Synthesis of N2, N6-bis(5-methylthiazol-2-yl)pyridine-2,6-dicarboxamide fluoroscent sensor for detection of Cu2+ and Ni2+ Ions

This article reports an amide based Chemosensor used for selective detection of divalent Cu+2 and Ni+2 ions via Fluorescence turn off. The selective sensing ability of Chemosensor was investigated in presence of different metal ions Mg2+, Ag+, Fe2+, K+, Cu2+, Ni2+, Hg2+, Pb2+, Mn2+, Pd2+, Cd2+ and Mn3+ as competitive ions. The receptor i. e. Chemosensor formed complexes with metal ions in 1:1 stoichiometric ratio. The detection limit and binding constant calculated as 1.92×10–4 and 1.4×10–4 M and 2.16×103 M−1 and 3.09×103 M−1 for Cu2+ and Ni2+ions respectively. The complexes were characterized by UV/visible, FT-IR, 13C NMR and 1H NMR spectroscopy. Further the structure and Crystallinity were calculated by P-XRD spectral analysis. The crystallinity found to be 65.27 and 67.87% respectively

Complexation of eriochromcyanine R with aluminum and iron (III) ions in the presence of sufractants

The effect of various types of surfactants on the complexation of aluminum and iron (III) ions with eriochromecyanine R have been studied. According to the light absorption spectra of the dye and complexes with metal ions without surfactants and in the presence of catamine AB, oxyphos B, and syntanol DS-10 at various pH and the concentration of surfactants determined the optimal conditions for complexation have been determined. Oxyphos B has a negative effect on the spectrophotometric characteristics of the complexes. Syntanol DS-10 has practically no effect. The presence of catamine AB causes a bathochromic shift in the maximum of light absorption of the complex, increases the contrast of the photometric reaction and the value of the extinction coefficient. The composition of the complexes in the absence and in the presence of catamine AB has been determined by saturation and isomolar series methods. The presence of catamine AB increases the molar ratio of metal: reagent in the complex from 1: 2 to 1: 3. By Babko's method, conditional stability constants of the complexes have been determined, calibration curves have been constructed, and molar light absorption coefficients have been calculated.

Influence of surfactances on the spectrophotometric characteristics of scandium complexes with eriochromcianine R

The effect of various types of surfactants on the complexation of scandium ions with eriochromecyanine R. The optimal conditions were determined from the light absorption spectra of the dye and complexes with metal ions without surfactants and in the presence of catamine AB, oxyphos B and syntanol DS-10 at various pH values and surfactant concentrations complexation. The presence of catamine AB causes a bathochromic shift in the maximum of light absorption of the complex, increases the contrast of the photometric reaction and the value of the extinction coefficient. The composition of the complexes in the absence and in the presence of catamine AB was determined by saturation and iso- molar series methods. It also increases the molar ratio of Sc : eriochromecyanine R in the complex from 1:2 to 1:3. The conditional stability constants of the complexes were determined by Babko's method, calibration curves were constructed, and the coefficients of molar light absorption were calculated. Oxyphos B has a negative effect on the spectrophotometric characteristics of the complexes. Syntanol DS-10 has practically no effect.

Study on conformational search of new thiosemicarbazone reagent and complexes with metal ions integrating semi-empirical quantum and molecular mechanics calculation and Monte Carlo simulation

In this study, the conformational analysis of the ML2 complexes of new thiosemicarbazone reagents with metal cations Cd2+, Ni2+, Cu2+, Hg2+, Pb2+, Mn2+ and Zn2+ is to find the conformations with the most suitable energy of the whole molecular system. The search method incorporates MM+ and PM3 calculations with Monte Carlo techniques using the Metropolis algorithm in terms of T = 298K to 473K. The initial selection conformation was done randomly after 15 repeatable conformations and 30 conformations rejected. The conformations are chosen to change by changing the torsional-dihedral angle at the position of the metal cation associated with the donor atoms N and S of thiosemicarbazone reagents. The search method is performed by random changes of the dihedral angles to create new structures and then minimize the energy for each of these angles using molecular mechanics. The unique low energy suitability is stored while high or duplicate energy structures are discarded.

