Results 161 to 170 of about 4,402 (189)

An observable-based interpretation of electronic wavefunctions: application to “hypervalent” molecules

Journal of Molecular Structure: THEOCHEM, 1992
Abstract The quantum-mechanical definition of observables is extended to all properties that can be derived from experimentally measurable quantities with the help of universal operators. Even such an extended definition, however, does not cover several commonly used concepts such as atomic orbitais in molecules or Mulliken atomic charges. Principles
Jerzy Cioslowski, Péter R. Surján
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Effectively hypervalent molecules. 2. Lithium carbide (CLi5), lithium carbide (CLi6), and the related effectively hypervalent first row molecules, CLi5-nHn and CLi6-nHn

Journal of the American Chemical Society, 1983
Calculs ab initio indiquant des molecules tres stables: energies totales, energies de dissociation. Distributions de charge electronique et conformations: ces molecules ne seraient pas hypervalentes au sens strict, les electrons excedentaires etant mis en jeu dans des liaisons Li ...
Timothy Clark, Ernst Ulrich Wuerthwein, John A. Pople, Elmar Kaufmann, Paul von Ragué Schleyer   +4 more
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ChemInform Abstract: THE HYPERVALENT MOLECULES SULFURANE (SH4) AND PERSULFURANE (SH6)

Chemischer Informationsdienst, 1975
GRETCHEN M. SCHWENZER, HENRY F. III SCHAEFER   +1 more
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The role of O(¹D) in the oxidation mechanism of ethylene by iodosobenzene and other hypervalent molecules

Physical Chemistry Chemical Physics, 2017
Terminal iodine–oxygen bonds are described as PhI → O(1D) dative bonds explaining the oxidation properties of iodosobenzene or other “hypervalent” species.
Shahriar N. Khan, Evangelos Miliordos
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Thermodynamic stability and optimized structures of hypervalent molecules M2CN (M = Li, Na, K)

Thermochimica Acta, 1997
Abstract The hypervalent M2CN (M = Li, Na, K) molecules have been detected in the vapor at elevated temperatures over mixtures of alkali metals and sodium cyanide by means of Knudsen-effusion mass spectrometry. The experimentally obtained ionization energies were IP (Li2CN+) = 5.4 ± 0.2 eV, IP(Na2CN+) = 4.9 ± 0.2 eV and IP (K2CN+) = 4.0 ± 0.2 eV ...
Keiichi Yokoyama, Chao Wu, Paul von Ragué Schleyer, Hiroshi Kudo, Masashi Hashimoto   +4 more
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Semi-empirical atomic charges and dipole moments in hypervalent sulfonamide molecules: descriptors in QSAR studies

Journal of Molecular Structure: THEOCHEM, 1998
The Mulliken and ESP-based atomic charges and dipole moments have been calculated for a group of substituted methanesulfonamides by several ab initio and semi-empirical methods, in order to find the most reliable semi-empirical method of calculating these quantities in hypervalent molecules.
Claudiu T. Supuran, Brian W. Clare, Brian W. Clare   +2 more
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Intermolecular interactions between hypervalent molecules: Ph2IX and XF3 (X=Cl, Br, I) dimers

New Journal of Chemistry, 1998
The intermolecular bonding in dimers of the T-shaped hypervalent title compounds is analyzed using a combination of density functional calculations and qualitative arguments. Fragment molecular orbital interaction diagrams lead us to the conclusion that the bonding in these species can be understood using the language of donor-acceptor interactions ...
Ruslan M. Minyaev, Roald Hoffmann, Norman Goldberg, Gregory A. Landrum   +3 more
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A study of the target gas dependence on the collisional ionization mass spectra of some metastable and hypervalent molecules

International Journal of Mass Spectrometry and Ion Processes, 1985
Collisional ionization mass spectra of a fast beam of neutral molecules with ionization potentials in the range 4–5 eV have been obtained with a series of target gases, NO2, O2, N2 and He. Neutral beams were generated in a near resonant electron transfer process X+ +K(g) → X* + K+ where X+ is He2+, H3+, ND4+ or N2D7+.
Richard F. Porter, Gregory I. Gellene
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Bonding in ClF_n (n = 1−7) Molecules: Further Insight into the Electronic Structure of Hypervalent Molecules and Recoupled Pair Bonds

The Journal of Physical Chemistry A, 2009
As a result of new studies into the nature of hypervalent molecules, we identified a new type of bond called a recoupled pair bond. Hypervalency or hypercoordination was shown to arise by decoupling a pair of valence electrons, each of which becomes available to participate in a new bond.
David E. Woon, Lina Chen, Thorn H. Dunning   +2 more
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Chemical bonding in hypervalent molecules. The dominance of ionic bonding and negative hyperconjugation over d-orbital participation

Journal of the American Chemical Society, 1990
Does sulfur form six covalent bonds in CH{sub 3}SO{sub 2}Cl, F{sub 3}S{triple bond}N or carbon or phosphorus five bonds in F{sub 3}C=O{sup {minus}}, F{sub 3}P=O After a brief history of the viewpoints on hypervalent bonding and a comparison of analysis methods (with CH{sub 3}SO{sub 2}Cl as example), natural population and natural bond orbital analysis ...
P. Von Rague Schleyer, Alan E. Reed
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