Intermolecular interactions halogens

Brinck, T., J. S. Murray, and P. Politzer. 1992b. Surface Electrostatic Potentials of Halogenated Methanes as Indicators of Directional Intermolecular Interactions. Int. J. Quant. Chem., Quant. Biol. Symp. 19, 57. 

The improved understanding of the interplay of different types of intermolecular interactions should, however, allow in future also supramolecular architecture with heavier chalcogen-halogen interactions. 

While the boiling points of chloro- and bromomethanes always increase according to the number of halogen atoms, this correlation does not exist in the case of fluoromethanes. The bp increases from CH4 to CH2F2 and then decreases until CF4 (Table 1.4). Indeed, a parallelism exists between boiling points and dipolar moments. A partially fluorinated compound will exhibit nonnegligible intermolecular interactions according to the importance of the dipolar moment (Table 1.5). ... 

Solvatochromic Approach Solvatochromic relationships are multivariate correlations between a property, usually solubility or partitioning property (see Sections 11.4 and 13.3), and solvatochromic parameters, parameters that account for the solutes interaction with the solvent. In the case of vapor pressure, the solvatochromic parameters only have to account for intermolecular interaction such as selfassociation between the solute (i.e., pure compound) molecules themselves. The following model has been reported for liquid and solid compounds, including hydrocarbons, halogenated hydrocarbons, alkanols, dialkyl ethers, and compounds such as dimethyl formamide, dimethylacetamide, pyridine, and dimethyl sulfoxide... 

T. Brinck et al., Surface electrostatic potentials of halogenated methanes as indicators of directional intermolecular interactions. Int. J. Quantum Chem. 44, 57-64 (1992)... 

Intermolecular interactions or packing effects in the solid state may influence geometries considerably. This effect on carbon-halogen bond distances, however, can be assumed to be small (< 1 pm). 

The question still remains if the acidic hydrogen is the only important associative factor in the molecules that contain one or if the halogens too play an important role. Furthermore we have to examine the nature of possible intermolecular interactions in the case of molecules containing no acidic hydrogen ... 

While the brunt of intermolecular interactions is expected to be carried by the acidic hydrogen for these molecules, it is still of importance to gain knowledge on the possible role of the halogens. That the addic hydrogens enter hydrogen bonds is, of course, well known ... 

The intermolecular association leads to the formation of coordination polymers. The crystal structures of the phenylantimony dihalides have been determined at — 120 °C. The three dihalides crystallize in the same type of crystal structure, i.e. isotypically. There is intermolecular association not only through antimony/halogen contacts but also through / -arene interaction. These interactions lead to a two-dimensional network. The intermolecular antimony/halogen contacts are shorter than the sum of van der Waals radii of Sb (220 pm), and Cl (170-190), Br (180-200) or I (195-212) respectively. The intermolecular interactions of phenylantimony dichloride, dibromide and diiodide are not very strong... 

The Nature and Geometry of Intermolecular Interactions Between Halogens and Oxygen or Nitrogen. 

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