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| 2. |
- Arteca, Gustavo A., et al.
(author)
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Constructing quantum mechanical models from diabatic schemes : external field modulation of effective energy barriers for bond breaking/formation processes
- 2014
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In: Journal of Mathematical Chemistry. - : Springer Science and Business Media LLC. - 0259-9791 .- 1572-8897. ; 52:9, s. 2395-2410
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Journal article (peer-reviewed)abstract
- We have recently proposed an approach where chemical transformations can be described as quantum processes involving the modulation of entangled states by an applied external field (Arteca and Tapia in Phys Rev A 84:012115, 2011). In practical implementations, we gain insight into these processes by using simple quantum-mechanical models derived from diabatic schemes. In this context, reactant, product, and, eventually, intermediate species, are assigned to diabatic basis functions, and then entangled by an external field into a quantum state from which all observable properties of the chemical reaction should emerge. Here, we extend our previous model for bond breaking/formation in diatomic molecules (Arteca et al. in J Math Chem 50:949, 2012). We consider the entire manifold of semiclassical models defined by only two diabatic basis functions: a harmonic well for the "molecular" bound state, and an exponential potential energy function for the asymptotically separated fragments (the "product" channel). Using a two-parameter space to describe all models, we determine how the topology of the total energy function is affected by the shape of the applied field. We show that strong and weak local couplings with the external field modify substantially the occurrence of energy barriers, in contrast to using the uniform (i.e., space-invariant) coupling employed in previous works.
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| 3. |
- Paulino, M., et al.
(author)
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Studies of trypanocidal (inhibitory) power of naphthoquinones: : evaluation of quantum chemical molecular descriptors for structure-activity relationships
- 2008
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In: European Journal of Medicinal Chemistry. - : Elsevier BV. - 0223-5234. ; 43:10, s. 2238-2246
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Journal article (peer-reviewed)abstract
- Electronic, lipophilic and steric descriptors included in QSAR-2D and -3D are analyzed for a set of ortho- and para-naphthoquinones that have proved to be powerful oxidative agents with potent trypanocidal activities specially against Leptomonas seymouri and Trypanosoma cruzi. Electronic properties are calculated by means of semiempirical (PM3), ab initio (HF/3-21G) and density functional theory (B3LYP/6-31 + G*) methodologies. Three different electronic states, neutral quinones, hydroquinones and semiquinones, are studied to investigate if any one of them are statistically related with the biological activities. The best correlations were obtained at the B3LYP level of theory because it includes electronic correlation. The QSAR-2D indicates that the best trypanocidal growth inhibitors are molecules in the semiquinone electronic state, with the following properties: (a) high negative value of EHOMO, (b) high negative charge in the oxygen atoms of the carbonyl groups, (c) high positive charge in the carbon atom of one of carbonyl moieties and (d) high electronegativity (χ). In a complementary way, the QSAR-3D indicates that the electrostatic field correlates with trypanocidal activity and the presence of bulk moieties would increase activity. The idea of comparing the three electronic states may prove to be of most importance in the general strategy to the design of new trypanocidal drugs. In fact, the experimental results showed that semiquinone is the one really statistically relevant indicating a clear connection between biochemical and theoretical aspects. Finally, we demonstrated that to be a good anti-trypanosomatid compound, the molecule must be a good electron acceptor to reach easily the essential semiquinone state. We expect that the present results motivate new experimental as well as theoretical investigations that confirm our findings.
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| 4. |
- Tapia-Olivares, Orlando
(author)
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Quantum-matter photonic framework perspective of chemical processes : Entanglement shifts in HCN/CNH isomerization
- 2015
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In: International Journal of Quantum Chemistry. - : Wiley. - 0020-7608 .- 1097-461X. ; 115:20, s. 1490-1500
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Journal article (peer-reviewed)abstract
- A complete electro-nuclear (EN) basis set and quantum electrodynamics bases in photon number scheme combines to form photonic bases sets. The EN q-states can hence be modulated by appropriate external electromagnetic sources. Quantum determinants for HCN/CNH isomerization within photonic bases are elaborated that rationalize quantum state changes as if it were an apparent unimolecular process. Topologic label of base states permit linking with those obtained with semiclassic schemes. A comparison of results leads to conclude that both schemes can turn out to be complementary. The q-scheme yielding more detailed information that the semiclassic one as expected.
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| 5. |
- Aad, G., et al.
(author)
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- 2016
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In: Journal of High Energy Physics. - : Springer. - 1029-8479 .- 1126-6708. ; :1
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Journal article (peer-reviewed)
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| 6. |
- Aad, G., et al.
(author)
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- 2015
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In: Physical Review D. Particles and fields. - : American Physical Society. - 0556-2821 .- 1089-4918. ; 92:9
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Journal article (peer-reviewed)
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| 7. |
- Aad, G., et al.
(author)
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- 2015
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In: Physical Review D. Particles and fields. - : American Physics Society. - 0556-2821 .- 1089-4918. ; 92:11
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Journal article (peer-reviewed)
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| 8. |
- Aad, G., et al.
(author)
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- 2015
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In: Journal of High Energy Physics. - : Springer. - 1029-8479 .- 1126-6708. ; :12
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Journal article (peer-reviewed)
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| 9. |
- Aad, G., et al.
(author)
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- 2016
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In: Physical Review D. Particles and fields. - : American Physical Society. - 0556-2821 .- 1089-4918. ; 93:1
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Journal article (peer-reviewed)
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