Interactions involved in the adsorption of ethylene glycol and 2-hydroxyethoxide on the Au(111) surface: a Density Functional Theory study.

Context: The monolayers of ethylene glycol and 2-hydroxyethoxide on gold surfaces have been used in hybrid materials as biosensors. In this article, the adsorption of ethylene glycol and 2-hydroxyethoxide on the Au(111) surface was analyzed. For the first system, ethylene glycol on Au(111), there are Au O and Au H interactions.

Computational tools to study non-covalent interactions and confinement effects in chemical systems.

Confinement is a very common phenomenon in chemistry, for example, when molecules are located inside cavities. In these conditions, the electronic structure of atoms and molecules is modified. These changes could be mapped through the interaction with other molecules since non-covalent interactions between molecules are also influenced by confinement.

Revealing the Role of Noncovalent Interactions on the Conformation of the Methyl Group in Tricyclic Orthoamide.

Tricyclic orthoamides are valuable molecules with wide-ranging applications, including organic synthesis and molecular recognition. Their structural properties make them intriguing, particularly the eclipsed all- conformer, which is typically less stable than the alternated conformation and is a rare phenomenon in organic chemistry. However, it gains stability in crystalline and hydrated settings, challenging the existing theoretical explanations.

Finite element method as an alternative to study the electronic structure of confined atoms.

The finite element method (FEM) based on a nonregular mesh is used to solve Hartree-Fock and Kohn-Sham equations for three atoms (hydrogen, helium, and beryllium) confined by finite and infinite potentials, defined in terms of piecewise functions or functions with a well-defined first derivative. This approach's reliability is shown when contrasted with Roothaan's approach, which depends on a basis set. Therefore, its exponents must be optimized for each confinement imposed over each atom, which is a monumental task.

Non-conventional interactions of N3 inhibitor with the main protease of SARS-CoV and SARS-CoV-2.

The extensive spread of COVID-19 in every continent shows that SARS-CoV-2 virus has a higher transmission rate than SARS-CoV virus which emerged in 2002. This results in a global pandemic that is difficult to control. In this investigation, we analyze the interaction of N3 inhibitor and the main protease of SARS-CoV and SARS-CoV-2 by quantum chemistry calculations.

Ionization of many-electron atoms by the action of two plasma models.

The Hartree-Fock equations for many-electron atoms embedded in a plasma medium are solved using two different plasma models: (a) Debye-Hückel screening (DHS) potential and (b) exponential cosine screened Coulomb (ECSC) potential. Roothaan's approach is implemented for these models after solving the inherent difficulties to evaluate integrals where screening appears explicitly. A corresponding computer code was developed using the method of global basis sets (GBS).

Identification of the preferential CO and SO adsorption sites within NOTT-401.

NOTT-401 was found to be a highly stable adsorbent for SO2 and CO with excellent cyclability and a straightforward regeneration at room temperature. Moreover, the preferential CO binding sites within the MOF material have been identified by experimental in situ DRIFT spectroscopy coupled with DFT and QTAIM calculations. Such preferential CO adsorption sites were correlated to identify the most significant SO2 interactions within NOTT-401.

New information of dopaminergic agents based on quantum chemistry calculations.

Dopamine is an important neurotransmitter that plays a key role in a wide range of both locomotive and cognitive functions in humans. Disturbances on the dopaminergic system cause, among others, psychosis, Parkinson's disease and Huntington's disease. Antipsychotics are drugs that interact primarily with the dopamine receptors and are thus important for the control of psychosis and related disorders.

Non-covalent interactions between sertraline stereoisomers and 2-hydroxypropyl-β-cyclodextrin: a quantum chemistry analysis.

Inclusion compounds formed between sertraline stereoisomers and β-cyclodextrin, and 2-hydroxypropyl-β-cyclodextrin, were analyzed by using quantum chemistry methods. The exploration of the potential energy surface was performed using chemical intuition and classical molecular mechanics. This approach delivered around 200 candidates for low energy adducts, which were optimized through the PBE0/6-31G(d,p) method, and after this process solvent effects were considered by the continuous solvent model.

Fluorometric detection of iodine by MIL-53(Al)-TDC.

The fluorescent properties of MIL-53(Al)-TDC are drastically changed due to the presence of iodine, even in small quantities, as a result of an energy transfer process from the host material (MIL-53(Al)-TDC) to the guest molecule (I). While MIL-53(Al)-TDC's emission spectrum shows a weak and broad band, after I adsorption, it exhibits well-resolved and long-lasting emission lines, which could be exploited for iodine detection. Density Functional Theory periodical calculations demonstrated that in the most stable MIL-53(Al)-TDCI configuration, the I molecule is bonded mainly by an O-HI hydrogen bond.

