Atoms
Mostrando 1-12 de 1543 artigos, teses e dissertações.
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1. RING CURRENT IN ANTHRACENE AND PHENANTHRENE: CORRECTION TO HÜCKEL PARAMETERS
Excessive degeneracy in the ground state of the π-electron energy levels of anthracene was removed using the Hückel method by correcting the Coulomb integral of the four central carbon atoms. A further correction to the resonance integral was proposed based on the ring-current model, which describes the π-ring current flow along the molecule’s perimeter
Química Nova. Publicado em: 2022
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2. A New Synthetic Route and Comprehensive Topological Study of a Benzimidazole Derivative
Benzimidazole and its derivatives are molecules that have diverse biological properties, therefore we synthesized and studied a new benzimidazole to understand their physical/chemical properties. The compound was obtained through a new synthetic route, using graphite oxide, in the absence of solvent, with crystalline packaging supported by C-H…N and C-H…
Journal of the Brazilian Chemical Society. Publicado em: 2022
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3. Silver complexes for tuberculosis treatment: a short review
This paper is a brief review of silver complexes that have been identified as antibacterial drugs with promising use for the treatment of tuberculosis (TB). This treatment aims to cure and discontinue the transmission of the disease. The excessive and inappropriate use of drugs has jeopardized the effectiveness of antibiotics for the TB treatment, bringing b
Química Nova. Publicado em: 2022
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4. Synthesis and Molecular Modeling Study of Two Bromo-Dimethoxybenzaldehydes
This work describes the synthesis, molecular structure, and packaging of the compounds 6-bromo-2,3-dimethoxybenzaldehyde (6-BRB) and 5-bromo-2,3-dimethoxybenzaldehyde (5 BRB). Characterization in the solid-state was carried out by X-ray diffraction, and the analysis of the interactions was described by the Hirshfeld surface, which helps in understanding the
Journal of the Brazilian Chemical Society. Publicado em: 2022
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5. Through-Bond and Through-Space Interactions in [2,2]Cyclophanes
The interpretation of the distortions of the electron distribution in [2,2]cyclophanes (22-CPs) is controversial. Some studies indicate that there is an accumulation of electron density (ρ) outside the cavity of 22-CPs. The nature of through-space (ts) interaction is still under debate. The relative importance of ts and through-bond (tb) is an open question
J. Braz. Chem. Soc.. Publicado em: 2021-07
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6. First-Principles Calculations of a New Semi-Conductive Carbon Allotrope Named ABF-Carbon
Carbon is an extremely versatile element and can generate a plethora of structures with distinct properties. Proposing new possible metastable allotropic structures for carbon has been the subject of increasing interest over the past few years. In this contribution, we present a new carbon allotrope, named ABF-Carbon, based on the connection of spiropentadie
J. Braz. Chem. Soc.. Publicado em: 2021-04
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7. THEORETICAL UNDERSTANDING OF MORPHOLOGICAL DISTRIBUTION OF HYDROGEN IN AMORPHOUS CALCIUM SILICATE HYDRATE
Determining the morphological distribution of hydrogen atoms in calcium silicate hydrate phase (C-S-H) is of great concern but challenging. In this work, based on the stoichiometric composition of (CaO)1.7(SiO2)(H2O)1.8, a series of amorphous Ca1.7•Si•(O)3.7-x•(OH)2x•(H2O)1.8-x models are constructed using Monte Carlo method, where x represents the m
Quím. Nova. Publicado em: 20/07/2020
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8. A UNIFIED FORMULA FOR HYDROCARBONS WITH APPLICATIONS TO FUNCTIONAL GROUPS
Was supposed a numerical relationship between atoms of Hydrogen and Carbon in a hydrocarbon, assumption valid for all types of chains. In the proposed equation, variables such as number and types of carbon bonds are present, as well as the possible cycles. It was shown that the equation reduces to the known “general formulas” when applied to the type of
Quím. Nova. Publicado em: 20/07/2020
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9. COVID-19: Um Novo Desafio para a Cardiopatia na Gravidez
This work presents the results obtained for the gas chromatography-mass spectrometry (GC-MS) monitoring of the liquid-phase hydrodeoxygenation (HDO) reaction of furfural (FFR) to 2-methylfuran (MF) over a bifunctional Ru/RuOx/C catalyst in the presence of a direct source of H2. Hydrogenation and hydrogenolysis reactions of FFR and of the intermediate furfury
Arq. Bras. Cardiol.. Publicado em: 2020-07
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10. Furfural Hydrodeoxygenation over a Ruthenium-Based Bifunctional Catalyst in the Presence of a Direct Source of H2
This work presents the results obtained for the gas chromatography-mass spectrometry (GC-MS) monitoring of the liquid-phase hydrodeoxygenation (HDO) reaction of furfural (FFR) to 2-methylfuran (MF) over a bifunctional Ru/RuOx/C catalyst in the presence of a direct source of H2. Hydrogenation and hydrogenolysis reactions of FFR and of the intermediate furfury
J. Braz. Chem. Soc.. Publicado em: 2020-07
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11. Pesquisas em políticas de comunicação em contextos de crise
By way of Density Functional Theory (DFT)-based computational methods with commercially available software, the computational work of which about the molecular properties, the vibrational modes and vibrational frequencies of finasteride were accomplished for the first time. In order to gain a deeper and more thorough understanding of the molecular structure
Intercom, Rev. Bras. Ciênc. Comun.. Publicado em: 2020-05
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12. VIBRATIONAL SPECTROSCOPIC INVESTIGATION AND MOLECULAR STRUCTURE OF A 5α-REDUCTASE INHIBITOR: FINASTERIDE
By way of Density Functional Theory (DFT)-based computational methods with commercially available software, the computational work of which about the molecular properties, the vibrational modes and vibrational frequencies of finasteride were accomplished for the first time. In order to gain a deeper and more thorough understanding of the molecular structure
Quím. Nova. Publicado em: 2020-05