Results 141 to 150 of about 4,402 (189)

Predicting the Stability of Hypervalent Molecules

Journal of Chemical Education, 2007
In this exercise, students use concepts in thermochemistry such as bond energy, ionization potentials, and electron affinities to predict the relative stability of two hypervalent molecules (PF5 and PH5) relative to their respective non-hypervalent counterparts.
Jeremy Kua, Debbie Finocchio, Tracy A. Mitchell   +2 more
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Hypervalent Silicon and Phosphorus Atoms in Single Molecules: Synthesis and Properties of Phosphoranylalkoxysilicates and a Phosphoranyloxysilicate

Chemistry Letters, 2007
Abstract The first hypervalent compounds containing both a pentacoordinated silicon atom and a pentacoordinated phosphorus atom were synthesized by the cooperative three-component reaction of a phosphoranide, a silane, and THF accompanying the ring opening of THF, or by the nucleophilic addition of phosphoranylalkoxides to a silane ...
Hideaki Miyake, Takayuki Kawashima, Naokazu Kano   +2 more
  +5 more sources

Remarkable Enhancement of Photoallylation of Aromatic Carbonyl Compounds with a Hypervalent Allylsilicon Reagent by Donor Molecules.

ChemInform, 2007
AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Yutaka Nishigaichi, Akio Takuwa, Akira Suzuki   +2 more
  +6 more sources

Chemical Bonding in Hypervalent Molecules:  Is the Octet Rule Relevant?

Inorganic Chemistry, 2002
The bonding in a large number of hypervalent molecules of P, As, S, Se, Te, Cl, and Br with the ligands F, Cl, O, CH(3), and CH(2) has been studied using the topological analysis of the electron localization function ELF. This function partitions the electron density of a molecule into core and valence basins and further classifies valence basins ...
Bernard Silvi, Stéphane Noury, Ronald J. Gillespie   +2 more
openaire   +4 more sources

Effectively hypervalent molecules. 3. Hypermetalation involving sodium: ONa3, ONa4, HONa2, and HONa3

Journal of the American Chemical Society, 1984
Calculs MO ab initio montrant que les molecules ONa 3 et ONa 4 sont stables avec des liaisons Na-O un peu plus longues que dans Na 2 O et NaOH et que les 9eme et 10eme electrons de ces molecules hypervalentes interviennent dans la liaison metal-metal plutot que dans la liaison metal ...
Ernst Ulrich Wuerthwein, Paul von Ragué Schleyer   +1 more
openaire   +3 more sources

On the important role played by polarization functions in calculations involving hypervalent molecules

Chemical Physics Letters, 2000
Abstract It is shown that special care must be taken to choose a basis set with an appropriate number of polarization functions when studying processes involving several hypervalent molecules, each with some particular atom exhibiting different Lewis structures.
J. Sordo
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Sulfuranes Lacking Benzoannelation. Sulfuranes and Other Hypervalent Molecules Studied by ¹⁷O-NMR

The Journal of Organic Chemistry, 1999
The rates of hydrolysis of benzoannelated vs nonbenzoannelated sulfuranes, viz. 5 vs 3 or 5 vs 4, were compared. Benzoannelation was found to provide very modest kinetic stabilization. Crystal structures of sulfuranes 3 and 4 were obtained and compared with each other, with a dibenzoannelated sulfurane, 17, and with a non-sulfurane analogue of 4.
Peter Livant, Thomas R. Webb, William B. Lott, Zwei-Chang Ho   +3 more
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Experimental and theoretical investigation of new hypervalent molecules LinF (n=2–4)

Chemical Physics Letters, 2007
Abstract Hypervalent molecules of Li 3 F and Li 4 F were detected experimentally for the first time. Ionization energies determined by the thermal ionization mass spectrometry were 3.8 ± 0.2 eV for Li 2 F, 4.0 ± 0.2 eV for Li 3 F and 3.9 ± 0.2 eV for Li 4 F.
Veličković, Suzana, Koteski, Vasil J., Belošević-Čavor, Jelena, Đorđević, Vesna R., Cvetićanin, Jelena M., Đustebek, Jasmina B., Veljković, Miomir V., Nešković, Olivera M.   +7 more
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Application of local-density functional theory to molecules containing a hypervalent bond

International Journal of Quantum Chemistry, 1991
The molecular and electronic structures of ADPO 1, a model thiapentalene 2, and [Xe2F3]+ have been calculated in the local-density functional (LDF) formalism with polarized double numerical basis sets. The molecules were calculated to have planar C2ν structures in agreement with experiment and in contrast to Hartree–Fock molecular-orbital calculations.
Anthony J. Arduengo, David A. Dixon
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Synthesis, structural characterization and ab initio calculation of dipyridyltetraazathiapentalene: a highly conjugative polycyclic molecule with hypervalent N–S–N bond

Journal of Molecular Structure, 2002
通讯作者地址: Zheng, LS (通讯作者), Xiamen Univ, Dept Chem, State Key Lab Phys Chem Solid Surfaces, Xiamen 361005, Peoples R China 地址: 1.
Rong-Bin Huang, Xin Lu, Nan-Feng Zheng, You-Si Zou, Shun-Liu Deng, Hui-Ping Zhong, Su-Yuan Xie, La-Sheng Long, Lan-Sun Zheng   +8 more
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