NaSCN Research Articles

Ternary Liquid-Liquid Equilibria in a Few Nonaqueous Two-Phase Systems

AbstractThe composition of coexisting phases for liquid-liquid and solid-liquid-liquid equilibria were measured at 298.2 and 313.2 K and under atmospheric pressure for the following systems: {sodium bromide + formamide + ethyl acetate}, {sodium thiocyanate + ethanol + (R)-limonene}, and {sodium thiocyanate + methanol + dibutyl ether}. These concentrations were determined mainly by chromatography and, for the first system, with the help of argentometric titration. The standard uncertainties in mole fractions varied between 0.001 and 0.008. The tie-line data were reproduced by the NRTL model with medium accuracy. Several empirical equations were used and tested to correlate binodal curves. The rational form of the equation, based on the liquid–liquid–solid tie-line, turned out to be the most adequate.

Novel Ratiometric Surface-Enhanced Raman Scattering (SERS) Biosensor for Ultrasensitive Quantitative Monitoring of Human Carboxylesterase-1 in Hepatocellular Carcinoma Cells Using Ag-Au Nanoflowers as SERS Substrate.

In this study, we developed ratiometric surface-enhanced Raman scattering (SERS) biosensors using Ag-Au alloy nanoflowers as SERS substrates, molecules having amide bonds and alkyne groups (Tag A) as Raman reporters, and sodium thiocyanate as an internal standard molecule (Tag B) for the sensitive detection of human carboxylesterase-1 (hCE1) in HepG-2 cells. The correlation between HepG-2 cell damage and hCE1 activity levels was investigated. Both Tag A's alkyne group and Tag B's cyanide group produced characteristic SERS signals in the Raman-silent region (I2000cm-1 and I2115cm-1, respectively). The hydrolysis of the amide bond in Tag A via hCE1 and the shedding of the alkyne group led to a reduction in the SERS signal intensity observed at I2000cm-1. Conversely, the SERS signal intensity of Tag B at I2115cm-1 exhibited a consistent pattern. As the activity level of hCE1 and the ratiometric peak intensity (I2000cm-1/I2115cm-1) correlated negatively, hCE1 could be quantitatively detected within the range of 10-2 to 2 × 102 ng·mL-1, with a detection limit of 7.3 pg·mL-1. The ratiometric SERS probe strategy, in which a ratio response is employed, permits sensitive and reproducible SERS detection by facilitating intrinsic calibration to rectify signal fluctuations resulting from temporal and spatial variations in the detection conditions. Concurrently, the implementation of Raman-silent region reporter molecules mitigates the interference from endogenous biomolecules in SERS measurements and offers a novel approach for achieving highly sensitive and interference-free detection of intracellular hCE1.

Study of the use of sodium thiocyanate as an indicator for three-dimensional dosimetry

Three-dimensional dosimetry allows the determination of dosimetric quantities with a volumetric gradient. With Fricke Gel it is possible to make measurements of this nature due to the restriction of ions in this dosimeter caused by the presence of a gelatinous matrix. When ion indicators are added to Fricke Gel, the diffusion of the ions is further hampered and, in addition, the use of optical measurement techniques for the determination of the absorbed dose becomes possible. In this study, a new ferric ion indicator possibility for Fricke Gel is evaluated. Sodium thiocyanate was added to the Fricke Gel matrix and the effect of this addition was analyzed in a gamma radiation field and in a high-energy electron beam. The obtained results demonstrated the possibility of using this indicator as a binding agent in the Fricke Gel dosimeter. In the gamma irradiation field, the dosimeter showed a linear response with the absorbed dose between 5 Gy and 150 Gy, in addition to presenting visual evidence of the spatial distribution of the radiation field to which it is subjected.

Synthesis of N-Aryl-4-trifluoromethylthiazol-2-amines via Insertion/Annulation of Trifluoromethylimidoyl Sulfoxonium Ylides with Sodium Thiocyanate.

An efficient p-TsOH-mediated insertion of sodium thiocyanate into trifluoromethylimidoyl sulfoxonium ylides has been reported, affording annulated N-aryl-4-trifluoromethylthiazol-2-amines in 42-84% yields in a one-pot manner. This protocol encompasses a variety of trifluoromethylimidoyl sulfoxonium ylides with thiocyanate serving as the source of the "S-C═N" moiety of the thiazole ring. The versatile transformations of the resulting pharmacologically important N-aryl-4-trifluoromethylthiazol-2-amines were also demonstrated.

