Browsing by Author "Mollaamin, F, Monajjemi, M"

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    Application of DFT/TD-DFT Frameworks in the Drug Delivery Mechanism: Investigation of Chelated Bisphosphonate with Transition Metal Cations in Bone Treatment
    (2023-03-01) Mollaamin F., Monajjemi M.; Mollaamin, F, Monajjemi, M
    Carbon nanotubes (CNTs) are applied in a drug delivery system, which can be reacted with different structures such biomolecules. Bones have vital functions and are the locations of biochemical reactions in cells that might be exposed various diseases. As different metal ions are integral components of bone tissue with different functions in the physiological cellular medium as well as in bone treatment, they can be used differently as a basis or as a supplement for various materials in the field of bone repair. Therefore, this research aims to represent the recent progress in conjugated bisphosphonate (BP)-divalent transition metal ions of Mn2+, Fe2+, and Co2+ with an emphasis on the properties of interaction with a (6, 6) armchair carbon nanotube as a nanocarrier to exhibit the potential biomedical application of drug delivery. In this article, “CNT” linked to “BP“ of alendronic acid, ibandronic acid, neridronic acid, and pamidronic acid, which are chelated to transition metal cations of Mn2+, Fe2+, and Co2+, was investigated based on DFT insights for obtaining the electron charge density. Transition metals chelating with phosphonate groups, which are large with six O atoms with negative charges, are active in generating chelated complexes with the bisphosphonates [BPs- Mn2+/Fe2+/Co2+] through the status of drug design. In this work, B3LYP/6-311+G(d,p)/lanl2dz we have estimated the susceptibility of CNT for conjugating alendronic acid, ibandronic acid, neridronic acid, and pamidronic acid, which are chelated to transition metal cations of Mn2+, Fe2+, and Co2+ through NMR, NQR, IR, UV-VIS spectroscopy, and HOMO-LUMO analysis. Finally, the obtained results have confirmed that the possibility of applying CNT and BPs of alendronic acid, ibandronic acid, neridronic acid, and pamidronic acid becomes suitable in transition metal chelating for delivery application. The calculated HOMO–LUMO energy gaps for BPs of alendronic acid, ibandronic acid, neridronic acid, and pamidronic acid at the B3LYP/6-311+G (d,p) level have revealed that the energy gap reflects the chemical activity of the molecule.
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    Graphene Embedded with Transition Metals for Capturing Carbon Dioxide: Gas Detection Study Using QM Methods
    (2023-03-01) Mollaamin F., Monajjemi M.; Mollaamin, F, Monajjemi, M
    Carbon dioxide (CO2) adsorption on decorated graphene (GR) sheets with transition metals (TMs) including iron, nickel and zinc was investigated for removing this hazardous gas from the environment. TM-doped GR results in higher activity toward gas detecting than pristine graphene nanosheets. TM embedding restrains hydrogen evolution on the C sites, leaving more available sites for a CO2 decrease. The Langmuir adsorption model with ONIOM using CAM-B3LYP functional and LANL2DZ and 6-31+G (d,p) basis sets due to Gaussian 16 revision C.01 program on the complexes of CO2→(Fe, Ni, Zn) embedded on the GR was accomplished. The changes of charge density illustrated a more considerable charge transfer for Zn-embedded GR. The thermodynamic results from IR spectroscopy indicated that (Formula presented.) has the notable gap of Gibbs free energy adsorption with a dipole moment which defines the alterations between the Gibbs free energy of the initial compounds ((Formula presented.) and (Formula presented.)) and product compound ((Formula presented.)) through polarizability. Frontier molecular orbital and band energy gaps accompanying some chemical reactivity parameters represented the behavior of molecular electrical transport of the (Fe, Ni, Zn) embedding of GR for the adsorption of CO2 gas molecules. Our results have provided a favorable understanding of the interaction between TM-embedded graphene nanosheets and CO2.
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    Molecular modelling framework of metal-organic clusters for conserving surfaces: Langmuir sorption through the TD-DFT/ONIOM approach
    (2023-01-01) Mollaamin F., Monajjemi M.; Mollaamin, F, Monajjemi, M
    The Langmuir adsorption model of some organic inhibitors containing benzotriazole (BTA), 8- hydroxyquinoline (8-HQ), and 2-mercaptobenzothiazole (2-MBT) onto the Al-X (X=Mg, Ga, Si) alloy surface.The ONIOM method has been accomplished with a three-layered step of high level of DFT method using EPR-III, 6-31+G (d,p) and LANL2DZ basis sets. NMR spectroscopy has indeed concentrated on the Al shielding in the intra-atomic interaction with Mg, Ga and Si and meanwhile interatomic interaction with other atoms in BTA, 8-HQ, and 2-MBT compounds. Aluminum-silicon binary alloy with highest changes in the shielding tensors of NMR spectrum produced by intra-atomic interaction directs us to the most penetration in the neighbor atoms created by interatomic reaction. IR computations based on comparing the amounts has exhibited that 2-MBT with high stability based on its active zone of sulfur atoms and high molecular size shows high corrosive inhibition as 2-MBT →Al-Ga>Al-Mg ≈ Al-Si. Furthermore, BTA with nitrogen atom and 8-HQ with oxygen atom can coat the Al-X (X=Mg/Ga/Si) alloys surface through Langmuir adsorption as BTA →Al-Ga>Al-Mg ≈ Al-Si, and 8-HQ →Al-Ga>Al-Mg ≈ Al-Si, respectively. Moreover, it has been observed that the inhibition yield is ordered as: Al-Ga> Al-Mg ≈ Al-Si.
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    Tailoring and functionalizing the graphitic-like GaN and GaP nanostructures as selective sensors for NO, NO, and NH adsorbing: a DFT study.
    (2023-05-06T00:00:00Z) Mollaamin, Fatemeh, Monajjemi, Majid; Mollaamin, F, Monajjemi, M
    Langmuir adsorption of gas molecules of NO, NO, and NH on the graphitic GaN and GaP sheets has been accomplished using density functional theory. The changes of charge density have shown a more important charge transfer for GaN compared to GaP which acts both as the electron donor while gas molecules act as the stronger electron acceptors through adsorption on the graphitic-like GaN surface. The adsorption of NO and NO molecules introduced spin polarization in the PL-GaN sheet, indicating that it can be employed as a magnetic gas sensor for NO and NO sensing.
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    Transition metal (X = Mn, Fe, Co, Ni, Cu, Zn)-doped graphene as gas sensor for CO and NO detection: a molecular modeling framework by DFT perspective.
    (2023-03-29T00:00:00Z) Mollaamin, Fatemeh, Monajjemi, Majid; Mollaamin, F, Monajjemi, M
    In this research, CO and NO 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 CO adsorption and a more remarkable charge transfer for Co-doped C-NG through NO 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 [Formula: see text] values are almost similar for doped metal transitions of Mn, Co, and Cu on the C-NG nanosheet, while [Formula: see text] has the largest gap of Gibbs free energy adsorption with dipole moment.