Nitro Research Articles

Edge-Confined Rh2/MoS2 Dual-Atom Catalyst for Selective Activation of Nitro Group to Amino Group at Room Temperature

Edge-Confined Rh₂/MoS₂ Dual-Atom Catalyst for Selective Activation of Nitro Group to Amino Group at Room Temperature

Computational Study of Aminoglycoside and Fluoroquinolone Antibiotics

Molecular Docking has become an important component of the drug discovery process. Since first being developed in the 1980s, advancements in the power of computer hardware and the increasing number of and ease of access to small molecule and protein structures have contributed to the development of improved methods, making docking more popular in both industrial and academic settings. In this research Molecular Docking performed on Ciprofloxacin and Streptomycin by using Auto dock and Discovery Studio Software. QSAR study revealed that substitution of different electron donating or withdrawing group at different position on Ciprofloxacin and Streptomycin. Lead nucleus elaborate change in pharmacological activity. Molecular docking done by substituting or replacing different group at different position affected the potency of drug. On addition of methyl and nitro group decreases the activity of Ciprofloxacin while replacement of Guanidino groups from streptidine ringincreases its antibiotic activity.

Edifice of metal stannate as nano-catalyst: An ultra-sensitive and highly selective enhanced electrochemical sensing of chloronitrobenzene

Metal stannate is recognized as an effective electrocatalyst in the electrochemical sensor field. In this case, the simple co-precipitation method was used to produce Zn2SnO4. A range of microscopic and spectroscopic techniques were employed to describe the physicochemical properties of synthesized materials. In a modified glassy carbon electrode (GCE), the electrochemical performance of Zn2SnO4 was investigated using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) in a three-electrode setup. When reducing 1-chloro-4-nitrobenzene (CNB), Zn2SnO4/GCE exhibits strong electrochemical activity, showing a lower peak potential and a larger cathodic peak current than when GCE is used alone. With a sensitivity of 7.2 nM at the lower detection limit, the linear range response ranges from 0.04 to 360.21 µM. Furthermore, when tested with aromatic nitro groups, inorganic species, and antibiotic therapies, the modified electrode shows good storage stability, reproducibility, repeatability, and interference study capabilities. Zn2SnO4/GCE also demonstrates better electrochemical sensitivity for the detection of CNB. The synthesized Zn2SnO4/GCE exhibits remarkable practical ability to identify CNB in water samples with sufficient yield. This is the first report we are aware of regarding Zn2SnO4/GCE studies of electrochemical sensing towards CNB.

Cascade Cyclization of N-Cyanamide Alkenes for the Divergent Synthesis of Azido-, Nitro-, and Alkenyl-Containing Pyrroloquinazolinones.

Radical cascade cyclizations of N-cyanamide alkenes have been developed for the divergent synthesis of pyrroloquinazolinones bearing azido, alkenyl, and nitro groups by controlling the reaction conditions. The reaction temperature and the loading of the base play important roles in the different reaction pathways. These reactions are characterized by wide functional group compatibility and mild conditions.

Magnesium nitrate-tricine nanoparticles: Temperature impact to enhancing third order optical nonlinearity

Nano-hybrid promoted as materials with improved optical properties. The aim of this study was to analyze differences in optical properties at micro-scale. This research focuses on the impact of reaction temperature during the creation of magnesium nitrate-tricine nanoparticles through chemical vapor deposition. The study investigates how temperatures of 200°C and 300°C affect the particle size, crystallinity, and morphology of the nanoparticles. Optimizing these properties is essential for achieving the desired third-order NLO effect. By understanding the influence of temperature on nanoparticle characteristics, researchers can develop more effective NLO materials for future photonic devices. This study explores the chemical and structural differences between MNT 300 and MNT 400 materials using various techniques. Spectroscopic analysis reveals similarities in both materials with a shared peak at 1400 cm−1. However, MNT 400 exhibits additional peaks suggesting the presence of aromatic rings, nitro compounds, or variations in N–H bonds. Both MNT 300 and MNT 400 exhibit micro porous behaviour with a narrow pore size distribution around 14 nm to 15 nm, indicating tightly packed structures. Transmission Electron Microscopy analysis shows a wide particle size range (2 nm to 200 nm) in both materials, suggesting the presence of atomic clusters, individual molecules, and potentially agglomerated structures. FT-Raman spectroscopy reveals higher intensity peaks in MNT 400, which could be due to a higher concentration of specific bonds, a more ordered structure, or enhanced Raman scattering. This suggests greater crystallinity or molecular uniformity in MNT 400 compared to MNT 300.