Design, structure and antivirus molecular docking of chloridobis(1,10-phenanthroline)-(thiocyanato)-copper(II)

The reaction of sodium thiocyanate with CuCl2·2H2O salt using 1,10-phenanthtroline as a co-ligand led to chloridobis(1,10-phenanthroline)-(thiocyanato) copper(II), [Cu(Phen)2(Cl)(NCS)] (1). The structure of 1 was characterized by single crystal X-ray crystallography, UV-Visible and fluorescence spectroscopy. 1 crystallized in the monoclinic crystal system with space group P21/n and revealed a distorted octahedral coordination geometry. Electronic properties such as HOMO and LUMO energies were derived through DFT calculations. Hirshfeld surface analysis and 2D fingerprint plot was used to analyze the intermolecular interactions within the crystal structure. To develop anti-SARS-CoV-2 and anti-HIV drugs, we performed molecular docking studies for antiviral activity against the main protease (Mpro) of the SARS-CoV-2 (PDB ID: 6LU7 and 7LKD) and HIV-1 protease (PDB ID: 8FUI) viruses. The molecular docking calculations reveal that 1 with the Mpro of SARS-CoV-2 virus and HIV-1 protease virus resulted in calculated binding energies (ΔG) of −7.6, −7.5 and −7.2 kcal/mol with inhibition constant/dissociation constant (Ki/Kd ) values of 4.567, 4.432 and 4.632 µM, respectively. The in-vitro antibacterial study was conducted to check the efficacy of 1 against some selected bacteria. Further, the in-silico antiviral efficacy analysis shows the potential of this complex as an antiviral drug. 1 may be used as anti-SARS-CoV-2 and anti-HIV-1 agents.

NaSCN‐Induced Cyano‐Rich Porous Graphitic Carbon Nitride with Sodium Dopant and Nitrogen Vacancies for Enhanced Photosynthesis of Hydrogen Peroxide

AbstractDefect engineering has been considered as an efficient and facile tactics to optimize the bandgap structure and improve the oxygen adsorption ability of graphitic carbon nitride (g‐C3N4). Herein porous g‐C3N4 with nitrogen vacancies and sodium dopant as well as cyano (─C≡N) groups has been successfully constructed by direct pyrolysis of melamine in the presence of cyano‐rich sodium thiocyanate (NaSCN). Moreover, the incorporation of NaSCN is interestingly found to induce the relative high content of ─C≡N groups compared to other inorganic sodium compounds (NaCl, NaOH, and Na2SO4), which has been experimentally demonstrated to be beneficial for extending the light absorption range and promoting the efficient separation of photo‐generated electron–hole pairs as well as improving the oxygen adsorption ability. Benefiting from the above features, the optimal photocatalyst exhibits high H2O2 yield of 438.2 µm within 4 h and excellent cyclic stability.

Development of Cyanopyridazine Derivatives as Photoredox Catalysts and Evaluation of their Catalytic Performance

AbstractAn array of cyanopyridazine derivatives have been developed through a sequence of (3+3) cycloaddition/oxidative aromatization/derivatization steps. Investigation of the physicochemical properties of these compounds shows that four have interesting fluorescence properties and have the potential to be developed into bimodal photoredox catalysts. One has been confirmed to be an photoredox catalyst in the reactions of N‐aryl‐ tetrahydroisoquinolines with phosphite, nitromethane, malonitrile and sodium thiocyanate, led to 22%–95% yields. The catalyst capabilities remain with recyclable using under the reaction conditions.

