O-Hole interactions

Pohtzer, R, Murray, J. S., Clark, T. (2013) Halogen bonding and other o-hole interactions a perspective. Physical Chemistry Chemical Physics, 15(21), 11178-11189, Clark, T. (2013). o-Holes. Wiley Interdisciplinary Reviews Computational Molecular Science, 3(1), 13-20. 

The intramolecular nonbonded interactions in C1-C(N02)3 are electrostatic but do not involve o-holes. Now we will consider some instances of group IV and group VI intramolecular o-hole interactions. 

Politzer P, Mmray JS, Clark T (2013) Halogen bonding and other o-hole interactions a perspective. Phys Chem Chem Phys 15 11178-11189... 

Politzer P, Riley KE, Bulat FA, Murray JS (2012) Perspectives on halogen bonding and other o-hole interactions lex parsimoniae (Occam s Razor). Comp Theor Chem 998 2-8... 

In the sudden approximation, the satellite intensity Increases with change in the hybridization between the v and cv states. In the ground v state, the hole is primarily in the d orbital, in the primary cv state it is mostly in the p orbital. However, some hybridization still occurs among the cv states, since the large width of the primary cp peak is believed to arise from the mixing with the cd state. The cd state has a large width due to the large core-hole, valence-hole interaction, indeed, the satellite actually reveals the cd multiplet structure. Evidence that the primary cp peak width arises from the cd interaction comes from the Cu halide data (8), as well as the different Cu oxide data in Pig. 2a, which show a direct correlation of the primary cp peak width with the satellite cd peak intensity. We do not believe that the primary peak width arises from the O p band width as proposed by others (34). 

Many examples of such anisotropic MEP distributions have been described in the past five years [11, 12, 14-17, 30]. They can aU be expected to result in some directional preference for purely Coulomb interactions, but those in which the effects of o-holes and p-lone pairs are combined wiU exhibit the strongest directionality. 

Fig. 16.6 Diagram showing the directionalities of the intramolecular interactions in O—P(CH2C1)3. They involve positive o-holes on the phosphorus, along the extensions of the 0-P and C-P bonds, and the negative sides of the chlorines...

The mentioned here dual character of atoms of Groups V-VII, i.e. that o-holes are found in conjunction with regions of the negative electrostatic potential, results in the existence of interactions between symmetrically equivalent atoms. Thus the halogen-halogen (dihalogen) bonds [60] are observed as well as... 

FIGURE 9.4 (See color insert.) Double interactions of the FHjP—PH F dimer. On top are surface electrostatic potential plots of the two PHjF molecules showing the electrostatic forces driving the double interactions. The strong (red) positive o-hole of each phosphorus interacts with the negative region of the other phosphorus, as indicated by the lines. Below is a structural drawing of the FH P—PH F dimer. 

The contraction of the Si-O-N angle in molecules such as (4) has been danon-strated to be the result of the attraction between the lone pair of nitrogen and silicon s positive o-hole on the extension of the X-Si bond [109], (This is the o-hole that is best positioned to interact with the nitrogen lone pair.) Of lesser importance but still significant are secondary (often repulsive) interactions between the lone pair and the substituents Y and Z. 

Pohtzer, R Murray, J. S. Lane, P. 2007. o-Hole bonding and hydrogen bonding competitive interactions. 7nf. J. Quantum. Chem. 107 3046-3052. 

Murray, J. S Riley, K. E. Pohtzer, R Clark, T. 2010. Directional weak intermolecular interactions o-hole bonding. Awsf. J. Chem. 63 1598-1607. 

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