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The electronic, magnetic, and thermodynamic properties of alkali/alkaline earth metal ion‐adsorbed gallium nitride nanocage (Ga5N10_NC) have been investigated using density functional theory. The results denote that alkali/alkaline earth‐metal ion‐adsorbed Ga5N10_NC systems are stable compounds, with the most stable adsorption site being the center of the cage ring. The partial density of states (PDOS) can estimate a certain charge assembly between Li+, Na+, K+/ Be2+, Mg2+, Ca2+ and Ga5N10_NC which indicate the complex dominant of metallic features as: Ca2+ > Mg2+ > Be2+ >> K+ > Na+ > Li+. For confirmation of magnetic‐alignment of Ga5N10_NC, monovalent (M+) and divalent (M2+) metal ions were added to the sample to measure the effects of metals on the magnetic‐alignment properties of Ga5N10_NC. Furthermore, the reported results of NMR spectroscopy have exhibited that both M+ and M2+ can be optimized to achieve optimal alignment of nanocage in the presence of an applied magnetic field; however, chemical shift anisotropy spans for Ca2+– and Mg2+–containing samples is due to Ca2+ and Mg2+ ions binding to Ga5N10_NC. Regarding IR spectroscopy, Li+@ Ga5N10_NC and Be2+@ Ga5N10_NC with more electronegativity appear the most fluctuations through adsorption process. Moreover, based on NQR analysis, Ca2+ has shown a different graph of electric potential during trapping in Ga5N10_NC compared to other metal cations. Based on the results of ∆GRo$$ \Delta {G}_R^o $$ amounts in this research, the selectivity of metal ion adsorption by gallium nitride nanocage (ion sensor) has been approved as: K+>Na+> Li+ in alkali metals and Ca2+>Mg2+> Be2+ in alkaline earth metals. [ABSTRACT FROM AUTHOR]

Aluminum alloys with magnesium are broadly applied as structural materials for their high ductility and remarkable corrosion resistance. As the strongest alloys of this system have low stability specifications, the present research aims to investigate the probability of making strong of Al–Mg alloy by doping silicon, germanium and tin. This work presents an analysis of the influence of some organic heterocyclic inhibitors owing to Langmuir adsorption and DFT and TD-DFT method with different process parameters, on the corrosion resistance of aluminum alloy containing Al-X–Y (X = Mg, Y = Si, Ge, Sn). The ONIOM approach has been performed with a three-layered level of high by CAM-B3LYP theoretical function using 6–31 + G (2d,p) and LANL2DZ basis sets applying Gaussian 16 revision C.01; a medium semi-active part that consists of essential electronic contributions; and a low level part that has been handled using MM2 force field approaches. The physicochemical properties of inhibitor → metal alloy complexes are evaluated with the Langmuir adsorption through NMR, NBO, UV–VIS, HOMO/LUMO and DOS/PDOS graphs toward structural, electronic and thermodynamic properties and other quantum attributes. The fluctuation of occupancy of natural bond orbitals has been estimated for [pyridine,2-picoline,3-picoline,4-picoline, 2,4-lutidine → Al–Mg–(Si, Ge, Sn)] concerning the influence of nitrogen atom in the benzene ring of related heterocyclic compounds becoming close to the monolayer nanosurface of Al-X–Y (X = Mg, Y = Si, Ge, Sn) alloys. Furthermore, the results of partial electron density states (PDOS) have confirmed an obvious charge accumulation between the Al–Mg alloy and doped atoms of Si, Ge, and Sn through the recognition of the conduction band region. Based on the computed values of UV–VIS spectrums for pyridine, 2-picolone, 3-picoline, 4-picoline and 2,4-lutidine adsorbed on the Al–Mg-Y (Y = Si/Ge/Sn) alloys surface, there are maximum adsorption band wavelengths between 1000 nm and 4000 nm, respectively. In addition, it has been observed the sharpest peak in 2250 nm for all of these inhibitors adsorbed on the Al–Mg-Y (Y = Si/Ge/Sn) alloys surface. This study revealed that appropriate control of the coating process by Langmuir adsorption can illustrate inhibiting the aluminum alloys corrosion through an investigation of their structural, electronic and thermodynamic properties. [ABSTRACT FROM AUTHOR]

