Cyanide Research Articles

At least five: Benefit origins of potassium and sodium co-doping on carbon nitride for integrating pharmaceuticals degradation and hydrogen peroxide production

Benefit origins of potassium (K+) and sodium (Na+) co-doping on carbon nitride for integrating pharmaceutical degradation and hydrogen peroxide (H2O2) production was investigated. K+ and Na+ co-doped carbon nitride (CN-K/Na) with modified crystallinity and surface structure was synthesized by ionothermal polymerization of urea. The CN-K/Na exhibited an apparent quantum yield of 26.2% in H2O2 photosynthesis at 400nm (isopropanol as proton donor), and it was better at extracting proton from pharmaceutical-laden wastewater to produce H2O2 than pristine carbon nitride. These superior performances are attributed to the benefits directly or indirectly caused by the co-doping: i) Na+ optimizes in-plane charge transfer, ii) K+ builds channel for interplane charge transfer, iii) cyano group as Lewis acid site adsorbs and activates oxygen, iv) amino group as Lewis base site extracts and releases protons, v) increased visible-light absorption. This work offers significant insights into designing polymeric photocatalysts for environmental management and energy conservation.

Cyanide profiling in stone fruit syrups: A comparative study of distillation techniques, a novel derivatization method, and cyanide composition in Maesil (Prunus Mume) syrup

Cyanide ion was derivatized with o-phthalaldehyde and 3-mercaptopropionic acid for high-performance liquid chromatography-diode array detector analysis. The structure was elucidated using nuclear magnetic resonance spectroscopy and ultra-high performance liquid chromatography coupled with triple quadrupole tandem mass spectrometry. Method validation was conducted for three distillation methods to analyze cyanogenic glycosides, cyanohydrins, and free cyanide in fruit syrup. Acid-aided distillation only detected free cyanide, while direct distillation detected both free cyanide and cyanohydrins, and enzyme-aided distillation reflected all three types. These approaches were applied to stone fruit syrups in South Korean markets and households. Among tested, maesil (Prunus mume) syrup contained the highest amount of total cyanide, reaching a maximum of 21.9 mg/kg (cyanide ion equivalent), compared to other syrups. Investigation of cyanide composition changes during maesil syrup production revealed that free cyanide occupies the lowest proportion. Cyanogenic glycosides degraded gradually during aging, while cyanohydrins remained the majority after 12 months aging.

Tunable Properties of New Cyano‐Substituent Heptahelicenes for Optoelectronic Devices: A Combined Experimental and DFT Computational Study

AbstractHere, we describe a set of coupled experimental and theoretical analyses. The introduction of one and two additional cyano groups in the carboheptahelicene backbone enhance its electron‐accepting properties. New carboheptahelicene derivatives are synthesized, and relevant characterizations of structural features, photophysical and electrochemical properties, and structure‐property relationships are described. This present work concerns the use of the density functional theory (DFT) to highlight the structural and the optoelectronic properties of carboheptahelicene derivatives and comparing the obtained findings with the experimental ones. The experimental and theoretical spectra (UV‐Vis absorption and photoluminescence) provide excellent concurrence. Afterward, molecular structures, structural parameters, molecular electrostatic potential (MEP), highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energies of frontier molecular orbitals (FMOs) are constructed. Some other optoelectronic parameter including electron affinity (EA), ionization potential (IP), and some reactive descriptor such as chemical potential (μ), global hardness (η), electronegativity (χ) and the overall electrophilicity index (ω) are determined and indicating its potential uses as an active layer in optoelectronic efficient devices. The topological methods such as electron localization function (ELF), localization orbital locator (LOL) and the reduced density gradient method (RDG) were also conducted to clarify the strengths and kinds of interactions.

Improving the curing reactivity, interfacial strength, thermal and mechanical properties of phthalonitrile resin/basalt fiber composites by reactive organic coating

Phthalonitrile (PN) resin is a thermosetting resin with excellent properties, but its poor processability hinders its wide application. Meanwhile, as a high-performance green fiber, basalt fiber (BF) shows good overall properties, but the chemical inertness and smooth surface limits its application as well. In this work, a highly reactive organic coating polydopamine (PDA) was used to promote the curing of PN resin and enhance the interfacial interaction between the polymer matrix and the fiber cloth. The successful coating of PDA was verified by SEM observation, FTIR and XPS spectra. It was found that PDA could not only increase the polarity of BF, aid the infiltration of PN resin into the fiber cloth, enhance the interfacial strength, but also promote the consumption of cyano groups and increase the chemical crosslinking density. Consequently, the overall performance of the composites was enhanced. Specifically, the laminate 0.4DABF/BAPh showed flexural strength of 447 MPa and flexural modulus of 23.3 GPa, which was 131 MPa and 4.5 GPa higher than those of BF/BAPh. The glass transition temperature of 0.4DABF/BAPh was also 77 °C higher than that of BF/BAPh.

