Jean M. F. Custodio

Synthesis, characterization, and third-order nonlinear optical properties of a new neolignane analogue

Recently, a wide number of pharmacological activities, such as anti-leishmanial, antioxidant and antitumor, have been discovered for neolignane analogues. To provide a view of the non-linear optical behavior of the third order of the crystal 2-(4-nitrophenoxy)-1-phenylethanone (NPH-PE) in the static and dynamic cases, we calculated its linear polarizability (α) and second hyperpolarizability (γ). We used a new supermolecule approach combined with an iterative electrostatic system whose atoms of the neighboring molecules are represented by point charges. A comprehensive investigation of NPH-PE is reported by single crystal X-ray diffraction and FT-Raman and NMR spectroscopy. In addition, a combination of density functional theory (DFT) with the CAM-B3LYP functional and the 6-311+G(d) basis set was used to calculate the molecular structure optimization, the vibrational frequencies, and the intensity of the vibrational bands. Concerning the values of the third-order optical nonlinearity, the second hyperpolarizability of the embedded molecule showed an increase of 125 058% in comparison with the corresponding result in the static case.

The Influence of Methoxy and Ethoxy Groups on Supramolecular Arrangement of Two Methoxy-chalcones

The structures of two methoxylated chalcones, namely (E)-1-(4-methoxyphenyl)3-(3,4,5-trimethoxyphenyl)prop-2-en-1-one and (E)-3-(4-ethoxyphenyl)-1-(4-methoxyphenyl) prop-2-en-1-one, reveal the effect of the inclusion of the methoxyl and ethoxyl substituents of the conformation on methoxy-chalcone. Structural comparative study between two chalcones was done in this work and some effects on geometric parameters, such as planarity and dihedral angles, were described. In addition, intermolecular interactions responsible for crystalline packaging were investigated by Hirshfeld surfaces and the values of those interactions were analysed by comparing experimental and theoretical models. The molecular stability was expressed in terms of softness and hardness, both obtained from frontier molecular orbitals. Finally, there is a good agreement between calculated and experimental infrared spectrum, which allowed the assignment of the normal vibrational modes.

The solid state structure and environmental polarization effect of a novel asymmetric azine

A broad analysis of a novel azine is reported using single crystal X-ray diffraction and characterization methods (IR, NMR and MS). Additional studies were conducted using density functional theory with the CAM-B3LYP functional and the 6-311+G(d) basis set, with the intention of calculating molecular structure optimization, vibrational frequencies, and the intensity of the vibrational bands. These results were seen to be in close agreement with those reported in the literature. Besides that, we determined the linear polarization (α) and the second hyperpolarizability (γ) of this new azine to understand its linear and nonlinear optical behaviour in both static and dynamic cases. A new supermolecule approach is employed, combined with an interactive electrostatic system in which the atoms of the neighbouring molecules are considered as point charges. The ab initio computational results of (hyper) polarizabilities derived from an iterative process confirm this crystal as a good candidate for photonic devices, such as optical switches, modulators, pyrazoline derivatives, and optical power applications. Besides that, we also calculated the effect of the solvent on the nonlinear optical properties of the title compound.

Hirshfeld Surfaces and Nonlinear Optics on Two Conformers of a Heterocyclic Chalcone

Heterocyclic chalcones have been prominent in the scientific community due to various biological activities reported for these compounds. The structural knowledge of heterocyclic chalcones can help in the understanding of their mechanism of action. The Hirshfeld surfaces were used to study the supramolecular arrangement of two conformers present into asymmetric unit of the heterocyclic chalcone (2E)-3-(4-methylphenyl)-1-(pyridin-3-yl)-prop-2-en-1-one on crystalline state. In addition, the linear polarizability (α), the first hyperpolarizability (β||z), and the second hyperpolarizability (γ) of the conformers were calculated to get a better insight on the linear and nonlinear optical behaviors of these structures in presence of solvent medium, as well as their band-gap energies. The Hirshfeld surfaces confirmed the presence of C−H···N, C−H···O and C−H···C interactions in packaging stabilization. Finally, the 2D fingeprint plot was used to the quantification of contacts and indicated that there are both π···π and C−H···π interactions present in the compound.