In this study, we investigated the abilities of nitrogen and sulfur heterocyclic carbenes of benzotriazole, 2-mercaptobenzothiazole, 8-hydroxyquinoline, and 3-amino-1,2,4-triazole-5-thiol regarding adsorption on an Al-Mg-Si alloy toward corrosion inhibition of the surface. Al-Si(14), Al-Si(19), and Al-Si(21) in the Al-Mg-Si alloy surface with the highest fluctuation in the shielding tensors of the "NMR" spectrum generated by intra-atomic interaction directed us to the most influence in the neighbor atoms generated by interatomic reactions of N → Al, O → Al, and S → Al through the coating and adsorbing process of Langmuir adsorption. The values of various thermodynamic properties and dipole moments of benzotriazole, 2-mercaptobenzothiazole, 8-hydroxyquinoline, and 3-amino-1,2,4-triazole-5-thiol adsorbed on the Al-Mg-Si increased by enhancing the molecular weight of these compounds as well as the charge distribution between organic compounds (electron donor) and the alloy surface (electron acceptor). Finally, this research can build up our knowledge of the electronic structure, relative stability, and surface bonding of various metal alloy surfaces, metal-doped alloy nanosheets, and other dependent mechanisms such as heterogeneous catalysis, friction lubrication, and biological systems. [ABSTRACT FROM AUTHOR]

Context: In this research, CO2 and NO2 adsorption on doped nanographene (NG) sheets with transition metals (Fe, Ni, Zn) and (Mn, Co, Cu), respectively, have been applied for scavenging of these toxic gases as the environmental pollutants. The values of changes of atomic charge density have illustrated a more significant charge transfer for Ni-doped C-NG through CO2 adsorption and a more remarkable charge transfer for Co-doped C-NG through NO2 adsorption. The data of NMR spectroscopy has depicted several fluctuations around the graph of Zn-doped on the nanographene surface. The thermodynamic results from IR spectroscopy have indicated that Δ G ads , NO 2 → TM @ C - NG o values are almost similar for doped metal transitions of Mn, Co, and Cu on the C-NG nanosheet, while Δ G ads , CO 2 → TM @ C - NG o has the largest gap of Gibbs free energy adsorption with dipole moment. Methods: The Langmuir adsorption model with a three-layered ONIOM using CAM-B3LYP functional accompanying LANL2DZ, EPR-III and 6-31 + G (d,p) basis sets due to Gaussian 16 revision C.01 program on the complexes of CO2 → (Fe, Ni, Zn) and NO2 → (Mn, Co, Cu) doped on the C-NG has been accomplished. Then, NMR and IR spectroscopy, nuclear quadrupole resonance, and natural bond orbital analysis have been accomplished for evaluating chemical shielding tensors, thermodynamic properties, electric potential, and occupancy fluctuation through bond orbitals, respectively. In addition, frontier orbitals of LUMO, HOMO, and also a series of chemical reactivity parameters have been calculated. Finally, time-dependent-DFT method due to UV-VIS spectrums has been accomplished to discern the low-lying excited states of CO2 and NO2 adsorption on the (Fe, Ni, Zn) and (Mn, Co, Cu), respectively, doped C-NG sheet. [ABSTRACT FROM AUTHOR]

[Display omitted] • The electronic, magnetic and thermodynamic properties of adsorption of toxic gases including NO molecules by using transition metals of X (X = Sc, V, Cr, Co, Cu, Zn)-doped boron nitride nanocage (B 5 N 10 _NC) have been investigated using density functional theory. • The results denote that NO@X–B 4 N 10 _NC are stable compounds, with the most stable adsorption site being the center of the cage ring. • The partial density of states (PDOS) can evaluate a determined charge assembly between gas molecules and X–B 4 N 10 _NC which indicates the competition among dominant complexes of Sc, V, Cr, Co, Cu, Zn. • NMR spectroscopy have exhibited that the yield of electron accepting for doping atoms on the X–B 4 N 10 _NC through gas molecules adsorption can be ordered as: Co≈Cr ˃ Cu ˃Zn > V≈SC that exhibits the strength of covalent bond between scandium, vanadium, chromium, cobalt, copper, zinc and NO towards toxic gas removal from air. • Regarding IR spectroscopy, doped nanocages of Sc–B 4 N 10 _NC, V–B 4 N 10 _NC, Cr–B 4 N 10 _NC, Co–B 4 N 10 _NC, Cu–B 4 N 10 _NC and Zn–B 4 N 10 _NC, respectively, have the most fluctuations and the highest adsorption tendency for gas molecules which can address specific questions on the individual effect of charge carriers (gas molecule-nanocage), as well as doping atoms on the overall structure. • High selectivity of atom-doped on boron nitride nanocage (gas sensor) for gas molecules adsorption has been resulted as: Cu≫Co > Cr > V > Zn > Sc. This article wants to denote that substituting boron atoms in pristine B 5 N 10 _NC with transition metals (dopants) of X = Sc, V, Cr, Co, Cu, Zn as electron acceptors can be more efficient for NO adsorption. The partial density of states (PDOS) can evaluate a determined charge assembly between gas molecules and X–B 4 N 10 _NC which indicates the competition among dominant complexes of Sc, V, Cr, Co, Cu, Zn. Based on NQR analysis, X −doped on B 5 N 10 _NC has shown the lowest fluctuation in electric potential and the highest negative atomic charge including 0.3710 (Cu), 0.5970 (Cr), 0.7392 (V), 0.7768 (Zn) and 0.8259 C (Sc), respectively, have presented the most tendency for being the electron acceptors. electron localization function (ELF) results have explained that a wider connected area occupied by an isosurface map for X–B4N10_NC, means that electron delocalization in these compounds is easier than pristine B5N10_NC. NMR graphs have shown that doping with all considered metals reduces substantially the band gap of pristine B 5 N 10 _NC. Cr-doped or Co-doped B 5 N 10 _NC can be ferromagnetic with high fluctuation in chemical shift, while Sc-doped or V-doped B 5 N 10 _NC may consider antiferromagnetic. The trapping of NO molecules by X– B 4 N 10 _NC were successfully incorporated due to binding formation consisting of N → Sc, N → V, N → Cr, N → Co, N → Cu, N → Zn. Regarding charge density difference, Sc and Cr have shown respectively the most and the least tensity for electron accepting as dopants during NO adsorption. Thermodynamic parameters have demonstrated that the maximum efficiency of Sc, V, Cr, Co, Cu, Zn atoms doping of B 5 N 10 _NC for gas molecules adsorption depends on the covalent bond between NO molecules and X–B 4 N 10 _NC as a potent sensor for air pollution removal. Finally, high selectivity of atom-doped on boron nitride nanocage (gas sensor) for gas molecules adsorption has been resulted as: Cu≫Co > Cr > V > Zn > Sc. [ABSTRACT FROM AUTHOR]

