A novel bidentate Schiff base (L) is here proposed for the detection of Zn ions in water. The structure of the synthesized Schiff base L was characterized by FT-IR,
H NMR and
C NMR. Optical ...characteristics were addressed by UV-Visible spectroscopy and Photoluminescence (PL) measurements. PL demonstrated that L displays a "turn-off" type fluorescence quenching in the presence of Zn
ion in aqueous solution, indicating its ability to preferentially coordinate this ion. Based on these findings, an L-M (where M is a suitable membrane) modified screen-printed carbon electrode (SPCE) was developed to evaluate the electrochemical behavior of the Schiff base (L) with the final objective of undertaking the electroanalytical determination of Zn ions in water. Using various electrochemical techniques, the modified L-M/SPCE sensor demonstrates high sensitivity and selectivity to Zn ions over some common interferents ions, such as Ca
, Mg
, K
, Ni
and Cd
. The potentiometric response of the L-M/SPCE sensor to Zn ions was found to be linear over a relatively wide concentration range from 1 μM to 100 mM.
•A new nano-structure cobalt Schiff base complex was sonochemically prepared.•Crystal structure of the complex was described.•Hirshfeld surface analysis and 2D Fingerprint plots were used for ...investigation of Intermolecular interactions.•Thermal behavior of the complex was studied.•The nanostructure cobalt bromide complex was used for preparation of CoO/Co3O4 nanoparticles.
A bidentate Schiff base ligand and its nano-structured cobalt(II) complex were synthesized under ultrasound irradiation and then their structures were identified by physical and spectral techniques SEM and XRD techniques were used to confirm the nanostructure character of the complex. Single crystal X-ray diffraction analysis showed that the complex crystallizes in the triclinic system with space group of P1¯ and two crystallographically independent molecules participate in its asymmetric unit. In the structure of complex, cobalt center is four-coordinated by two iminic nitrogens of bidentate Schiff base ligand and two bromide anions in a distorted tetrahedral geometry. Crystal packing analysis well indicates that C–H⋯Br, C–H⋯π and π⋯π are the most intermolecular interactions. Moreover Hirshfeld surface analysis and 2D Fingerprint plots were applied for more investigation of intermolecular interactions. In addition, sonochemically prepared cobalt(II) bromide complex was subjected to calcination process under air atmosphere for preparation of cobalt oxide nanoparticles. The XRD pattern confirmed the simultaneous formation of CoO and Co3O4 nanoparticles.
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•Two cost effective adsorbent was proposed for dyes adsorption from water.•Five variables of initial dyes concentration, adsorbent dosage, pH and sonication time were ...involved.•Significant variables were investigated using the response surface methodology.•Natural pH and low sonication time values are favorable for the removal of hazardous dyes.•Two models, RSM and ANN have been developed for prediction of dyes adsorption.•The dyes adsorption data were best followed by Langmuir and pseudo-second order models.
Multiwalled carbon nanotubes (MWCNTs) functionalized with (N-3-phenylallaylidene)-N′-trimethoxysilylpropyl-ethane-1,2-diamine (PATMSPEDA) were prepared and subsequently the MWCNTs-PATMSPEDA-Pd-NPs nanohybrids with high shape selectivity and high specific surface area have been prepared by single step synthesis of Pd nanoparticles (Pd-NPs) loaded on MWCNTs-PATMSPEDA. These materials were characterized by different techniques such as XRD, SEM, FT-IR and TGA-DTA and subsequently were used for the simultaneous ultrasound-assisted removal of erythrosine (ER) and sunset yellow (SY) dyes from aqueous solution. The influences of important variables such as initial dyes concentration, adsorbent dosage, pH and sonication time on the efficiency of ultrasound-assisted removal process were investigated by central composite design (CCD) and the optimization conditions were obtained 4.39 and 4.33mgL−1 of ER concentration, 11.76 and 11.90mgL−1 of SY concentration, 0.02 and 0.019g adsorbent mass, 7.0 and 7.0 for pH value and 3.88 and 3.75min sonication time for MWCNTs-PATMSPEDA and MWCNTs-PATMSPEDA-Pd-NPs, respectively. The artificial neural network (ANN) model was used for constructing an empirical model to predict the understudy dyes removal behavior onto these adsorbents and the obtained results have good agreement with experimental data. The absolute average deviations (AADs) of ER and SY dyes adsorption by MWCNTs-PATMSPEDA are 0.62% and 0.58%, and the determination coefficient (R2) values are 0.971 and 0.978, respectively. Also, the AADs of ER and SY dyes adsorption by MWCNTs-PATMSPEDA-Pd-NPs are 0.48% and 0.34%, and the R2 values are 0.971 and 0.972, respectively. Finally, it was found that the equilibrium isotherm of adsorption process follows the Langmuir isotherm. From the Langmuir isotherm, maximum monolayer capacity (qmax) were obtained to 30.58 and 38.76mgg−1 and 55.25 and 59.17mgg−1 at optimum conditions for ER and SY removal onto MWCNTs-PATMSPEDA and MWCNTs-PATMSPEDA-Pd-NPs, respectively.