Poly(Vinylidene Fluoride‐CO‐Hexafluoropropylene) (PVDF‐HFP) Incorporated Acetylene Black: Electrical, Optical, and Structural Studies

AbstractThe primary goal of this study is to synthesize a high‐conducting polymer electrolyte film. The PVDF‐HFP and NaSCN film are prepared which showed the highest conductivity at 30 wt% dopant of NaSCN in the Polymer PVDF‐HFP which is 1.24× 10−4 S cm−1. Therefore, here the base polymer is taken as PVDF‐HFP and NaSCN (30 wt%) and further Acetylene Black is added to check the variation in the conductivity of the polymer film. Solution casting technique is used to create solid polymer electrolyte films using poly(vinylidene fluoride‐co‐hexafluoropropylene) (PVDF‐HFP) with salt sodium thiocyanate and Acetylene Black. Polarized optical microscopy (POM) is used to evaluate the morphology of the polymer film surface. Fourier transform infrared spectroscopy (FTIR) to check the presence of functional group is used, impedance spectroscopy is used for the measurement of the conductivity of the sample, linear sweep voltammetry for finding electrical stability window, and transference number measurements for concentration of charge carriers are done for the electrical studies of polymeric films. The 1 wt% Acetylene Black doped polymer electrolyte film is found to have the maximum ionic conductivity, which is 1.95 × 10−3 S cm−1. The solid polymer electrolyte film has an electrochemical stability window (ESW) of 4.8 V and tion value of 0.83.

Multi-Species Surface Reconstruction for High-Efficiency Perovskite Nanocrystal Light-Emitting Diodes.

Although colloidal perovskite nanocrystal (PNC) solution has exhibited near-unity photoluminescence quantum yield (PLQY), the luminance would be severely quenched when the PNC solution is assembled into thin films due to the agglomeration and fusion of NCs caused by the exfoliation of surface ligands and non-radiative Förster resonance energy transfer (FRET) from small to large particle sizes, which seriously affected the performances of light-emitting diodes (LEDs). Here, we used Guanidine thiocyanate (GASCN) and Sodium thiocyanate (NaSCN) to achieve effective CsPbI3 PNC surface reconstruction. Due to the strong coordination ability of these small molecules with the anions and cations on the surface of the PNCs, they can provide strong surface protection against PNC fusion during centrifugal purification process and repair the surface defects of PNCs, so that the original uniform size distribution of PNCs can be maintained and FRET between close-packed PNC films is effectively suppressed, which allows the emission characteristics of the films to be preserved. As a result, highly oriented, smooth and nearly defect-free high-quality PNC thin films are obtained, with PLQY as high as 95.1 %, far exceeding that of the original film, and corresponding LEDs exhibit a maximum external quantum efficiency of 24.5 %.

Multi‐Species Surface Reconstruction for High‐Efficiency Perovskite Nanocrystal Light‐Emitting Diodes

AbstractAlthough colloidal perovskite nanocrystal (PNC) solution has exhibited near‐unity photoluminescence quantum yield (PLQY), the luminance would be severely quenched when the PNC solution is assembled into thin films due to the agglomeration and fusion of NCs caused by the exfoliation of surface ligands and non‐radiative Förster resonance energy transfer (FRET) from small to large particle sizes, which seriously affected the performances of light‐emitting diodes (LEDs). Here, we used Guanidine thiocyanate (GASCN) and Sodium thiocyanate (NaSCN) to achieve effective CsPbI3 PNC surface reconstruction. Due to the strong coordination ability of these small molecules with the anions and cations on the surface of the PNCs, they can provide strong surface protection against PNC fusion during centrifugal purification process and repair the surface defects of PNCs, so that the original uniform size distribution of PNCs can be maintained and FRET between close‐packed PNC films is effectively suppressed, which allows the emission characteristics of the films to be preserved. As a result, highly oriented, smooth and nearly defect‐free high‐quality PNC thin films are obtained, with PLQY as high as 95.1 %, far exceeding that of the original film, and corresponding LEDs exhibit a maximum external quantum efficiency of 24.5 %.

Early strength enhancement of high-volume fly ash mortar using accelerating admixtures