One of the applications of nanotechnology is use of carbon nanotubes for the targeted delivery of drug molecules. To demonstrate the physical and chemical properties of biomolecules and identify new material of drug properties, the interaction of carbon nanotubes (CNTs) with biomolecules is a subject of many investigations. CNTs is a synthetic compound with extraordinary mechanical, thermal, electrical, optical, and chemical properties widely applied for technological purposes. In this article we have tried to investigate thermodynamic parameters and dielectric effects in different solvents for one of the most famous anticancer drug 'cisplatin' combined to SWCNT, by Monte Carlo and density functional theory (DFT) calculations. Cause of platinum element in cisplatin we have done calculations as Gibbs free energy, thermal enthalpy, thermal energy and entropy at 6-31G** basis set with SCRF model of solvent. In this work, the major point has been embedded that results of both two methods of Monte Carlo and DFT can overlap with each other and cisplatin- SWCNT is a suitable compound for drug delivery in different media. [ABSTRACT FROM AUTHOR]

Abstract: In this work, the ternary mixed electrolyte system (CoCl2 +CoSO4 +H2O) was investigated based on the Pitzer ion-interaction model by using the potentiometric technique at T =298.15K. The mean activity coefficients of CoCl2 in the mixed aqueous electrolyte system were determined on the galvanic cell without liquid junction of the type: Co-ISE|CoCl2 (mA ), CoSO4 (mB ), H2O|Ag/AgCl over total ionic strengths from (0.001 to 6.000)mol·kg−1 for different series of salt ratio r ( and pure). The PVC based cobalt ion-selective electrode (Co-ISE) and the Ag/AgCl electrode used in this work were made in our laboratory and had a reasonably good Nernst response. The experimental results obeyed the Harned rule, and the Pitzer model could be used to describe this ternary system satisfactorily. Furthermore, the parameters obtained with the Pitzer model were used to calculate the values of the mean activity coefficients of CoSO4, the osmotic coefficients of water (ϕ) and the excess Gibbs free energies of solution (GE ) for the whole series of the studied electrolyte systems. [Copyright &y& Elsevier]

Abstract: In this research, thermodynamic properties of the ternary electrolyte system (MgCl2 +Mg(NO3)2 +H2O) were investigated using a potentiometric method. The galvanic cell used had no liquid junction of type: Mg-ISE|MgCl2 (m A), Mg(NO3)2 (m B), H2O|Ag/AgCl. The measurements were performed at T =298.15K and at total ionic strengths from 0.001 to 8.000mol/kg for different series of salt ratios =1.00, 2.50, 5.00, 7.50, 10.00 and 15.00. The PVC based magnesium ion-selective electrode (Mg-ISE) and the Ag/AgCl electrode used in this work were prepared in our laboratory and showed a reasonably good Nernst response. The Pitzer ion interaction model and Harned rule were used to illustrate the ternary electrolyte system investigated. The experimental results showed that both Pitzer model and Harned rule were suitable to be used satisfactorily to describe this ternary system. [ABSTRACT FROM AUTHOR]