Dipole Moment
Mostrando 1-12 de 98 artigos, teses e dissertações.
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1. COMPARAÇÃO ENTRE MÉTODOS PARA DETERMINAÇÃO DE CARGAS ATÔMICAS EM SISTEMAS MOLECULARES: A MOLÉCULA N-{N-(PTERINA-7-IL)CARBONILGLICIL}-L-TIROSINA (NNPT)
Selecting a method to compute partial atomic charges is not trivial because different methods usually provide different charge values and there is no consensus on the most useful approach. In this work, Mulliken, MBS, Chelp, Chelpg, MK, Hirshfeld, NPA, DMA and AIM methods were selected to compute atomic charges and electric dipole moment vector of N-{N-(Pter
Quím. Nova. Publicado em: 2021-02
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2. An Alternative Description for the Electronegativity Difference in Binary Ionic Solids
We are introducing an alternative analytical expression to the electronegativity difference (∆χ) as a function of the charge ge, g is the charge factor, the fraction of the electronic charge devoted to the bond and e the elementary charge, the packing factor (p) and the effective atomic number (Zeff) of binary ionic solids, by using the very basic Coulomb
J. Braz. Chem. Soc.. Publicado em: 2021-02
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3. CARCINOGENICIDADE DE HIDROCARBONETOS POLICÍCLICOS AROMÁTICOS
The assessment of the carcinogenic potential of polycyclic aromatic hydrocarbons (PAH) is obtained by a principal component analysis (PCA) and quantitative structure-activity relationship (QSAR) using hydrophobic (LogP), stereo and electronic parameters (electron affinity, dipole moment and HOMO-LUMO gap) calculated from the AM1 method. The PAH-DNA interacti
Quím. Nova. Publicado em: 2016-08
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4. Review of Experimental GAPT and Infrared Atomic Charges in Molecules
This review contains experimental values of polar tensors and generalized atomic polar tensor (GAPT) charges determined since the publication of the polar tensor formulism for infrared intensity interpretation in 1961. GAPT charges, also called mean dipole moment derivatives, for 167 atoms of 67 molecules are discussed and compared with infrared charges also
J. Braz. Chem. Soc.. Publicado em: 2016-06
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5. NANOPARTICLES OF TUNGSTEN AS LOW-COST MONOMETALLIC CATALYST FOR SELECTIVE HYDROGENATION OF 3-HEXYNE
Low-cost tungsten monometallic catalysts containing variable amounts of metal (4.5, 7.1 and 8.5%W) were prepared by impregnating alumina with ammonium metatungstate as an inexpensive precursor. The catalysts were characterized using ICP, XPS, XRD, TPR and hydrogen chemisorption. These techniques revealed mainly WO3-Al2O3 (W6+) species on the surface. The eff
Quím. Nova. Publicado em: 2016-01
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6. UNA PROPUESTA PARA ENSEÑAR EL EFECTO DE LA FORMA DE LAS MOLÉCULAS EN LA REACTIVIDAD QUÍMICA
We address the concept of steric effect in the pursuit of establishing quantitative correlations between reactivity of molecules and their molecular shape. To this end, a set of series of SN2 reactions were modeled to compute the energy barrier height and the molecular volume, atomic charges and dipole moment of molecules. We introduced the Kappa index to ch
Quím. Nova. Publicado em: 2015-03
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7. Cromatografia gasosa-espectrometria de massas e derivatização assistida por micro-ondas na identificação de isômeros de glicose: uma prática para o ensino avançado em análise e caracterização de compostos orgânicos
This work reports a practical case based on the use of microwave-assisted derivatization and GC-MS for the analysis of glucose. Using two different methods for derivatization, one reference compound and the calculated dipole moment, all the isomers of glucose were identified. Identification was corroborated for the assignment of structures using the mass spe
Quím. Nova. Publicado em: 2014
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8. Carcinogenicidade do carbendazim e seus metabólitos
The carcinogenic potential of carbendazim and its metabolites was analyzed using statistical treatment of electronic parameters obtained from DFT/ 6-311++G(d,p) and AM1 calculations. The carcinogen-DNA interaction is described in the framework of the theory of unsynchronized resonance of covalent bond as a process of electron transfer involving the HOMO and
Quím. Nova. Publicado em: 2014
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9. Estudo teórico da estrutura eletrônica e da dinâmica induzida por lasers da molécula de HCl
Potential energy and dipole moment curves for the HCl molecule were computed. Calculations were performed at different levels of theory (DFT, MRCI). Spectroscopic properties are reported and compared with experimental data, for validating the theoretical approaches. Interaction of infrared radiation with HCl is simulated using the wave packet formalism. The
Quím. Nova. Publicado em: 2013
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10. Planejamento, síntese e avaliação da atividade anti-T. cruzi de derivados furfurilidênicos com estruturas azometínica e oxadiazolínica / Design, synthesis, identification and anti-Trypanosoma cruzi activity evaluation of furfurylidene azomethine and oxadiazole derivatives
The search for alternative therapies for the treatment of Chagas disease presents great importance, since there are only two currently available drugs, nifurtimox and benznidazole. Both have considerable adverse effects and, in Brazil, is used only benznidazole. Nitro-heterocyclic compounds with activity against Trypanosoma cruzi, the causative agent of Chag
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 27/06/2012
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11. Design de novos derivados da ftalocianina de zinco para emprego em óptica não-linear
O presente trabalho tem como objetivo a proposição, por Engenharia Molecular, de derivados da Ftalocianina de Zinco com características desejáveis para aplicação em fotônica. Para caracterizar esses compostos, foi empregado um estudo teórico, incluindo estrutura eletrônica, geometria, energia dos estados, transições eletrônicas e algumas propried
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 15/02/2012
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12. Estudo químico-quântico de corantes catiônico e aniônicos para aplicação em terapia fotodinâmica / Quantum-chemical study of cationic and anionic dyes applied in photodynamic therapy / Estudo químico-quântico de corantes catiônico e aniônicos para aplicação em terapia fotodinâmica / Quantum-chemical study of cationic and anionic dyes applied in photodynamic therapy
The present work studies the dyes Methylene Blue, Toluidine Blue, Eosin Y, Erytrosin B, Fluorescein and Rose Bengal using quantum-chemical calculations, aiming to propose an appropriate Density Functional Theory-based methodology and to understand the mechanisms of action of those dyes in photodynamic therapy. Structures in singlet and triplet states were op
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 06/04/2011