Cyano-functionalized porous hyper-crosslinked cationic polymers for efficient preconcentration and detection of phenolic endocrine disruptors in fresh water and fish

Sensitively analyzing phenolic endocrine-disrupting chemicals (EDCs) in environmental substrates and aquatic organisms provides a significant challenge. Here, we developed a novel porous hyper-crosslinked ionic polymer bearing cyano groups (CN-HIP) as adsorbent for the highly efficient solid phase extraction (SPE) of phenolic EDCs in water and fish. The CN-HIP gave an excellent adsorption capability for targeted EDCs over a wide pH range, and the adsorption capacity was superior to that of several common commercial SPE adsorbents. The coexistence of electrostatic forces, hydrogen bond, and π-π interactions was confirmed as the main adsorption mechanism. A sensitive quantitative method was established by coupling CN-HIP based SPE method with high-performance liquid chromatography for the simultaneously determining trace bisphenol A, bisphenol F, bisphenol B and 4-tert-butylphenol in fresh water and fish. The method afforded lower detection limits (S/N = 3) (at 0.03–0.10 ng mL−1 for water and 0.8–4.0 ng g−1 for fish), high accuracy (the recovery of spiked sample at 88.0%–112 %) and high precision (the relative standard deviation < 8.5 %). This work provides a feasible method for detecting phenolic EDCs, and also opens a new perspective in developing functionalized cationic adsorbent.

Radical-triggered translocation of C-C double bond and functional group.

Multi-site functionalization of molecules provides a potent approach to accessing intricate compounds. However, simultaneous functionalization of the reactive site and the inert remote C(sp3)-H poses a formidable challenge, as chemical reactions conventionally occur at the most active site. In addition, achieving precise control over site selectivity for remote C(sp3)-H activation presents an additional hurdle. Here we report an alternative modular method for alkene difunctionalization, encompassing radical-triggered translocation of functional groups and remote C(sp3)-H desaturation via photo/cobalt dual catalysis. By systematically combining radical addition, functional group migration and cobalt-promoted hydrogen atom transfer, we successfully effectuate the translocation of the carbon-carbon double bond and another functional group with precise site selectivity and remarkable E/Z selectivity. This redox-neutral approach shows good compatibility with diverse fluoroalkyl and sulfonyl radical precursors, enabling the migration of benzoyloxy, acetoxy, formyl, cyano and heteroaryl groups. This protocol offers a resolution for the simultaneous transformation of manifold sites.

The Efficiency of Chemical and Electrochemical Coagulation Methods for Pretreatment of Wastewater from Underground Coal Gasification

This article compares chemical coagulation with electrocoagulation, two popular methods for the primary treatment of wastewater generated in the process of underground coal gasification (UCG). The primary aim was to determine which method is more effective in the removal of cyanide and sulphide ions, metals and metalloids, as well as organic compounds. In both cases, experiments were conducted in batch 1 dm3 reactors and using iron ions. Four types of coagulants were tested during the chemical coagulation study: FeCl2, FeSO4, Fe2(SO4)3, and FeCl3. In the electrocoagulation experiments, pure iron Armco steel was used to manufacture the sacrificial iron anode. Both processes were tested under a wide range of operating conditions (pH, time, Fe dose) to determine their maximum efficiency for treating UCG wastewater. It was found that, through electrocoagulation, a dose as low as 60 mg Fe/dm3 leads to &gt;60% cyanide reduction and &gt;98% sulphide removal efficiency, while for chemical coagulation, even a dose of 307 mg Fe/dm3 did not achieve more than 24% cyanide ion removal. Moreover, industrial chemical coagulants, especially when used in very high doses, can be a substantial source of cross-contamination with trace elements.

