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Density functional theory study for the cycloaddition of 1,3-butadienes with dimethyl acetylenedicarboxylate. Polar stepwise vs concerted mechanisms
(2002)
The molecular mechanisms for the cycloaddition reactions of four low activated 1,3-butadiene systems (1,3-butadiene, (E)-1,3-pentadiene, (Z)-1,3-pentadiene, and 4-methyl-1,3-pentadiene) with dimethyl acetylenedicarboxylate ...
Highly stereoselective and catalyst-free synthesis of annulated tetrahydropyridines by intramolecular imino-Diels-Alder reaction under microwave irradiation in water
(Royal Society of Chemistry, 2016)
A microwave-assisted method for the synthesis of tetracyclic tetra-hydropyridines via an intramolecular imino-Diels-Alder reaction in water is reported. The reaction proceeds under catalyst-free conditions and shows excellent ...
Understanding the stereo- and regioselectivities of the polar Diels-Alder reactions between 2-acetyl-1,4-benzoquinone and methyl substituted 1,3-butadienes: a DFT study
(JOHN WILEY & SONS LTD, 2009-06)
The polar Diels-Alder (DA) reactions of 2-acetyl-1,4-benzoquinone (acBQ) with methyl substituted 1,3-butadienes have been studied using DFT methods at the B3LYP/6-31 G(d) level of theory. These reactions are characterized ...
The supramolecular behavior of the polycatenated double-layer coordination polymer [Cd2(isonicotinate)4(pab)(H2O)] n (pab = 1,4-di-4-pyridyl-2,3-diaza-1,3-butadiene)
(Elsevier B.V., 2010)
The reaction mixture of pab and isonicotinate ligands with cadmium(II) nitrate under hydrothermal conditions generates a novel three-dimensional catenate framework, namely [Cd2(isonicotinate)4(pab) (H2O)]n (1) (pab = ...
Relationship between singlet-triplet excitation energies and the Kohn-Sham orbitals obtained with potentials that exhibit a wrong asymptotic behavior
(ELSEVIER, 2006-02-15)
A linear relationship was found between the singlet-triplet excitation energy and the energy difference presented by the Kohn-Sham frontier molecular orbitals, independently of the used exchange-correlation functional and ...
Understanding the influence of Lewis acids in the regioselectivity of the Diels–Alder reactions of 2-methoxy-5-methyl-1,4-benzoquinone: A DFT study
(Elsevier B.V., 2009-03-03)
The mechanisms of the Diels–Alder (DA) reactions of 2-methoxy-5-methyl-1,4-benzoquinone 1 with 2-
methyl-1,3-butadiene 2, in the absence and in the presence of LA catalysts, have been studied using the
DFT method at the ...
Complex Dielectric Permittivity of Engineering and 3D-Printing Polymers at Q-Band
(Springer New York LLC, 2018)
We report experimental values of the complex dielectric permittivity of a wide variety of engineering polymers. Measurements were done using the filling waveguide method at Q-band (30–50 GHz), being representative of the ...
Electro-mechanical actuation performance of SEBS/PU blends
(Elsevier Ltd, 2019)
Dielectric elastomers have been regarded as truly artificial muscles for their electro-mechanical (EM) actuation performance. However, they require large driving voltages to present adequate actuation strains. The main ...
Understanding the influence of Lewis acids in the regioselectivity of the Diels-Alder reactions of 2-methoxy-5-methyl-1,4-benzoquinone: A DFT study
(2009)
The mechanisms of the Diels-Alder (DA) reactions of 2-methoxy-5-methyl-1,4-benzoquinone 1 with 2-methyl-1,3-butadiene 2, in the absence and in the presence of LA catalysts, have been studied using the DFT method at the ...
Contaminación atmosférica y efectos respiratorios en niños, en mujeres embarazadas y en adultos mayores
(Bogotá : Universidad de Ciencias Aplicadas y Ambientales, 2008, 2008-01)
Respiratory diseases asacute respiratory infection (ARI) and pulmonary chronic obstructive disease (PCOD) are a group of pathologies that affect the respiratory system, being a very common cause of morbidity and mortality ...