A detailed description of the CO molecule adsorbed in InOF-1.

CO is extremely toxic to humans since it can combine with haemoglobin to form carboxy-haemoglobin that reduces the oxygen-carrying capacity of blood. Metal-organic frameworks (MOFs), in particular InOF-1, are currently receiving preferential attention for the separation and capture of CO. In this investigation we report a theoretical study based on periodic density-functional-theory (DFT) analysis and matching experimental results (in situ DRIFTS).

Confined benzene within InOF-1: contrasting CO and SO capture behaviours.

The confinement of small amounts of benzene in InOF-1 (Bz@InOF-1) shows a contradictory behavior in the capture of CO2 and SO2. While the capture of CO2 is increased 1.6 times, compared to the pristine material, the capture of SO2 shows a considerable decrease.

A quantum chemical approach representing a new perspective concerning agonist and antagonist drugs in the context of schizophrenia and Parkinson's disease.

Schizophrenia and Parkinson's disease can be controlled with dopamine antagonists and agonists. In order to improve the understanding of the reaction mechanism of these drugs, in this investigation we present a quantum chemical study of 20 antagonists and 10 agonists. Electron donor acceptor capacity and global hardness are analyzed using Density Functional Theory calculations.

Confined toluene within InOF-1: CO capture enhancement.

The toluene adsorption properties of InOF-1 are studied along with the confinement of small amounts of this non-polar molecule revealing a 1.38-fold increase in CO capture, from 5.26 wt% under anhydrous conditions to 7.

Implementation of the Molecular Electrostatic Potential over Graphics Processing Units.

The molecular electrostatic potential (MEP) generated by quantum chemistry methods and Gaussian functions is evaluated over graphics processing units (GPUs). This implementation is based on full-range Rys polynomials with nodes and weights obtained in each thread of a GPU. For high angular moments, the corresponding integral is solved using a one-dimension vertical recurrence relation.

Relevance of hydrogen bonding in CO capture enhancement within InOF-1: an energy and vibrational analysis.

The enhancement of CO capture due to the confinement of polar molecules within InOF-1 was previously demonstrated. In particular, the presence of MeOH produced 1.30-fold increase in the total CO capture.

van der Waals exchange-correlation functionals over bulk and surface properties of transition metals.

The correct description of van der Waals (vdW) interaction forces is required for accurately describing dispersion bonded systems. Several approaches have been proposed to include London dispersion in density functional theory exchange-correlation functionals, where the family of so-called van der Waals (vdW-DF) exchange-correlation functionals have shown a better performance than local or semi local exchange-correlation functionals for describing molecular adsorption on metals. Despite the numerous benchmarks performed with these functionals, their performance in predicting bulk properties of transition metals has hitherto not been investigated in detail.

CO capture enhancement for InOF-1: confinement of 2-propanol.

The 2-propanol (i-PrOH) adsorption properties of InOF-1 are investigated along with the confinement of small amounts of this alcohol to enhance the CO2 capture for i-PrOH@InOF-1 (1.25-fold improvement compared to pristine InOF-1). InOF-1 exhibited a high affinity towards i-PrOH, experimentally quantified by ΔHads (-55 kJ mol-1), and DFT geometry optimisations showed strong hydrogen bonding between O(i-PrOH) and H(μ2-OH).

SBA15-Fluconazole as a Protective Approach Against Mild Steel Corrosion: Synthesis, Characterization, and Computational Studies.

A SBA15-Fluconazole composite (SBA15-Flu) was prepared to formulate a self-healing coating for mild steel. The composite was obtained by dispersing SBA15 in a methanolic solution containing Fluconazole (Flu). The materials were characterized by using different techniques.

Coordination numbers in hydrated Cu(II) ions.

The potential energy surface of [Cu(HO)] clusters with n = 12, 16, and 18 was explored by using a modified version of the simulated annealing method. Such exploration was carried out by using the PM7 semiempirical method to obtain around 100,000 isomers, which provide candidates to be optimized with PBE0-D3, M06-2X, and BHLYP exchange-correlation functionals coupled with the 6-311++G** basis set. These methods based on the Kohn-Sham approach delivered isomers with coordination numbers of 4, 5, and 6.

Analyzing ZnO clusters through the density-functional theory.

The potential energy surface of Zn O clusters (n = 2, 4, 6, 8) has been explored by using a simulated annealing method. For n = 2, 4, and 6, the CCSD(T)/TZP method was used as the reference, and from here it is shown that the M06-2X/TZP method gives the lowest deviations over PBE, PBE0, B3LYP, M06, and MP2 methods. Thus, with the M06-2X method we predict isomers of Zn O clusters, which coincide with some isomers reported previously.