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A new biomimetic sensor (BS) has been prepared by modifying the carbon paste electrode (CPE) based on [Fe(NTB)Cl2]Cl·EtOH (FeC) {NTB = tris(2‐benzimidazolylmethyl)amine} for the electrochemical detection of acrylamide (AA). The development of the reported BS was focused on the creation of an AA with α‐NH2 group of N‐terminal valine of hemoglobin (HG), which reduces the peak current of HG‐Fe+3 reduction. The fabricated BS was characterized by scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV), as well as square wave voltammetry (SWV) for studying the electrochemical properties of AA on its surface. Under optimized conditions, the BS was applied for the direct determination of AA in two linear concentration ranges: 1.0 × 10−6 and 1.0 × 10−4 M. The first linear was observed from 1.0 × 10−6 to 1 × 10−5 M with a limit of detection (LOD) of 1.465 × 10−7 M, while the second linear part was detected from 1.0 × 10−5 to 1 × 10−4 M with LOD of 5.67 × 10−6 M. Finally, the constructed BS was successfully applied for the evaluation of AA in various potato chips, and the results were comparable to those obtained from other electrochemical methods. The density functional theory (DFT) could successfully explain the recognition process of acrylamide, that is, the hydroamination of the alkene group of acrylamide by imidazole moiety of the iron complex. [ABSTRACT FROM AUTHOR]

The molecular complexes between thiobarbituric acid (TBA) and halogen molecules (X2 = I2, Br2, and Cl2) in different solvents are explored. Density functional theory (DFT) calculations at rwb97xd/lanl2dz were used to corroborate the experimental electronic and optical properties of the molecular adducts. Experimental results (Fourier transform infrared spectroscopy) show the stability of the complexes by halogen bonding (XB) and competitive hydrogen bonding (HB), which was supported by the DFT calculations. The molecular electrostatic potential and the frontier orbital calculations supported engagement of the thione group in XB rather than the carbonyl group. Based on the Hirshfeld atomic population, noncovalent interaction, and natural bond orbital analysis, the stability of TBAX2 adducts increases in the order TBACl2 > TBABr2 > TBAI2, where the larger charge transfer and highest stabilization energy were calculated for TBACl2 adducts. [ABSTRACT FROM AUTHOR]

Within the framework of the present study, a polydentate ligand with S and N donor sites along with its CuII‐based chelates were prepared and characterized. Elemental and thermal analyses, μeff and ΛM measurements as well as spectroscopy techniques including FT‐IR, electronic spectra, and EPR are the characterization tools. Computational chemistry calculations were applied to confirm the geometrical assignments of the penta and hexa coordinated perchlorato and chloro derivatives, respectively. Octahedral and trigonal bipyramidal stereochemistries were assigned for these copper(II) chelates. Powder X‐ray spectroscopy data were processed by Expo 2014 computer program for the structural illustration of one of the existing octahedral metal complexes. Biomimicking of copper(II) containing proteins phenoxazinone synthase and catechol oxidase was studied and the obtained results demonstrated promising oxidase‐like activity of the present CuII‐base complexes. Kinetic measurements were also performed to identify the potential catalytic pathways of the studied oxidation processes. The type of the counter‐anion included in the complexes significantly controls the structural features and the catalytic properties. [ABSTRACT FROM AUTHOR]