4 In principle, each non‐metallic element of the periodic table could be involved in σ‐hole interactions, provided the atom is placed in the appropriate molecular framework. The ultimate conclusion of a strong σ‐hole donor‐acceptor interaction can be the breaking and/or making of a σ bond, such as in the reaction of I 2 with I − to form −. The location of this potential coincides with the σ* orbital of that bond. 3 A σ‐hole can be seen as region of electropositive potential along the vector of a covalent bond. 1 Such interactions include hydrogen and halogen bonding, 1a, 2 which have recently been contextualized as examples of so‐called ‘σ‐hole interactions’. Phenomena such as host‐guest complexation, molecular aggregation, crystallization and protein folding are often largely driven by non‐covalent interactions.
0 kommentar(er)