Multi-walled carbon nanotubes (MWCNT) was oxidized and chemically functionalized by 3-hydroxy-4-((3-silylpropylimino) methyl) phenol (HSPIMP) and characterized with FT-IR technique. This new sorbent ...was used for enrichment and preconcentration of Cu2+, Ni2+, Zn2+, Pb2+, Co2+, Fe3+ ions. Variables such as pH, amount of solid phase, eluting solution conditions (type, volume and concentrations) have significant effect on sorption and recoveries of analytes and the influence was optimized. At optimum value of conditions, the interference of other ions on understudy ions recoveries was investigated. The metal ions loaded on the solid phase via chelation with the new sorbent and subsequently efficiently eluted using 6mL of 4molL−1 HNO3 solution. At each run, metal ions content was determined by flame atomic absorption spectrometry (FAAS). Relative standard deviation (N=3) for determination of 0.2μgmL−1 of analytes was between 1.6 and 3.0%, while their detection limit was between 1.0 and 2.6ngmL−1 (3Sb, n=10). The sorption capacity of HSPIMP–MWCNT for understudy ions was above 30mgg−1. The proposed method successfully applied for the extraction and determination of the understudy metal ions in different samples.
•Some new four coordinated cadmium complexes were synthesized.•Cadmium complexes showed suitable antibacterial/antifungal activity against some bacterial and fungal strains.•The thermal behaviors of ...cadmium complexes were studied.•Some activation thermodynamic parameters were evaluated based on TG/DTG/DTA plots.
Four new cadmium(II) Schiff base complexes formulated as CdLX2 (X=Cl−, Br−, I−, SCN− and L=bis (3(4-dimethylaminophenyl)-allylidene)-1,2-diaminoethane) were synthesized. All novel compounds were identified by spectroscopic techniques including FT-IR, 1H and 13C NMR, UV–vis spectra and physico-chemical methods such as molar conductivity, elemental analysis and melting point. Based on the physical and spectral evidences, the pseudo-tetrahedral geometry was proposed for all complexes. The in vitro antibacterial/antifungal activity of each compound was screened against four bacterial strains such as Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa as well as two fungal pathogens such as Candida albicans and Aspergillus niger. The biological testing data showed that all compounds were antimicrobial active against both Gram-positive and Gram-negative bacteria and two fungal strains. The bactericidal/fungicidal properties of compounds showed that the cadmium complexes were more bioactive than the parent ligand. Furthermore, the thermal behavior of all compounds was studied. The ligand was completely destructed through three temperature stages. Among the cadmium complexes, the CdL(NCS)2was found as the most stable while the CdLCl2 showed the least thermal stability. Besides some activation thermodynamic parameters such as E*, ΔH*, ΔS*, ΔG* were calculated using thermo-grams data by Coats–Redfern equation.
A novel symmetrical Schiff base ligand was prepared by condensation reaction of 2,2-dimethyl-1.3-diaminopropane and (E)3-(2nitrophenyl)acrylaldehyde. The ligand and its Zn(II) coordination compounds ...were well characterized by the elemental analysis, FTIR, 1H, 13C NMR, UV–vis spectra and molar conductance. Thermal behaviors of all compounds were investigated from the room temperature to 600°C with a heating rate of 10°C/min. Furthermore some decomposition thermo-kinetic parameters were evaluated by Coats–Redfern equation at each decomposition step. Electrochemical properties of ligand and its complexes were studied by cyclic voltammetry technique. Also antibacterial/antifungal activities of the ligand and its complexes were tested against three Gram-negative bacteria Escherichia coli (ATCC 25922), Salmonella spp. and Pseudomonas aeruginosa (ATCC 9027) and two Gram-positive bacteria Staphylococcus aureus (ATCC 6538) and Corynebacterium renale and also three fungi (Aspergillus niger, Penicillium chrysogenum and Candida albicans). The results exhibited suitable antibacterial/antifungal properties for ligand and Zn(II) complexes. The study has shown that the complexation of ligand to zinc center lead to enhancement of antibacterial/antifungal activity.
