Halogen bonding, interactions

Scheme 8 The two main types of halogen bond interactions...

Fig. 11 The trimeric motif formed upon halogen bonding interaction between the partially oxidized EDT-TTF-I2 and the dithiolene complex [NilmnthF...

Recently, the ability of halogenated TTFs to enter into halogen bond interactions was also extended to other families of donor molecules such as the dithiapyrenes (DTPYs) (Scheme 12) [92], The better solubility of... 

This short review has demonstrated that halogen bonding interactions have already been used in many ways in the field of magnetic or conducting organic systems. Only a few examples are available in the nitroxide family, but... 

K. Riley et al., Br—O complexes as probes of factors affecting halogen bonding Interactions of bromobenzenes and bromopyrimidines with acetone. J. Chem. Theor. Comput. 5, 155-163 (2009)... 

M. Fourmigue, P. Batail, Activation of hydrogen- and halogen-bonding interactions in tetra-thiafulvalene-based crystalline molecular conductors. Chem. Rev. 104, 5379-5418 (2004)... 

Finally, we briefly report another interaction not very different from the hydrogen bonding interaction, involving amines and in particular anilines the halogen bond interaction. 

Riley, K. E. Murray, J. S. Fanfrlik, J. Rezac, J. Sola, R. J. Concha, M. C. Ramos, F. M. Pohtzer, P. 2011. Halogen bond tenability I. The effects of aromatic fluorine substitution on the strengths of halogen-bonding interactions involving chlorine, bromine and iodine. J. Mol. Model. 17 3309-3318. 

Figure 4.22 (a) Some examples of halogen bonding interactions (X = halogen) and their use within the structures of (b) 4-nitro-4 -iodobiphenyl and (c) [PtCl2(CsNH4Br)2] (X = Cl, Br and I). 

Figure 5 Line drawing and X-ray molecular structure of a podand host for Nal acting via halogen bonding interactions...

The following overview of halogen-bonded cocrystals uses a classification of motifs as being OD, ID, 2D, or 3D based on the primary halogen bond interactions. 

Zhu X, Lu Y, Peng C, Hu J, Liu H, Hu Y Halogen bonding interactions between bromi-nated ion pairs and CO2 molecules impHcations for design of new and efficient ionic Hquids for CO2 absorption, J Phys Chem B 115(14) 3949—3958, 2011. 

Hauchecome D, Szostak R, Herrebout WA, van der Vekken BJ (2009) CX---0 Halogen bonding interactions of trifluoro- methyl halides with dimethyl ether. Chem Phys Chem 10 2105-2115... 

Fig. 32.22 Line drawing structure of cavitand units 57 and 58, and self-assembled heterodimeric capsules 59. The energy minimized structure of the encapsulation complex formed by three guests 60 in the cavity of the self-assembled container 59d (57d 58) stabilized by four halogen bond interactions is also shown...

The interactions present in halogen-bonded systems are in general weak, thus the need to use quantum mechanical methods that include electron correlation for an accurate description. In particular, these interactions are sensitive, not only to the basis set used but also to the level of electron correlation used, the counterpoise correction and the inclusion of spin-orbit effects for bromine and iodine. In contrast with the widely accepted idea that hydrogen bonded systems are reasonably well described with MoUer-Plesset perturbation (MP2) methods, halogen bond interactions are overestimated at this level. Therefore, for an accurate description of these systems a coupled cluster method is advised, preferably with single and double excitations (CCSD) or with perturbative triple excitations (CCSD(T)). This problem pertains also to density functional theory methods (DFT) where some methods lead to better results than others and the choice of the best functional is not straightforward. DFT methods have the advantage over wave function methods that time... 

---