Search results for "Extended Hückel method"

showing 2 items of 2 documents

Theoretical EHT study of oxidative coupling of methane on pure MgO and MgO doped with Li and Na

1991

Abstract On the basis of Extended Huckel Theory, empirical studies on the oxidative coupling of methane with MgO pure and MgO doped with Li and Na are presented. The results obtained from the two-dimensional energy surfaces calculated for the interaction between linear clusters of these oxides and the methane molecule show a qualitative agreement with the experimental behaviour reported for these catalysts. The calculated activation energy barriers are in accord with the relative activities of these oxides (Li/MgO > Na/ MgO > MgO) and are of the same order of magnitude as the experimentally determined activation energies.

Inorganic chemistryDopingGeneral Engineeringchemistry.chemical_elementActivation energyHückel methodAlkali metalExtended Hückel methodMethaneCondensed Matter::Materials Sciencechemistry.chemical_compoundchemistryCondensed Matter::SuperconductivityPhysics::Atomic and Molecular ClustersPhysical chemistryOxidative coupling of methaneLithiumPhysics::Chemical PhysicsJournal of Molecular Catalysis
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Molecular materials with conducting and magnetic properties based on ET and [ M(tdas)2]x-dithiolenes

2004

Two hybrid molecular materials showing a combination of magnetic and conducting properties, the charge-transfer (ET) 2 [Fe(tdas) 2 ] (1) and (ET)Ni(tdas) 2 (2), (ET=bis(ethylenedithio) tetrathiafulvalene; M=Fe, Ni; tdas=l,2,5-thiadiazole-3,4-dithiolate) salts, are characterized by vibrational (IR and Raman) and UV-VIS-NIR spectroscopies. These studies have proved to be effective and diagnostic tools in identifying the oxidation state (partial or integer) and the packing pattern (dimers or segregated stacks) of the ET donor only, since no v(C=C) group vibration sensitive to the charge of M(tdas) 2 complexes has been observed. This is ascribed to the extensive electron-delocalization inside t…

StereochemistryChemistryIntermolecular forceGeneral Physics and AstronomyRing (chemistry)Extended Hückel methodCrystallographysymbols.namesakechemistry.chemical_compoundElectrical resistivity and conductivityOxidation stateMolecular vibrationsymbolsRaman spectroscopyTetrathiafulvaleneJournal de Physique IV (Proceedings)
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