Transmission of substituent effects in para-disubstituted benzenes: 13C chemical shift and Mulliken charge modeling of para carbon atoms via the Reynolds DSP model

The PM3 calculations of the Mulliken charge and the experimental 13C substituent chemical shifts (SCS) of para carbon for 17 para-disubstituted benzene series were investigated by correlation analysis. A significant correlation between the charge and the 13C SCS of the para carbon of the same series was observed. In mono-substituted benzene, the correlation of para13C SCS with Mulliken charges calculated by PM3 and Mulliken charge calculated by DFT(B3LYP) with basis set 6 311(dp)G of the same carbon is similar. All the substituent effects on the charge and 13C SCS were modeled by the Reynolds’ dual substituent parameter model (charge or 13C SCS = ρF σF + ρRσRo), where σF and σRo are the Reynolds’ field and resonance constants, respectively, and ρF and ρR are the field and resonance effects, respectively. The coefficients of determination for all series were significant. The concept of π-polarization was used to analyze variation in ρF. The interpretation of ρF showed parallels between the charge and 13C SCS. An enhanced ρF for a given series was attributed to the stabilization of the π-polarization charge at the para carbon. The ρR was a function of extended conjugation within the side chain. Parallelism of charge and 13C SCS of the ρR of the compared series were also observed, except in series with the reverse-substituent effect and the possession of a strong electronegative group, such as a nitro or azo group.

Design and synthesis of a 2,5-Diarylthiophene chromophore for enhanced near-infrared two-photon uncaging efficiency of calcium ions

The design and synthesis of two-photon-responsive chromophores have recently garnered significant attention owing to their potential applications in materials and life sciences. In this study, a novel π-conjugated system, 2-dimethylaminophenyl-5-nitrophenylthiophene derivatives, featuring a thiophene unit as the π-linker between the donor (NMe2C6H4–) and acceptor (NO2C6H4–) units was designed, synthesized, and applied for the development of two-photon-responsive chromophores as a photoremovable protecting group in the near-infrared region. Notably, the positional effect of the nitro group (NO2), meta versus para position, was observed in the uncaging process of benzoic acid. Additionally, while the para-isomer exhibited a single fluorescence peak, a dual emission was detected for the meta-isomer in polar solvents. The caged calcium ion (Ca2+) incorporating the newly synthesized thiophene unit exhibited a sizable two-photon absorption cross-section value (σ2 = 129 GM at 830 nm). Both one-photon and two-photon photoirradiation of caged calcium ions successfully released calcium ions, indicating the potential utility of 2,5-diarylthiophene derivatives in future biological studies.Graphical abstract

A multipurpose organometallic pyridyl Schiff base-modified poly(divinylbenzene) matrix for the catalytic removal of nitrophenols and polycyclic pollutants

Widespread organic pollutants in wastewater include toxic nitrophenols and polycyclic molecules. Here, we aim to develop a single multipurpose catalyst capable of degrading these structurally dissimilar contaminants by preparing a pyridyl Schiff base-functionalized poly(divinylbenzene) porous organic polymer displaying Ag complexes (PDVB-PA@Ag). PDVB-PA@Ag hydrogenated 4-nitrophenol (4-NP) efficiently to valuable and less toxic 4-aminophenol with an optimized reaction rate of 45.4 × 10−3 s−1 and apparent activation energy of only 20.1 kJ mol−1. The same catalyst also readily hydrogenated the isomers of 4-NP as well as nitrophenols with several nitro groups and halogenated nitrophenols with reaction rates ranging from 4.0 to 20.3 × 10−3 s−1. In addition, the multiuse PDVB-PA@Ag was capable of carrying out a second type of reaction and degraded multiple polycyclic dyes commonly found in wastewater including auramine O, basic blue 17, aniline blue, and malachite green through Fenton-like oxidation. PDVB-PA@Ag-based degradation processes for the four toxic dyes evaluated were efficient with pseudo-first order reaction rates varying between 1.2 × 10−2 to 3.7 × 10−2 min−1. By coordinating an array of versatile catalytic complexes on an extensive and stable porous support, PDVB-PA@Ag was made highly performant at completing different essential water-cleaning processes.