One Pot Synthesis of Alkyl Nitriles

A one-pot synthesis method to produce alkyl nitriles using the corresponding aliphatic carboxylic acid has been developed. The process involves treating the aliphatic acid with thionyl chloride to obtain the corresponding aliphatic acid chloride, which is then further treated with anhydrous ammonia gas to yield the respective aliphatic acid amide. The intermediate corresponding amide is dehydrated with thionyl chloride to obtain alkyl nitrile with a quantitative yield.

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.

Synthesis and photophysical properties of 3-aryl-2-cyanoacrylamides: Design of a turn-on fluorescent probe for cyanide ion detection

Three 3-aryl-2-cyanoacrylamide derivatives were synthesised in 71−79 % yields from cheap reagents and mild reaction conditions using the Et3N-mediated Knoevenagel condensation of fluorescent arylaldehydes (e.g., triphenylamine and anthracene) with cyanoacetamide. These dyes' photophysical properties and anions-recognizing behaviour were studied, revealing that the 9-anthracenyl derivative can "turn on" fluorescence in cyanide presence, with high selectivity and a detection limit (LOD) of 710 nM. Initially, there is fluorescence quenching by the energy transfer (ET) from the anthracene ring to the 2-cyanoacrylamide moiety due to the non-coplanarity of these fragments and, upon the cyanide addition to Cβ of the receptor unit, the intrinsic fluorescence of anthracene is restored. HRMS and NMR experiments and TD-DFT calculations were performed to confirm the detection mechanism and fluorescence properties of the design chemodosimeter; fluorescent test paper was also used to detect cyanide in an aqueous medium.

Modulating Interfacial Zn2+ Desolvation and Transport Kinetics through Coordination Interaction toward Stable Anodes in Aqueous Zn-Ion Batteries.

Aqueous Zn-ion batteries (AZIBs) are promising candidates for grid-scale energy-storage applications, but uneven Zn2+ flux distribution and undesirable water-related interfacial side reactions seriously hinder their practical application. Herein, a strategy of regulating the coordination interaction between Zn2+ and artificial interphase layers (AILs) to modulate the interfacial Zn2+ desolvation/transport behaviors and relieve side reactions for building stable Zn anodes is proposed. By selectively choosing appropriate polymers with different functional groups, it is shown that compared with the strong interaction offered by aryl groups in polystyrene-based AILs, cyano groups in polyacrylonitrile (PAN)-based AILs provide a moderate coordination interaction with Zn2+, which not only accelerates interfacial Zn2+desolvation kinetics but also enables efficient Zn2+ transport within AILs. Moreover, the Zn2+ transport kinetics of PAN-based AILs can be further enhanced with the incorporation of an ionic conductor, zinc phosphate (ZP). Because of these advantages, the Zn anodes decorated with the hybrid AILs composed of PAN and ZP can steadily operate for >2000h at 0.2mA cm-2 and >350h at a high current density of 10mA cm-2. This work provides a valuable guideline for selective design of AILs at the molecular level for durable AZIBs.

Copolymerization of novel self-promoted curing phthalonitrile with epoxy resin and its thermal property

The disadvantage of poor thermal performance of epoxy resin limits its application in special fields, therefore we improve the thermal performance of epoxy resin by copolymerizing it with phthalonitrile resin. A novel self-promoted curing phthalonitrile monomer containing pyridine rings and amino groups (APNH) was successfully synthesized using 2-amino-4-hydroxypyridine and 4-nitrophthalonitril, and characterized by FTIR and NMR spectra. DSC confirmed that the APNH monomer exhibits curing behavior that is self-promoting. Copolymerizing the APNH monomer with epoxy resin enhances the thermal performance of the epoxy resin. The curing behavior of the EPNH copolymer was studied using DSC, which revealed two distinct curing peaks. FTIR analysis showed that the EPNH copolymer has formed structures such as triazine, phthalocyanine, and isoindoline. The presence of cyano groups significantly enhances the thermal properties of the copolymer, surpassing those of traditional epoxy resins. This enhancement in thermal performance amplifies with an increase in the content of the APNH monomer. The research indicates that the EPNH copolymer exhibits superior thermal stability and elevated glass transition temperatures, facilitating the application of epoxy resin in specialized areas.

Improvement of Perovskite Solar Cells Efficiency by Management of the Electron Withdrawing Groups in Hole Transport Materials: Theoretical Calculation and Experimental Verification.