In this work, synthesis of some nano-structure five coordinated cadmium complexes of a new tridentate Schiff base ligand (L) under ultrasonic conditions is presented. The ligand and its cadmium ...complexes were characterized by various analyses such as FT-IR, UV–visible, 1H and 13C NMR spectra, XRD, SEM and TEM. According to applied techniques, the general formula of CdLX2 (X=Cl−, Br−, I−, SCN− and N3−) was suggested for the complexes. SEM, TEM and XRD analyses indicated that all complexes have nano-structure size in the range of 20–60nm. In the next step, ligand and its cadmium complexes were subjected for in vitro antibacterial activities against two Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis) and two Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa). Moreover in vitro antifungal properties of the compounds against Candida albicans and Aspergillus niger were investigated. The results indicated that all compounds show acceptable antibacterial and antifungal activities. Furthermore, the interaction of these complexes with DNA indicated that both ligand and its complexes can destruct the DNA structure. In final, thermal behaviors of all compounds were studied by TG/DTG/DTA analysis data. The thermo-diagrams showed that the compounds are decomposed via 2–3 temperature stages. Some thermo-kinetic activation data including Arrhenius constant, ΔE*, ΔH*, ΔS* and ΔG* of each thermal decomposition step were estimated graphically by use of experimental TGA data based on the Coats–Redfern equation.
Novel Cu2+ ion selective electrode in carbon paste matrices based on incorporation of bis(2-hydroxynaphthaldehydene)-1,6-hexanediamine (BHNHDA) has been developed. The influence of variables ...including sodium tetraphenylborate (NaTPB), ionophore, and amount of multiwalled carbon nanotubes (MWCNT) and Nujol and effect of two new nanoparticles including gold nanoparticles loaded on activated carbon (Au-NP-AC) and zinc sulfide nanoparticles loaded on activated carbon (ZnS-NP-AC) on the electrodes response was studied and optimized. At optimum specified conditions, the proposed electrodes have appropriate advantages such as short response times and suitable reproducibility and applicability for a period of at least 1 month without any significant divergence in slope and response properties. The sensor based on impregnations of MWCNT, Au-NP-AC and ZnS-NP-AC have wide linear range of concentration (6×10−8–1.0×10−1molL−1) and detection limit of lower than 4×10−8molL−1 of Cu2+ ion. The electrodes based on incorporation of Au-NP-AC and ZnS-NP-AC have Nernstian response with slope of 29.34±1.41 and 29.78±1.23mVdecade−1 and response is independent of pH in the range of 2.0–5.0. Finally, these electrodes have been successfully applied for the determination of Cu2+ ions content in various real samples. Due to their acceptable selectivity coefficient, they are usable for accurate and successful evaluation of Cu2+ ions content in various real sample with complicated matrices.
Multiwalled carbon nanotubes chemically functionalized with 2-((3-silylpropylimino) methyl) phenol (SPIMP-MWCNT) and successfully applied for the solid phase extraction (SPE) of some metal ions in ...food samples. The influences of the analytical parameters including pH, amounts of solid phase, eluent conditions (type, volume and concentrations), sample volume and interference of some metal ions on the recoveries of ions Cu²⁺, Pb²⁺, Fe²⁺, Ni²⁺ and Zn²⁺ ion were investigated. The metal ions retained on SPIMP-MWCNT was eluted using 6 mL of 4 mol L⁻¹ HNO₃ solution and their content was determined by flame atomic absorption spectrometry (FAAS) with recoveries more than 95% and relative standard deviations (n = 5) between 2.4–3.4% for both reproducibility and repeatability. The detection limit of this metal ions was between 1.0–2.6 ng mL⁻¹ (3Sb, n = 10) and their preconcentration factor was 100, while their loading capacity was above 32.9 mg g⁻¹ of SPIMP-MWCNT. The proposed method was successfully applied for the preconcentration and determination of analytes in different samples.
A simple and relatively fast approach for developing a solid phase extraction has been described and used for determination of trace quantities of some heavy and transition metal ions with sodium ...dodecyl sulfate (SDS)-coated poly vinyl chloride (PVC) modified with bis(2-hydroxyacetophenone)-1,4-butanediimine (BHABDI) ligand.
The adsorbed ions were stripped from the solid phase by 10
mL of 3
M nitric acid as eluent. The eluting solution was analyzed for metals content (cadmium, chromium, cobalt, copper, lead and zinc) by flame atomic absorption spectrometry (FAAS). The main factors such as pH, amount of ligand and PVC, amount and type of surfactant, and condition of eluting solutions on the sorption recovery of metal ions have been investigated in detail. The relative standard deviation was found in the range of 1.0–3.2% for 0.2
μg
mL
−1of metals ions. After optimization of the extraction condition and the instrumental parameters, a detection limit was found to be in the range of 1.2–3.1
μg
L
−1, with enrichment factor of 50 was achieved. The method was successfully applied for the determination of these metals contents in real samples with satisfactory results.
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