Continuous synthesis of metal oxide‐supported high‐entropy alloy nanoparticles with remarkable durability and catalytic activity in the hydrogen reduction reaction

AbstractMetal oxide‐supported multielement alloy nanoparticles are very promising as highly efficient and cost‐effective catalysts with a virtually unlimited compositional space. However, controllable synthesis of ultrasmall multielement alloy nanoparticles (us‐MEA‐NPs) supported on porous metal oxides with a homogeneous elemental distribution and good catalytic stability during long‐term operation is extremely challenging due to their oxidation and strong immiscibility. As a proof of concept that such synthesis can be realized, this work presents a general “bottom‐up” l ultrasonic‐assisted, simultaneous electro‐oxidation–reduction‐precipitation strategy for alloying dissimilar elements into single NPs on a porous support. One characteristic of this technique is uniform mixing, which results from simultaneous rapid thermal decomposition and reduction and leads to multielement liquid droplet solidification without aggregation. This process was achieved through a synergistic combination of enhanced electrochemical and plasma‐chemical phenomena at the metal–electrolyte interface (electron energy of 0.3–1.38 eV at a peak temperature of 3000 K reached within seconds at a rate of ~105 K per second) in an aqueous solution under an ultrasonic field (40 kHz). Illustrating the effectiveness of this approach, the CuAgNiFeCoRuMn@MgO‐P3000 catalyst exhibited exceptional catalytic efficiency in selective hydrogenation of nitro compounds, with over 99% chemoselectivity and nearly 100% conversion within 60 s and no decrease in catalytic activity even after 40 cycles (>98% conversion in 120 s). Our results provide an effective, transferable method for rationally designing supported MEA‐NP catalysts at the atomic level and pave the way for a wide variety of catalytic reactions.image

Aerobic Copper-Catalyzed Oxysulfonylation of Vinylarenes with Sodium Sulfinates under Mild Conditions: A Modular Synthesis of β-Ketosulfones.

An aerobic copper-catalyzed oxysulfonylation of vinylarenes with sodium sulfinates is described. This protocol features mild reaction conditions, convenient operation, and broad substrate scope with respect to vinylarenes and sodium sulfinates. Notably, the protocol demonstrates excellent tolerance of functional groups such as chloro, bromo, ester, cyano, and nitro groups. Mechanistic investigations indicated that the reaction should undergo radical cascades involving a sulfonyl radical generated from sodium sulfinate with air as the terminal oxidant, addition across alkene to deliver a benzylic radical, and subsequent cross-coupling with air.

Synthesis of Dihalonaphthalenes via Silver-Catalyzed Halogenation and Electrophilic Cyclization of Terminal Alkynols.

Herein, we report a silver-catalyzed halogenation and electrophilic cyclization reaction based on the trifunctionalization of terminal alkynols with NBS or iodine monochloride in a step-efficient synthetic way to produce homo/heterodihalogenated naphthalene derivatives bearing two different halogen atoms in moderate to good yields. This methodology readily accommodates various functional groups, including electron-withdrawing nitro, cyano, acid-sensitive dioxazolyl, and alkoxy groups.

Cycloadditions of 4-Alkenyl-2-aminothiazoles with Nitroalkenes in the Formal Synthesis of Pramipexole: An Experimental and Computational Study.

4-Alkenyl-2-dialkylaminothiazoles act as in-out dienes in [4 + 2] cycloaddition reactions with nitroalkenes, furnishing 2-amino-6-nitro-4,5,6,7-tetrahydrobenzothiazoles in moderate to good yields, accompanied by a subsequent 1,3-H migration. These transformations proceed with exquisite site-, regio-, and diastereoselectivity. This strategy is further enriched by revealing a novel route for pramipexole synthesis. The examination of the potential energy surfaces associated with the four possible reaction pathways for the Diels-Alder cycloaddition (relative approach of the diene-dienophile and endo/exo approach of the nitro group) not only aligns with experimental observations but also unveils key mechanistic insights. Specifically, computational analyses uncover the favored pathway yielding 6-nitro-4,5,6,7-tetrahydrobenzothiazoles, with some instances proceeding through a two-step mechanism involving a tandem sequence of chemical processes, and the influence of various factors such as dienophile structure and the approach mode of the nitro group. Additionally, the stabilization of the exo-transition states, particularly facilitated by phenyl substitution in the dienophile, is highlighted. Asynchronicity, dipole moment, and other parameters indicative of polar character further characterize these Diels-Alder reactions. Conceptual DFT calculations underscore the pivotal role of the 1,3-thiazole ring in enhancing dienic activation and dictating regioselectivity, emphasizing interactions between the C5 of the thiazole nucleus and the Cβ atom of the nitroalkenes.