A novel dihydrocoumarin under experimental and theoretical characterization

Coumarins are natural and synthetic active ingredients widely applied in diverse types of medicinal treatments, such as cancer, inflammation, infection, and enzyme inhibition (monoamine oxidase B). Dihydrocoumarin compounds are of great interest in organic chemistry due to their structural versatilities and, as part of our investigations concerning the structural characterization of small molecules, this work focuses on crystal structure and spectroscopic characterization of the synthesized and crystallized compound 4-(4-methoxyphenyl)-3,4-dihydro-chromen-2-one (C16H14O3). Additionally, a theoretical calculation was performed using density functional theory to analyze the sites where nucleophilic or electrophilic attack took place and to examine the molecular electrostatic potential surface. Throughout all of these calculations, both density functional theory and Car–Parrinello molecular dynamics were performed by fully optimized geometry. The spectroscopic analysis indicated the presence of aromatic carbons and hydrogen atoms, and also the carbonyl and methoxy groups that were confirmed by the crystallographic structure. The C16H14O3 compound has a non-classical intermolecular interaction of type C–H⋅⋅⋅O that drives the molecular arrangement and the crystal packing. Moreover, the main absorbent groups were characterized throughout calculated harmonic vibrational frequencies. Also, natural bond orbital analysis successfully locates the molecular orbital with π-bonding symmetry and the molecular orbital with π* antibonding symmetry. Finally, the gap between highest occupied and lowest unoccupied molecular orbitals implies in a high kinetic stability and low chemical reactivity of title molecule.

Structural insights into a novel anticancer sulfonamide chalcone

Natural products have stood out due to their wide range of biological activities. Among the various naturally occurring classes, we can highlight chalcones, sulfonamides and hybrid compounds formed by both. Although many pharmacological activities of these classes of compounds are known, new ones have arisen lately and require detailed structural and biological analyses. Herein, we report the synthesis and structural elucidation of a novel sulfonamide chalcone 2,5-dichloro-N-{3-[(2E)-3-(4-nitrophenyl)prop-2-enoyl]phenyl}benzenesulfonamide (BSC) by Single Crystal X-ray Diffraction and spectroscopy analysis (Infrared, NMR and Mass Spectroscopy). Topology was determined through Hirshfeld surface analysis and the electrostatic potential map, while the energy of frontier molecular orbitals was used to evaluate the stability of BSC. Additionally, the cytotoxicity of the title compound was evaluated through the MTT colorimetric method. We show that the BSC compound has a planar conformation in its chalcone portion, which is further corroborated by the low angle between the aromatic rings (5.23°). In addition, intermolecular interactions of type C–H⋯O and N–H⋯O make up a dimeric supramolecular arrangement. An inverse virtual screening approach allowed identifying potential biological applications for BSC, which indicated that BSC might interact with the binding sites of RARα and RARβ. Consequently, BSC was experimentally evaluated against three cancer cell lines, and was shown to hold potent anticancer activity. In addition, a cytotoxic effect was observed for all strains, which was more pronounced for HCT-116, a colon cancer cell line.

Conformation analysis of a novel fluorinated chalcone

Chalcones are an important class of natural compounds that exhibit numerous biological activities. In this paper, we report the synthesis and characterization of new fluorinated chalcone (FCH). The molecular geometry was determined by means of single crystal X-ray diffraction, and density functional theory (DFT) at B3LYP, M06-2X functionals and MP2 method, with the 6-311++G(d,p) basis set, was applied to optimize the ground state geometry and to study the molecular conformational stability. The molecular electrostatic potential (MEP) was also investigated at the same level of theory in order to identify and quantify the possible reactive sites. The FCH crystallizes in the centrossymmetric space group P1¯

The effect of propanone molecule on supramolecular arrangement of solvatomorphs of a novel anticancer sulfonamide chalcone

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