Management of functional groups in hole transporting materials (HTMs) is a feasible strategy to improve perovskite solar cells (PSCs) efficiency. Therefore, starting from the carbazole-diphenylamine-based JY7 molecule, JY8 and JY9 molecules are incorporated into the different electron-withdrawing groups of fluorine and cyano groups on the side chains. The theoretical results reveal that the introduction of electron-withdrawing groups of JY8 and JY9 can improve these highest occupied molecular orbital(HOMO)energy levels, intermolecular stacking arrangements, and stronger interface adsorption on the perovskite. Especially, the results of molecular dynamics (MD) indicate that the fluorinated JY8 molecule can yield a preferred surface orientation, which exhibits stronger interface adsorption on the perovskite. To validate the computational model, the JY7-JY9 are synthesized and assembled into PSC devices. Experimental results confirm that the HTMs of JY8 exhibit outstanding performance, such as high hole mobility, low defect density, and efficient hole extraction. Consequently, the PSC devices based on JY8 achieve a higher PCE than those of JY7 and JY9. This work highlights the management of the electron-withdrawing groups in HTMs to realize the goal of designing HTMs for the improvement of PSC efficiency.

Selective cyanide ion detection using hydrazine carbothioamide probe: A fluorescence turn-on approach

This study reports the synthesis of various hydrazine carbothioamide derivatives through a Schiff base reaction, confirmed by FT-IR, NMR (1H and 13C), and HRMS spectroscopic methods. Among the synthesized derivatives, probe L ((4-fluorobenzylidene)-2-(1-phenylethylidene)hydrazine-1-carbothioamide) was identified as a highly selective fluorometric chemosensor based on its absorbance and emission spectra. Probe L showed a CN− ion-specific turn-on fluorescence response, with very little interference from other anions. Job's method established a 1:1 binding stoichiometry among probe L and the cyanide ion. The detection limits (LOD) and quantification (LOQ) were observed to be 0.639 µM and 2.116 µM, respectively. With the use of FT-IR spectroscopy, 1H NMR titration, 13C NMR and HRMS, the binding mechanism was clarified. Moreover, probe L was employed effectively for detecting CN− ions in water and food samples, highlighting its potential as a practical sensor for cyanide detection.

Fexinidazole optimization: enhancing anti-leishmanial profile, metabolic stability and hERG safety.

The lack of adequate anti-leishmanial therapies has led to the continued suffering of millions of people from developing nations. Moreover, optimism for a therapeutic intervention by fexinidazole was dashed due to the inability to maintain cures and control unwanted side effects. To solve these shortcomings, the structural elements of fexinidazole responsible for anti-leishmanial activity and toxicities were explored. Accordingly, a systematic analog design approach was taken for the synthesis of 24 novel analogs. We established the structural features important for activity and identified modifications that improved the hERG receptor safety and liver microsomal metabolic stability. Compared to fexinidazole, the S-configured imidazolooxazole analog 51 exhibited 25-fold greater potency against miltefosine resistant L. donovani amastigotes, greater metabolic stability and little hERG receptor inhibition. Replacement of the toxicophore nitro group for a cyano group resulted in a complete loss of anti-leishmanial activity. The SAR findings should be useful in the further development of this important class of anti-leishmanial agents.

Synthesis of Carbon Nitride Polymorphs by Sacrificial Template Method: Correlation between Physicochemical Properties and Photocatalytic Performance.

Carbon nitride compounds (CNCs) in the form of graphitic carbon nitride (g-C3N4) and poly(heptazine imide) were synthesized using different metal chloride salts (MClx), i.e., NaCl, KCl and CaCl2, as sacrificial templates and by varying the MClx to melamine molar ratios. A systematic study of their photocatalytic activity for H2 production in relation to the physicochemical, morphological, and optical properties was carried out. Each sample was tested achieving the highest hydrogen evolution rates of about 7660 µmol g-1 h-1, 5380 µmol g-1 h-1 and 3140 µmol g-1 h-1 using CaCl2, KCl, and NaCl, respectively. This work demonstrates how the synthesis of CNCs with different MClx leads to the production of high-performance photocatalysts due to a combination of factors as the formation of vacancies or cyano groups, a shift in the optical threshold and tuning of micro(nano)structure. The results demonstrate that, when CaCl2 is used as a sacrificial template, porous and exfoliated g-C3N4 nanosheets are formed leading to hydrogen productions which outperform most of the previously reported g-C3N4 prepared using a single synthetic step.