Single-Atom Co-N4 Sites Mediate C=N Formation via Reductive Coupling of Nitroarenes with Alcohols.

It remains challenging to construct C=N bonds due to their facile hydrogenation. Herein, a single Co atom catalyst was discovered to be active for the selective construction of C=N bonds toward the synthesis of imines and N-heterocycles via reductive coupling of nitroarenes with various alcohols, including inert aliphatic ones. DFT calculations and experimental data revealed that the transfer hydrogenation proceeded via the intramolecular hydride transfer and the transfer of H from the α-Csp3-H bond to the nitro group was the rate-determining step. The single Co atoms served as a bridge to transfer the electrons from the catalyst to the adsorbed alcohol molecules, resulting in the activation of the α-Csp3-H bond. Unlike metal nanoparticles, the C=N bonds in imine products can be reserved due to the large steric hindrance from substituents on C and N. DFT calculation also confirmed that transfer hydrogenation of the C=N bonds in imines is thermodynamically unfavored with a much higher energy barrier compared with the transfer hydrogenation of the -NO2 group (1.47 vs 1.15 eV).

Substitution Effects on Subcellular Organelle Localization in Live-cell Imaging.

A series of D-π-A indole-containing fluorescent probes were developed, followed by an investigation of their photophysical properties and compounds' suitability for subcellular imaging in living cells. We demonstrate that the preference for mitochondrial localization was lost when morpholine was substituted, resulting in the accumulation of the molecule in the lysosomes. However, interestingly, the presence of a nitro group led to their localization within the lipid droplets despite the presence of the morpholine pendant. We also showcase the probes' sensitivity to pH, the influence of added chloroquine, and the temperature response on the changes in fluorescence intensity within lysosomes. The design of the probes with strong intramolecular charge transfer and substantial Stokes shift could facilitate extensive application in various cellular lysosomal models and contribute to a better understanding of the mechanisms involved in stimuli-responsive diseases.

Tuning the Thermal Stability of Tetra-o-chloroazobenzene Derivatives by Transforming Push-Pull to Push-Push Systems.

Molecular photoswitches provide interesting tools to reversibly control various biological functions with light. Thanks to its small size and easy introduction into the biomolecules, azobenzene derivatives have been widely employed in the field of photopharmacology. All visible-light switchable azobenzenes with controllable thermostability are highly demanded. Based on the reported tetra-o-chloroazobenzenes, we synthesized push-pull systems, by introducing dialkyl amine and nitro groups as strong electron-donating and electron-withdrawing groups on the para-positions, and then transformed to push-push systems by a simple reduction step. The developed push-pull and push-push tetra-o-chloroazobenzene derivatives displayed excellent photoswitching properties, as previously reported. The half-life of the Z-isomers can be tuned from milliseconds for the push-pull system to several hours for the push-push system. The n-π* and π-π* transitions have better resolution in the push-push molecules, and excitation at different wavelengths can tune the E/Z ratio at the photostationary state. For one push-pull molecule, structure and absorption spectra obtained from theoretical calculations are compared with experimental data, along with data on the push-push counterpart.

Bucking the trend: gathering 12 nitro groups towards an ultrahigh-energy oxidizer with superior stability

Bucking the trend: gathering 12 nitro groups towards an ultrahigh-energy oxidizer with superior stability

Long cycle life aqueous zinc-ion battery enabled by a ZIF-N protective layer with electron-withdrawing group and zincophilicity on the Zn anode

Aqueous zinc-ion batteries (AZIBs) have garnered attention from researchers for their high theoretical capacity, safety, and low cost. However, the uncontrolled growth of zinc (Zn) dendrites and spontaneous corrosion reactions on the Zn anode significantly compromise the cycle life of AZIBs. This paper proposes the utilization of a novel zeolitic imidazole framework (ZIF-N) material with zincophilicity and hydrophilicity for modifying the Zn anode of AZIBs. ZIF-N incorporates numerous electron-withdrawing nitro groups at the Zn/ZIF-N interface to regulate the uneven electron distribution on the Zn anode. The modified Zn anode (Zn@ZIF-N) exhibits a lower polarization ratio (32.18 mV at 4 mA cm−2) and an extended cycle life (over 700 h at 4 mA cm−2). At a current density of 1 mA cm−2, the battery composed of a Zn@ZIF-N anode and NVO (NaV3O8) achieves a cycle life of 1600 cycles. This work provides a straightforward and cost-effective strategy for modifying the Zn anode to prolong the cycle life of AZIBs.

