Elucidating the Photophysics and Nonlinear Optical Properties of a Novel Azo Prototype for Possible Photonic Applications: A Quantum Chemical Analysis.

The photophysics and nonlinear optical responses of a novel nitrothiazol-methoxyphenol molecule were investigated using density functional theory (DFT) and time-dependent density functional theory (TD-DFT) methods with the polarizable continuum model to take the solvent effect into account. Special attention is paid to the description of the lowest absorption band, characterized as a strong π → π* state in the visible region of the spectrum. The TD-DFT emission spectrum analysis reveals a significant Stokes shift of more than 120 nm for the π → π* state in gas phase condition.

A DFT study of the effect of hydrostatic pressure on the structure and electronic properties of sarcosine crystal.

Context: We perform density functional theory calculations to study the dependence of the structural and electronic properties of the amino acid sarcosine crystal structure on hydrostatic pressure application. The results are analyzed and compared with the available experimental data. Our findings indicate that the crystal structure and properties of sarcosine calculated using the Grimme dispersion-corrected PBE functional (PBE-D3) best agree with the available experimental results under hydrostatic pressure of up to 3.

Exploring the molecular solvatochromism, stability, reactivity, and non-linear optical response of resveratrol.

Context: This work analyzes the isomerization effects and solvent contributions to the stability, electronic excitations, reactivity, and non-linear optical properties (NLO) of resveratrol molecules within the formalism of the Density Functional Theory. The findings suggest that resveratrol solvatochromism is significantly influenced by solvent polarization. The electronic and free energies (E and G) indicate that trans is the most stable conformer.

Role of the Solvent and Intramolecular Hydrogen Bonds in the Antioxidative Mechanism of Prenylisoflavone from Leaves of .

This work discusses the electron structure, antioxidative properties, and solvent contribution of two new antioxidant molecules discovered, named and , extracted from a medicinal plant called , found in the Amazon rain-forest. To gain a better understanding, a study using density functional theory coupled with the polarizable-continuum model and the standard 6-311++G(d,p) basis set was conducted. The results indicate that has a higher antioxidant potential than , confirming the experimental expectations.

SARS-CoV-2 external structures interacting with nanospheres using docking and molecular dynamics.

Coronavirus is caused by the SARS-CoV-2 virus has shown rapid proliferation and scarcity of treatments with proven effectiveness. In this way, we simulated the hospitalization of carbon nanospheres, with external active sites of the SARS-CoV-2 virus (M-Pro, S-Gly and E-Pro), which can be adsorbed or inactivated when interacting with the nanospheres. The computational procedures performed in this work were developed with the SwissDock server for molecular docking and the GROMACS software for molecular dynamics, making it possible to extract relevant data on affinity energy, distance between molecules, free Gibbs energy and mean square deviation of atomic positions, surface area accessible to solvents.

Biotransformation of 1-nitro-2-phenylethane [Formula: see text] 2-phenylethanol from fungi species of the Amazon biome: an experimental and theoretical analysis.

Context: Natural products and their biotransformation procedures are a powerful source of new chromophores with potential applications in fields like biology, pharmacology and materials science. Thus, this work discusses about the extraction procedure of 1-nitro-2-phenylethane (1N2PE) from Aniba canelilla, its biotransformation setup into 2-phenylethanol (2PE) using four fungi, Lasiodiplodia caatinguensis (phytopathogenic fungus from Citrus sinensis), Colletotrichum sp. (phytopathogenic fungus from Euterpe oleracea), Aspergillus flavus and Rigidoporus lineatus isolated from copper mining waste located in the interior of the Brazilian Amazon.

The Solute Polarization and Structural Effects on the Nonlinear Optical Response of Based Chromone Molecules.

The solute polarization due to solvent is a an electrostatic quantum effect that impacts diverse molecular properties, including the nonlinear optical response of a material. An iterative procedure that allows updating the solute charge distribution in the presence of the solvent is combined with a sequential Monte Carlo/Quantum Mechanics methodology and Density Functional Theory methods to evaluate the nonlinear optical (NLO) response using the hyper Rayleigh scattering (HRS) of a series of chromones recently identified in Chamaecrista diphylla, an herbaceous plant abundant throughout the Americas and used in folk medicine. From this study, it is determined that from gas to solvent environment, the systems acquire low refractive index (n) and an improvement of the first hyperpolarizability (β ), signaling potential NLO uses.

The Importance of the Density Functional Theory Exchange-Correlation Hartree-Fock Term in Magnetic Resonance: Application to an Aqueous Environment.

Within the framework of Density Functional Theory (DFT), the relevance of the term Hartree-Fock exchange (HFE) for a variety of molecular properties is a critical point. For this reason, we spend efforts to understand these relationships in nuclear magnetic resonance (NMR) parameters in a water solvent. This work takes advantage of the appropriate aug-cc-pVTZ-J basis set and the Minnesota family of DFT methods, which consider different portions of HFE contributions.

A DFT analysis of electronic, reactivity, and NLO responses of a reactive orange dye: the role of Hartree-Fock exchange corrections.

An experimental and theoretical study based on DFT/TD-DFT approximations is presented to understand the nature of electronic excitations, reactivity, and nonlinear optical (NLO) properties of reactive orange 16 dye (RO16), an azo chromophore widely used in textile and pharmacological industries. The results show that the solvent has a considerable influence on the electronic properties of the material. According to experimental results, the absorption spectrum is formed by four intense transitions, which have been identified as [Formula: see text] states using TD-DFT calculations.

Electron scattering processes in steroid molecules via NEGF-DFT: The opening of conduction channels by central oxygen.

We present a careful analysis of the electron transport in a variety of steroid derivatives attached among Au (111) electrodes. Our discussion is based on the non-equilibrium Green's function formalism coupled to the density functional theory, as well as appropriate parameters, such as the current-voltage behavior, differential conductance, rectification ratio, transmittance, the projected density of states, and the corresponding eigenchannels. The systems investigated present antagonistic features.

Study of the optical and magnetic properties of pyrimidine in water combining PCM and QM/MM methodologies.

The solvent effects on the low-lying absorption spectrum and on the (15)N chemical shielding of pyrimidine in water are calculated using the combined and sequential Monte Carlo simulation and quantum mechanical calculations. Special attention is devoted to the solute polarization. This is included by an iterative procedure previously developed where the solute is electrostatically equilibrated with the solvent.

NMR chemical shielding and spin-spin coupling constants of liquid NH3: a systematic investigation using the sequential QM/MM method.

The NMR spin coupling parameters, (1)J(N,H) and (2)J(H,H), and the chemical shielding, sigma((15)N), of liquid ammonia are studied from a combined and sequential QM/MM methodology. Monte Carlo simulations are performed to generate statistically uncorrelated configurations that are submitted to density functional theory calculations. Two different Lennard-Jones potentials are used in the liquid simulations.