High-volume fly ash mortar is considered a "green" material, a sustainable development solution for the construction industry, in which the fly ash replacement Portland cement content is over 50%. However, this material has the major disadvantage of slow strength development, especially at an early age, which limits its applicability. To overcome the above disadvantage, the individual or combined addition of lime Ca(OH)2, silica fume, and/or accelerating admixtures including sodium thiocyanate (NaSCN), diethanolamine (DEA), and glycerol (Gly), etc. have been interested recently. In this study, to enhance the early strength of mortars with fly ash content to replace 60÷80% of Portland cement, a three-component accelerating admixture of NaSCN, DEA, and Gly (2:1:0.5 by the mass) was used with different ratios of 0.21÷0.49 % by the total powder mass, combined with a reasonable amount of lime, silica fume supplement as presented in previous research. Experimental results showed that the optimal accelerating admixture content is 0.35% by weight of powder, combined with 6% silica fume and the additional amount of lime is 5%; 10%; and 15% corresponding to mortars using fly ash of 60%; 70% and 80%, respectively to improve early strength of mortars that are suitable for structural use (R3 ≥ 13MPa, 3 days old). In addition, the influence of the additives used on the initial setting time of high-volume fly ash mortars was also discussed.

Sulfur functionalized biocarbon sorbents for low-concentration mercury isolation.

Sulfur functionalized biocarbons were prepared from naturally abundant lignin alkali with sodium thiocyanate as an activation agent and a sulfur source. The resultant biocarbon sorbents showed a high mercury isolation ability from aqueous solutions, where high surface area and doping of sulfur significantly aid the uptake of mercury, i.e., 0.05 g of biocarbon sorbent removed 99% of mercury from 250 mL of simulated wastewater with an initial concentration of mercury of 10 mg L-1.

Investigation of supramolecular structures in various aqueous solutions of an amyloid forming peptide using small-angle X-ray scattering.

Aggregation of peptide molecules into amyloid fibrils is a characteristic feature of several degenerative diseases. However, the details behind amyloid-formation, and other self-assembled peptide aggregates, remain poorly understood. In this study, we have used small-angle X-ray scattering (SAXS), static and dynamic light scattering (SLS and DLS) as well as cryogenic transmission electron microscopy (cryo-TEM) to determine the structural geometry of self-assembled peptide aggregates in various dilute aqueous solutions. Pramlintide was used as a model peptide to assess the aggregation behaviour of an amyloid-forming peptide. The effects of adding sodium chloride (NaCl), sodium thiocyanate (NaSCN), and sodium fluoride (NaF) and the co-solvent dimethyl sulfoxide (DMSO) on the aggregation behaviour were studied. Our scattering data analysis demonstrates that small oligomeric fibrils aggregate to form networks of supramolecular assemblies with fractal dimensions. The choice of anion in small amounts of added salt has a significant impact on the size of the fibrils as well as on the fractal dimensions of supramolecular clusters. In DMSO the fractal dimension decreased with increasing DMSO concentration, indicating the formation of a less compact structure of the supramolecular assemblies.

Copper-mediated [3 + 2] oxidative cyclization of oxime acetate and its utility in the formal synthesis of fentiazac.

A new protocol for the direct synthesis of 2-aminothiazole has been developed from oxime acetate and readily available sodium thiocyanate using a copper catalyst. The present transformation has good functional group tolerance. Various thiazoles were smoothly synthesized in good to excellent yields. The applicability of the present method has been extended to the formal synthesis of the non-steroidal and anti-inflammatory drug, fentiazac via the Sandmeyer reaction and Suzuki coupling.

Flotation behavior and mechanism of smithsonite under the system of bidentate ligand sulfide sodium thiocyanate

The sulfuration pretreatment is essential in enhancing the floatability of zinc oxide ore during the flotation process. The conventional vulcanizing agent employed in the sulfuration process, however, has proven to be ineffective and environmentally unfriendly. The dosage of this agent must be strictly regulated to ensure optimal flotation efficiency of zinc oxide ore, as excessive or insufficient amounts can have a negative impact. To address these issues, a more efficient and environmentally friendly vulcanization agent called sodium thiocyanate (NaSCN) has been introduced to enhance the sulfuration flotation of smithsonite. It also demonstrated the effective sulfidation of smithsonite by sodium thiocyanate, which also exhibits superior vulcanization effects compared to sodium sulfide. By applying NaSCN at a concentration of 6 × 10-4 mol/L, the recovery rate of zinc ore can achieve 88.75 %. Moreover, the vulcanization conditions utilizing sodium thiocyanate offer greater ease of management. The vulcanization mechanism of smithsonite was investigated through FTIR, Zeta potential, and XPS analysis. The findings indicate that the dentate ligand SCN– derived from sodium thiocyanate can undergo chemical adsorption onto the surface of smithsonite through either sulfur (S) or nitrogen (N) elements. The interaction leads to the formation of zinc-thiocyanate anions, which enhance the surface hydrophobicity and expand the mineral collection sites. The overall findings suggest that sodium thiocyanate exhibits promising potential as a highly efficient vulcanization agent for smithsonite, providing valuable insights for the flotation of this mineral.

