A novel proton transfer compound (a new molybdate salt) and its X-ray structure

A novel proton transfer compound (OHRNH3)22+(MoO4)2- (R = 2-methyl-1-propyl), derived from 2-amino-2-methyl-1-propanol and MoO2(acac)2, synthesized and characterized by 1H NMR, X-ray diffraction analysis, UV-Vis and FT-IR spectroscopy. The single crystal X-ray diffraction analysis revealed that intra- and intermolecular proton transfer from (MoO4H2) to (OHRNH2) results in the formation of a new molybdate salt that its fragments are connected through H-bonding and ion-pairing as shown in the X-ray crystal structure. This salt crystallizes in the space group P21/n P_1 of the monoclinic system, with four molecules per unit cell. The unit cell parameters are a = 13.6091(11) Å, b = 6.1049(5) Å, c = 17.0840(13) Å and β = 97.745(4)°. KEY WORDS: Proton transfer, Molybdate salt, X-ray structure, MoO2(acac)2, 2-Amino-2-methyl-1-propanol Bull. Chem. Soc. Ethiop. 2013, 27(1), 69-76.DOI: http://dx.doi.org/10.4314/bcse.v27i1.

Theoretical study on the structural effect of some organic compounds as corrosion Inhibitors on mild steel in acid media

A quantitative structure property relationship (QSPR) analysis of some organic compounds (imines or Schiff bases) is studied. The corrosion inhibition efficiencies of these imines have been studied by using AM1 (Austin model 1) Hamiltonian SCF-MO method and QSPR analysis. One of the most promising semiempirical methods for predicating geometries and electronic properties is AM1. The geometry of all compounds 1-11 was optimized and all data obtained for building the multiple regression model. The proposed equationswere applied to predict the corrosion inhibition efficiency of some related structures to select molecules of possible activity from a presumable library of compounds was obtained from the regression coefficients for themode

A novel proton transfer compound (a new molybdate salt) and its X-ray structure

A novel proton transfer compound (OHRNH3)22+(MoO4)2- (R = 2-methyl-1-propyl), derived from 2-amino-2-methyl-1-propanol and MoO2(acac)2, synthesized and characterized by 1H NMR, X-ray diffraction analysis, UV-Vis and FT-IR spectroscopy. The single crystal X-ray diffraction analysis revealed that intra- and intermolecular proton transfer from (MoO4H2) to (OHRNH2) results in the formation of a new molybdate salt that its fragments are connected through H-bonding and ion-pairing as shown in the X-ray crystal structure. This salt crystallizes in the space group P21/n P_1 of the monoclinic system, with four molecules per unit cell. The unit cell parameters are a = 13.6091(11) Å, b = 6.1049(5) Å, c = 17.0840(13) Å and β = 97.745(4)°.DOI: http://dx.doi.org/10.4314/bcse.v27i1.

Electron-topological, energetic and π-electron delocalization analysis of ketoenamine-enolimine tautomeric equilibrium

The ketoenamine-enolimine tautometic equilibrium has been studied by the analysis of aromaticity and electron-topological parameters. The influence of substituents on the energy of the transition state and of the tautomeric forms has been investigated for different positions of chelate chain. The quantum theory of atoms in molecules method (QTAIM) has been applied to study changes in the electron-topological parameters of the molecule with respect to the tautomeric equilibrium in intramolecular hydrogen bond. Dependencies of the HOMA aromaticity index and electron density at the critical points defining aromaticity and electronic state of the chelate chain on the transition state (TS), OH and HN tautomeric forms have been obtained

Some quantum chemical study on the structural properties of three unsymmetrical Schiff base ligands

In this studythree Schiff base ligands derived of 2-hydroxybenzaldehyde: H2L1, H2L2 and H2L3 have been subjected to theoretical studies by using density functional theory (DFT) calculations. The electronic properties such as highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO) energy, HOMO-LUMO gap energy, RHF energy, some of important bond lengths and angles, dipole moment and molecular densities have been investigated. Also the calculated IR spectra of these ligands are in good consistency with the experimental results. DOI: http://dx.doi.org/10.4314/bcse.v28i2.1

Theoretical study of ht-[(ph)Pt(μ-PN)(μ-NP)PtMe2](CF3CO2) structure as a heavy dimer complex and comparison of results with experimental X-ray data