Dipole Orientation Engineering in Crosslinking Polymer Blends for High-Temperature Energy Storage Applications.

Polymer dielectrics that perform efficiently under harsh electrification conditions are critical elements of advanced electronic and power systems. However, developing polymer dielectrics capable of reliably withstanding harsh temperatures and electric fields remains a fundamental challenge, requiring a delicate balance in dielectric constant (K), breakdown strength (Eb), and thermal parameters. Here, amide crosslinking networks into cyano polymers is introduced, forming asymmetric dipole pairs with differing dipole moments. This strategy weakens the original electrostatic interactions between dipoles, thereby reducing the dipole orientation barriers of cyano groups, achieving dipole activation while suppressing polarization losses. The resulting styrene-acrylonitrile/crosslinking styrene-maleic anhydride (SAN/CSMA) blends exhibit a K of 4.35 and an Eb of 670 MV m-1 simultaneously at 120°C, and ultrahigh discharged energy densities (Ue) with 90% efficiency of 8.6 and 7.4 J cm-3 at 120 and 150°C are achieved, respectively, more than ten times that of the original dielectric at the same conditions. The SAN/CSMA blends show excellent cyclic stability in harsh conditions. Combining the results with SAN/CSMA and ABS (acrylonitrile-butadiene-styrene copolymer)/CSMA blends, it is demonstrated that this novel strategy can meet the demands of high-performing dielectric polymers at elevated temperatures.

Electro-inductive Effects and Molecular Polarizability for Vibrational Probes on Electrode Surfaces.

A microscopic understanding of electric fields and molecular polarization at interfaces will aid in the design of electrocatalytic systems. Herein, variants of 4-mercaptobenzonitrile are designed to test different schemes for breaking the continuous conjugation between a gold electrode surface and a nitrile group. Periodic density functional theory calculations predict applied potential dependencies of the CN vibrational frequencies similar to those observed experimentally. The CN frequency response decreased more when the conjugation was broken between the benzene ring and the nitrile group than between the electrode and the benzene ring, highlighting molecular polarizability effects. The systems with continuous or broken conjugation are dominated by electro-inductive effects or through-space electrostatic effects, respectively. Analysis of the fractional charge transfer between the electrode and the molecule as well as the occupancy of the CN antibonding orbital provides further insights. Balancing the effects of molecular polarizability, electro-induction, and through-space electrostatics has broad implications for electrocatalyst design.

Polymer Composite Electrolytes Membrane Consisted of Polyacrylonitrile Nanofibers Containing Lithium Salts: Improved Ion Conductive Characteristics and All‐Solid‐State Battery Performance

AbstractPolymer electrolyte membranes with superior lithium‐ion (Li+) conductivity and sufficient electrochemical stability are desired for all‐solid‐state lithium‐ion batteries (ASS‐LIBs). This paper reports novel polymer composite membranes consisting of polyacrylonitrile (PAN) nanofibers (Nfs) containing lithium salts. It is first revealed that the lithium salt addition increases polar surface groups on the PAN nanofibers. Subsequently, the lithium salts‐containing PAN nanofiber (PAN/Li Nf) composite membrane affects the matrix poly(ethylene oxide) (PEO)/lithium bis(trifluoromethyl sulfonylimide) (LiTFSI) electrolyte to increase the numbers of Li+ with high mobility. Consequently, the PAN/Li Nf composite membrane shows relatively good ion conductivity (σ = 9.0 × 10−5 S cm−1) and a considerably large Li+ transference number (tLi+ = 0.41) at 60 °C, compared to the PEO/LiTFSI membrane without nanofibers. The 6Li solid‐state NMR study supports that the PAN/Li Nf bearing abundant polar nitrile groups at their surface enhances Li+ diffusion in the PEO‐based electrolyte membranes. The galvanostatic constant current cycling tests reveal that the PAN/Li Nf composite membrane possesses good electrochemical and mechanical stabilities. The ASS‐LIB consisting of the PAN/Li Nf composite membrane shows significantly improved charge and discharge cycling performances, promising future all‐solid‐state batteries.