Voltammetric Tracing of Al(III) Using Supramolecular Metal-Polyphenolic Nanofilms Obtained via Electrochemically Assisted Self-Assembly

Supramolecular metal-polyphenolic thin sensor films represent a unique class of composite materials. Their properties and sensitivity can be easily modified via controlled self-assembly of their molecular components. Among the different assembly methods, electrochemically triggered processes are extremely powerful because they allow spatial confinement of the film buildup via an electrical stimuli-controlled process. In this article, an approach to employ the electrochemically assisted self-assembly of a multicomponent supramolecular film based on a naturally occurring polyphenol, tannic acid (TA), is featured. Here, the capacity of polyphenolic compounds to form complexes with metal ions, as well as to act both as reducing agents and stabilizers in colloidal synthesis of metal nanoparticles (NPs) is utilized. The electrochemically triggered self-assembly can be coupled with the ion – printing method, in which the targeted metal ion, in this case Al(III), is incorporated into the film during the synthesis and chemically removed afterwards. This procedure results in a template-like structure of the film with openings ready to bind the same metal ion from the probed solution, thus significantly improving the selectivity of the sensor formed and enhancing its applicability for sensing of toxic metal ions in complex aqueous solutions, such as physiological fluids.

N,N’-Bis(salicylidene)ethylenediamine (Salen) as an Active Compound for the Recovery of Ni(II), Cu(II), and Zn(II) Ions from Aqueous Solutions

In this paper, three main methods of metal ion separation, i.e., liquid–liquid extraction, transport across polymer inclusion membranes (PIMs), and sorption/desorption, are described. In all of them, N,N’-bis(salicylidene)ethylenediamine (salen) was used as an active compound, i.e., as an extractant or as a carrier for the recovery of Ni(II), Cu(II), or Zn(II) ions from aqueous solutions. In each case, the recovery was performed on a model solution, which contained only a single metal ion. The obtained results were compared with the author’s previous results for the separation of metal ions using β-diketones, since both β-diketones and salen form the so-called Werner-type complexes. Electrospray ionization high-resolution mass spectrometry (ESI-HRMS) was also applied to confirm the ability of the carrier to form complexes with metal ions in a solution. Moreover, spectrophotometry was used to determine the stability constant of the obtained complexes.

Chelate chemistry governs ion-specific stiffening of Bacillus subtilis B-1 and Azotobacter vinelandii biofilms

Depending on the main polymer component of the biofilms studied, chelate complexes with metal ions can be formed that entail an increase in biofilm stiffness.

Production of Zol-Gel Pasta in the Complex System ВаСl2-SrCl2-Sb2О3 Based on Lemonic Acid and Н2О at Temperature Interval 40-42 °С

The article investigated the preparation of sol-gel paste from many component substances barium chloride (BaCl2), strontium chloride (SrCl2), antimony trioxide (Sb2O3), citric acid in a liquid medium by the complexometric (chelate) method. During the reaction, the pH of the medium was 5.5 units, temperature conditions 40–42 °C. For efficient complex formation, an electric mixer was used. The ratio of multicomponent substances was according to the following formula BaIx ∙ SrIx ∙ SbIx ∙ CAIx (where X = I:I:I:I). This reaction was studied, complexes with metal ions. Thus, the sol-gel process includes hydrolysis at temperature conditions, and the mechanical effects of the latter processes occur during further polymerization and a viscous resin (gel) is formed. A homogeneous white paste is obtained, which is nanosubstances.

Enhancing the Solubility of Curcumin Metal Complexes and Investigating Some of Their Biological Activities

This article describes the synthesis of curcumin complexes with metal ions. Properties of these complexes such as spectra IR and UV-Vis and solubility were investigated. The optimum parameters of ultrasound to enhance the solubility was figured out as follows: the capacity of ultrasound: 750 W/g; the time of ultrasound: 7 min; the concentration of the surfactant Tween 80 : 2%. The maximum solubility (mg/ml) of complexes was as follows: Cur-Fe(III): 0.162 ± 0.01; Cur-Zn(II): 0.267 ± 0.02; and Cur-Ca(II): 0.417 ± 0.05. Antioxidant capacity (DPPH, %I) of curcumin complexes was higher than that of curcumin-free complexes. All of these curcumin complexes revealed antimicrobial activities, in which calcium complex had the best resistance against Salmonella, followed by Fe(III) complexes. Meanwhile, the zinc complex was not resistant to this bacterium. These complexes showed antibacterial activity on Staphylococcus aureus, in which Cur-Ca (II) complexes had the highest antibacterial activity. For Escherichia coli, the Cur-Zn (II) complex had no resistance, while the Cur-Ca (II) complex showed the highest antibacterial activity.