DFT calculations performed using Amsterdam Density Functional (ADF 2009.01b) program to estimate best geometry of an unsymmetrical cationic organo-diplatinum complex containing two bridging 2-diphenylphosphinopyridine,(PN), ligands and a platinum-platinum donor–acceptor bond, ht-[(ph)Pt(μ-PN)(μ-NP)PtMe2](CF3CO2), as a moderately heavy dimer complex of platinum(II). The obtained geometry is in excellent agreement with the crystallographic data. Energy is in all cases about 12–15 kcal mol−1. For the LDA (XC potential in SCF) the DZ and TZ2P basis sets have been used. Furthermore, for the GGA(BLYP), GGA(BP) and GGA(PW91) method, the DZ basis set have been just used, due to the cost of calculations. The result showed that surprisingly the simple LDA(TZP) method has the minimum of energy, comparing the others. All the attempts for optimizing the mentioned dimer using B3LYP and OLYP methods failed

Magnetic nanomaterials based electrochemical (bio)sensors for food analysis

It is widely accepted that nanotechnology attracted more interest because of various values that nanomaterial applications offers in different fields. Recently, researchers have proposed nanomaterials based electrochemical sensors and biosensors as one of the potent alternatives or supplementary analytical tools to the conventional detection procedures that consumes a lot of time. Among different nanomaterials, researchers largely considered magnetic nanomaterials (MNMs) for developing and fabricating the electrochemical (bio)sensors for numerous utilizations. Among several factors, healthier and higher quality foods are the most important preferences of consumers and manufacturers. For this reason, developing new techniques for rapid, precise as well as sensitive determination of components or contaminants of foods is very important. Therefore, developing the new electrochemical (bio)sensors in food analysis is one of the key and effervescent research fields. In this review, firstly, we presented the properties and synthesis strategies of MNMs. Then, we summarized some of the recently developed MNMs-based electrochemical (bio)sensors for food analysis including detecting the antioxidants, synthetic food colorants, pesticides, heavy metal ions, antibiotics and other analytes (bisphenol A, nitrite and aflatoxins) from 2010 to 2020. Finally, the present review described advantages, challenges as well as future directions in this field. © 2021 Elsevier B.V

Fabrication of novel TiO2 nanoparticles/Mn(III) salen doped carbon paste electrode: application as electrochemical sensor for the determination of hydrazine in the presence of phenol

Hydrazine and phenol are two important environmental pollutants. In this work, an electrochemical sensor for the selective and sensitive detection of hydrazine in presence of phenol was developed by the bulk modification of carbon paste electrode (CPE) with TiO2 nanoparticles and Mn(III) salen. Large peak separation, good sensitivity, and stability allow this modified electrode to analyze hydrazine individually and simultaneously along with phenol. Applying square wave voltammetry (SWV), a linear dynamic range of 3 × 10(-8)-4.0 × 10(-4) M with detection limit of 10.0 nM was obtained for hydrazine. Finally, the proposed method was applied to the determination of hydrazine and phenol in some real samples

Recent developments in voltammetric and amperometric sensors for cysteine detection

This review article aims to provide an overview of the recent advances in the voltammetric and amperometric sensing of cysteine (Cys). The introduction summarizes the important role of Cys as an essential amino acid, techniques for its sensing, and the utilization of electrochemical methods and chemically modified electrodes for its determination. The main section covers voltammetric and amperometric sensing of Cys based on glassy carbon electrodes, screen printed electrodes, and carbon paste electrodes, modified with various electrocatalytic materials. The conclusion section discusses the current challenges of Cys determination and the future perspectives. © The Royal Society of Chemistry 2021

Performance of metal-organic frameworks in the electrochemical sensing of environmental pollutants

Environmental pollution has been a known threat to our world due to the rapid urbanization, changing lifestyle of people, and modern industrialization. Therefore, there is an urgent need to develop novel sensing approaches having promising performance with high reliability and sensitivity for the precise monitoring of various pollutants. Metal-organic frameworks (MOFs) have been intensively investigated by many researchers as electrode modifiers for electrochemical sensing due to their excellent properties and efficiency. Diverse MOF-based electrochemical sensing systems are applied for environmental analysis for the sensitive, rapid and cost-effective determination of various analytes because of their unique structures, and properties, including the tunable pore size, high surface area, high catalytic activity, and high density of active sites. The aim of this review article is to evaluate the application of MOFs in the electrochemical sensing of environmental pollutants including heavy metal ions, pesticides, phenolic compounds, nitroaromatic compounds, antibiotics, nitrite, and hydrazine. Current limitations and future directions for the application of MOF-based electrochemical sensors for the detection of environmental pollutants are discussed. © The Royal Society of Chemistry 2021