oxygen species (ROS) that can injury the RBC and ruin its function. The imbalance between cellular production of reactive oxygen species and the counteracting antioxidant mechanism leads to Oxidative stress. Flavonoids are low molecular weight secondary polyphenolic metabolites present in plants characterized by their flavan nucleus. Rutin is a flavonol plentiful in a variety of commonly ingested foods. The term ‘Rutin’ came from a plant known as Ruta graveolens that also encompasses Rutin. Teas and fruits have high concentration of Rutin. Buckwheat seeds (Fagopyrum esculantum) are the richest source. Rutin protects the body from cellular damage caused by free radicals with its antioxidant properties. It helps to eliminate cholesterol from the body and increase elasticity of the arterial walls, which in turn promotes greater blood flow. The present investigation was aimed to assess the antihemolytic activity of the Rutin using phenyl hydrazine as hemolysin. This study uses RBC as model system to access the anti-hemolytic activity of Rutin using phenyl hydrazine as hemolysin. Phenyl hydrazine which was used previously in treating sickle cell anemia was used in this investigation as hemolysin. The result of the study shows that the addition of phenyl hydrazine [1-500 μg/ml] to the RBC suspension caused significant (P<0.01) rise in hemolysis. The cell pellet in the bottom of the tubes reduced to reddish colored supernatant indicating hemolysis. The effect was concentration dependent. The present investigation clearly indicates that phenyl hydrazine causes hemolysis and toxicity to RBC. The concurrent addition of phenyl hydrazine along with the test compound Rutin (100-500 μg/ml) to the RBC suspension significantly (P<0.01) reduced phenyl hydrazine induced hemolysis in a concentration dependent manner. The protective effect of Rutin on the hemolysis induced by phenyl hydrazine clearly shows it acts as anti-hemolytic agent. This finding was compared with the standard ascorbic acid. IC50 value of Rutin and ascorbic acid were 160.86 and 163.5 μg/ml respectively. The Rutin extract showed maximum inhibitory effect 69.8%.at 500μg/ml. This shows that Rutin can be effectively used as anti-hemolytic agent.

A sensitive electrochemical detection of hydrazine based on SnO2/CeO2 nanostructured oxide

In this study, a SnO2/CeO2 nanostructured oxide was prepared by a sonication-based approach. The prepared SnO2/CeO2 nanostructured oxide was examined for its structural and morphological characteristics using powder X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, X-ray electron microscopy, and Brunauer–Emmett–Teller analysis. An electrochemical sensor was fabricated by deposition of the SnO2/CeO2 nanostructured oxide on a glassy carbon electrode (GCE) using a binder (SnO2/CeO2/GCE). The fabricated SnO2/CeO2/GCE, as an efficient electrochemical sensor, was employed for detection of hydrazine using the electrochemical technique viz. linear sweep voltammetry (LSV). The voltammetric detection of hydrazine at the SnO2/CeO2/GCE sensor exhibits a rapid increase in the oxidation peak current upon addition of hydrazine. The electrochemical response of the SnO2/CeO2/GCE shows excellent sensitivity for hydrazine. The sensitivity, limit of detection (LOD), and limit of quantification (LOQ) of the sensor using LSV technique are estimated to be 81μAμM−1cm−2, 0.179 μM, and 0.52 μM, respectively. The SnO2/CeO2/GCE as a sensor shows a mostly linear relationship between currentandconcentration of hydrazine over the concentration range of 3–26 μM (R2 = 0.975). Overall, our proposed SnO2/CeO2/GCE sensor shows significant stability, selectivity, sensitivity, repeatability, and reproducibility.

Electroless Plating of High-Performance Composite Pd Membranes with EDTA-Free Bath.

High-performance composite Pd membranes were successfully fabricated using electroless plating with an EDTA-free bath. The plating started with employing the one-time addition of hydrazine. In the experiment, the hydrazine concentrations and plating bath volumes were systematically varied to optimize the plating. The optimum composite Pd membrane tube showed high H2 permeance of 4.4 × 10−3 mol/m2 s Pa0.5 and high selectivity of 1.6 × 104, but poor cycling stability. Then, a method of sequential addition of the hydrazine from the high to low concentrations was employed. The resultant membrane, about 6 μm thick, still exhibited a high selectivity of 6.8 × 104 as well as a much-improved plating yield and cycling stability level; this membrane outperformed the membrane made using the unmodified plating technique with the EDTA-contained bath. This result indicates the EDTA-free bath combined with the sequential addition of hydrazine is a simple, low-cost, yet effective method for preparing thin, dense composite Pd membranes featuring high hydrogen permeation flux and high thermal durability.