| 1. |
- Bickelhaupt, F Matthias, et al.
(author)
-
Role of s-p orbital mixing in the bonding and properties of second-period diatomic molecules.
- 2008
-
In: Journal of Physical Chemistry A. - : American Chemical Society (ACS). - 1089-5639 .- 1520-5215. ; 112:11, s. 2437-46
-
Journal article (peer-reviewed)abstract
- Qualitative molecular orbital theory is widely used as a conceptual tool to understand chemical bonding. Symmetry-allowed orbital mixing between atomic or fragment orbitals of different energies can greatly complicate such qualitative interpretations of chemical bonding. We use high-level Amsterdam Density Functional calculations to examine the issue of whether orbital mixing for some familiar second-row homonuclear and heteronuclear diatomic molecules results in net bonding or antibonding character for a given molecular orbital. Our results support the use of slopes of molecular orbital energy versus bond distance plots (designated radial orbital-energy slope: ROS) as the most useful criterion for making this determination. Calculated atomic charges and frontier orbital properties of these molecules allow their acid-base chemistry, including their reactivities as ligands in coordination chemistry, to be better understood within the context of the Klopman interpretation of hard and soft acid-base theory. Such an approach can be extended to any molecular species.
|
|
| 2. |
- Goesten, Maarten, et al.
(author)
-
Cesium's off-the-map valence orbital
- 2017
-
In: Angewandte Chemie. - : Wiley. - 1521-3773 .- 1433-7851 .- 0044-8249 .- 1521-3757.
-
Journal article (peer-reviewed)abstract
- The Td-symmetric [CsO4]+ ion, featuring Cs in an oxidation state of 9, is computed to be a minimum. Cs uses outer core 5s and 5p orbitals to bind the oxygens. The valence Cs 6s orbital lies too high to be involved in bonding, and contributes to Rydberg levels only. From a Molecular Orbital perspective, the bonding scheme reminds of XeO4: an octet of electrons to bind electronegative ligands, and no low-lying acceptor orbitals on the central atom. In this sense, Cs+ resembles hypervalent Xe.
|
|
| 3. |
- Jimenez-Halla, J. Oscar C., et al.
(author)
-
Organomagnesium clusters : Structure, stability, and bonding in archetypal models
- 2011
-
In: Journal of Organometallic Chemistry. - : Elsevier BV. - 0022-328X .- 1872-8561. ; 696:25, s. 4104-4111
-
Journal article (peer-reviewed)abstract
- We have studied the molecular structure and the nature of the chemical bond in the monomers and tetramers of the Grignard reagent CH(3)MgCl as well as MgX(2) (X = H, Cl, and CH(3)) at the BP86/TZ2P level of theory. For the tetramers, we discuss the stability of three possible molecular structures of C(2h), D(2h), and T(d) symmetry. The most stable structure for (MgCl(2))(4) is D(2h), the one for (MgH(2))(4) is C(2h), and that of (CH(3)MgCl)(4) is T(d). The latter is 38 kcal/mol more stable with chlorines in bridge positions and methyl groups coordinated to a Mg vertex than vice versa. We find through a quantitative energy decomposition analysis (EDA) that the tetramerization energy is predominantly composed of electrostatic attraction Delta V(elstat) (60% of all bonding terms Delta V(elstat) + Delta E(oi)) although the orbital interaction Delta E(oi) also provides an important contribution (40%).
|
|