Steps towards the ideal CV and GCD results with biodegradable polymer electrolytes: Plasticized MC based green electrolyte for EDLC application

Advanced materials are a primary focus of many research groups for applications in energy storage devices. Natural polymers, as a branch of advanced materials, are currently a hot topic to produce clean energy and reduce microplastics problems in the ocean and their potential harm to human health through ingestion. A novel biodegradable green polymer electrolyte was selected for energy storage in the current investigation. The MC polymer was impregnated with a fixed weight percent (40 %) of sodium thiocyanate (NaSCN) and different amount of glycerol to produce flexible films of solid polymer electrolytes (SPEs) using solution casting method. The XRD test reveals that the lowest degree of crystallinity is present in the most conductive electrolyte with increasing plasticizer. According to the electrochemical impedance spectroscopy (EIS) results, the sample that was incorporated with 50 % glycerol displayed the highest conductivity. FTIR was employed to observe the interaction of electrolyte components. Ions were found to be the primary species contributing to conduction, with transference numbers of 0.958 and 0.042 for ions (tion) and electrons (te), respectively. The results obtained from the linear sweep voltammetry (LSV) data confirm that the sample can withstand a voltage of approximately 2.54 V. This voltage level is suitable for extensive practical applications. The shape of the CV pattern was almost comparable to an ideal rectangular shape at low scan rates. A slight increase in the internal resistance (ESR) of the EDLC cell was observed, which increased from 59 to 68 Ω. The battery cycler was used to charge and discharge the designed EDLC device and some key parameters, including capacitance (110 F.g−1), energy density (15 Wh.Kg−1), and power density (1300 W.Kg−1) were determined from the discharge curve. Ultimately, based on the study of the assembled cell, it has been suggested that supercapacitors have emerged as potential alternative to replace environmentally harmful Li-ion batteries in advancing green energy.

Clean energy storage device derived from biopolymers with moderate charge-discharge cycles: Structural and electrochemical properties

This work explores a green biopolymer (GBP) energy storage system to address the growing problem of microplastics that can harm our health. A GBP was made using solution casting with chitosan (CHN) and starch from potato (SPC) as the polymer hosts. Sodium thiocyanate (NaSCN) as Na+ cation provider and glycerol as an environmentally friendly plasticizer were mixed with CHN:SPC host polymers to prepare GBP electrolytes. The electrochemical impedance spectroscopy (EIS) results confirm the boost in DC conductivity. From the AC conductivity spectra, regions ascribing to EP and DC contributions are demonstrated. X-ray diffraction (XRD) and FTIR characterization provide evidence of salt dissociation and amorphous phase improvement. The determination of the ion fraction was achieved by means of TNM. The electrochemical stability of the conducting film was observed to be maintained up to 2.75 V. Cyclic voltammetry (CV), revealing no sign of charge transfer occurring through Faradaic processes at the interface between the electrode and electrolyte. The galvanostatic charge–discharge (GCD) plot displayed a triangular pattern, indicating a low voltage drop and a notable specific capacitance of 70 F/g. Moreover, the EDLC (electrical double-layer capacitor) exhibited an average power density of 1120 W/kg and an energy density of 9.11 Wh/kg.

Hydrogen-Deuterium Exchange Dynamics of NISTmAb Measured by Small Angle Neutron Scattering.