The Electrochemistry of Nitro Compounds from a Bibliometric Approach

The heterocyclic and aromatic nitro compounds are industrially and commercially important chemicals, used in drugs, explosives, pesticides, and dyes. Despite their economic importance, the advent of these chemicals also brought serious human health and environmental problems due to their toxic characteristics as contaminants and pollutants. The nitro group is catalyzed in vivo by nitroreductases promoting a six-electron reduction to form sequentially the nitro radical anion, nitroso-, N-hydroxylamino and amino-functional groups. These reactions can be electrochemically reproduced, involving the development of analytical methods and electrochemical sensors, degradation and removal of organic compounds in effluents, corrosion studies, and studies of action mechanism of drugs on DNA bases. In this sense, a bibliometric analysis has been performed based on the Web of Science Core Collection in conjunction with VOSviewer software for generating network visualizations. This research covered the database until 2023, describing the main research areas and the annual publication trends, the collaborations and contributions among countries and research institutions, in addition to identifying the most cited articles, hotspots, and the analysis of evolution and relevance of keywords. This investigation made it possible to recognize the main research focuses and what is under development, providing a comprehensive overview on electrochemistry of nitro compounds.

Identification of 5-aminometonitazene and 5-acetamidometonitazene in a postmortem case: are nitro-nitazenes unstable?

In recent years, the use of 2-benzylbenzimidazole opioids ('nitazenes') has increased with them becoming one of the most prominent synthetic opioid subclasses of novel psychoactive substances. With the increased prevalence, there is also a concern of the dangers to public health with the use of nitazenes due to their high potency especially with polypharmacy. To aid in the detection of such compounds, it is important that forensic toxicology laboratories maintain up-to-date compound libraries for drug screening methods and that sensitive analytical instrumentation is available to detect the low blood/plasma concentrations of more potent drugs. This includes not only the compounds themselves but also potential metabolites and/or degradation products. Metonitazene is a 'nitro-nitazene' with a nitro group at position 5 of the benzimidazole ring. As a nitro-nitazene, there is a potential for bacterial degradation of metonitazene to 5-aminometonitazene, as occurs with nitro-benzodiazepines. In this study, we provide evidence from a postmortem (PM) case of degradation of metonitazene in unpreserved PM blood using liquid chromatography-triple quadrupole mass spectrometry (LC-QQQ-MS), and putative identification of the degradation/metabolic products 5-aminometonitazene and 5-acetamidometonitazene by liquid chromatography-quadrupole time-of-flight mass spectrometry. The results from LC-QQQ-MS analysis indicated that there did not appear to be such degradation in preserved (fluoride/oxalate) blood. These results suggest that nitro-nitazenes may be subject to similar in vitro stability/degradation issues as nitro-benzodiazepines. These breakdown products should be added to instrument libraries to aid in the detection of the use of nitro-nitazenes, and nitro-nitazenes should be quantified in preserved blood samples where available.

Advanced doping method for highly conductive CNT fibers with enhanced thermal stability

Abstract Due to the inherent limitations of metals, such as their poor performance at high temperatures caused by thermo-oxidation and expansion, carbon nanotube yarns (CNTFs) have emerged as promising alternatives because of their high electrical conductivity and thermal stability. Doping of CNTFs has been widely studied because it significantly increases electrical conductivity through a simple process. Despite these advantages, doped CNTFs are not suitable for extreme environments, especially high temperatures. This is due to the weak interaction between dopants and CNTFs, along with the low thermal stability of the dopants themselves, leading to dopant decomposition and oxidation at high temperatures. Herein, we present doped CNTFs that are covalently functionalized with a nitrogen compound composed of imide and nitro groups, which are renowned for good thermal stability. The electron-withdrawing effect of this nitrogen compound polarizes the CNTFs to a positive charge, inducing p-type doping effects and enhancing electrical conductivity from 2989 to 4008 S cm−1. The strong covalent bonding between the nitrogen compound and CNTFs, along with the thermal stability of the dopants, ensures that the electrical conductivity of our doped CNTFs is maintained even after annealing at 300 °C for 12 h. Our proposed doped CNTFs offer a guideline for expanding the practical applications of doped CNTFs to a wider range of high-temperature environments.