Understanding protein dynamics and conformational stability holds great significance in biopharmaceutical research. Hydrogen-deuterium exchange (HDX) is a quantitative methodology used to examine these fundamental properties of proteins. HDX involves measuring the exchange of solvent-accessible hydrogens with deuterium, which yields valuable insights into conformational fluctuations and conformational stability. While mass spectrometry is commonly used to measure HDX on the peptide level, we explore a different approach using small-angle neutron scattering (SANS). In this work, SANS is demonstrated as a complementary and noninvasive HDX method (HDX-SANS). By assessing subtle changes in the tertiary and quaternary structure during the exchange process in deuterated buffer, along with the influence of added electrolytes on protein stability, SANS is validated as a complementary HDX technique. The HDX of a model therapeutic antibody, NISTmAb, an IgG1κ, is monitored by HDX-SANS over many hours using several different formulations, including salts from the Hofmeister series of anions, such as sodium perchlorate, sodium thiocyanate, and sodium sulfate. The impact of these formulation conditions on the thermal stability of NISTmAb is probed by differential scanning calorimetry. The more destabilizing salts led to heightened conformational dynamics in mAb solutions even at temperatures significantly below the denaturation point. HDX-SANS is demonstrated as a sensitive and noninvasive technique for quantifying HDX kinetics directly in mAb solution, providing novel information about mAb conformational fluctuations. Therefore, HDX-SANS holds promise as a potential tool for assessing protein stability in formulation.

Crystallographic, antibacterial, and in silico studies of Ni(II) and Cu(II) Schiff base complexes derived from 2-acetylpyridine

Two Schiff base complexes, namely Ni(L1)(NCS)2 (2) and Cu(L1)(NCS).SCN (3) (where L1 = [N,N′-bis(1-(pyridin-2-yl)ethylidene)propane-1,3-diamine]) have been synthesized through condensation of L1 with metal acetates using a 2:1 ratio, in the presence of sodium thiocyanate, NaSCN. The complexes were characterized by elemental analysis, IR, UV–Vis, magnetic moment, as well as molar conductivity. The crystal structures of complexes 2 and 3 were successfully characterized by single crystal X-ray crystallography. The Ni atom in 2 is in a distorted octahedral environment while the Cu atom in 3 is in an environment lying between square pyramidal and trigonal bipyramidal; in both complexes the NCS− is acting as terminal ligand. Both complexes were paramagnetic. Density functional theory (DFT) calculations were performed at the B3LYP/LanL2DZ level of theory to explore the quantum chemical properties of the ligand and its metal complexes. The calculations proceed with the 3D crystal structure characterization of the complexes, and the correlation between theoretical and experimental results were discussed. NBO analysis was used to determine the strength of donor–acceptor interactions in metal complexes. The antibacterial activity of the synthesized compounds was screened in vitro against two strains of Gram-positive (Staphylococcus (S.) aureus, Staphylococcus (S.) haemolyticus) and three strains of Gram-negative (Shigella (S.) sonnei, Salmonella (S.) typhimurium, Enterobacter (E.) aerogenes) bacteria, and showed no activity. The binding affinity of the synthesized complexes in the binding site of S. aureus tyrosyl-tRNA was investigated using molecular docking, and the outcomes showed a good agreement with experimental results.

Quality attributes of set yogurt made from lactoperoxidase system activated cow’s milk

The study aimed to assess the quality attributes of set yoghurt made from cow's milk preserved by lactoperoxidase system (LPs). Fresh cow's milk was collected from Datto milk collection center and samples were grouped to control and LPs activated. Set yoghurt was prepared immediately for the controlled samples, but in LPs activated milk, sample was kept for 9 h at 25 °C ± 2 before yoghurt was made. LP enzyme was activated within 2 h after milking by adding 1 mg/ml of sodium thiocyanate (SCN_) and hydrogen peroxide (H2O2). Totally, 36 L of cow's milk was used and the experiment was done in triplicates. Titratable acidity (TA) and pH were assessed every 30 min until coagulation formed. Yoghurt samples were stored for 21 days and different parameters were assessed including incubation duration, pH, TA, microbiological quality and sensory attributes. The results revealed that LPs partially suppressed the rate of acid production during incubation of cultured milk. Yoghurt made from LPs treated milk had significantly (P < 0.05) higher pH and lower TA values. Similarly, yoghurt made from LPs treated milk had lower total bacterial counts at 24-h, 72-h and 7-days of storages. Additionally, yoghurt from LPs activated milk had lower yeast and mold counts at 24-h and 7-days. Yoghurt made from LPs activated milk received better scores for the sensory attributes. In general, LPs activated milk can be used for making set yoghurt without a negative effect. Further studies are needed to illustrate the LPs activated milk fitness in making other cultured milk products.