The competition between halogen bonds (Br center dot center dot center dot O) and C-H center dot center dot center dot O hydrogen bonds: the structure of the acetone-bromine complex revisited

作者：Jones R H^*; Knight K S; Marshall W G; Coles S J; Horton P N; Pitak M B

来源：CrystEngComm, 2013, 15(42): 8572-8577.

DOI：10.1039/c3ce41472h

A combination of single-crystal X-ray (at 110 and 200 K) and high-resolution neutron powder diffraction (110 K only) using perdeuterated samples has been used to re-determine the crystal structure of the well-known acetone-Br-2 complex. The results indicate a significant interaction between the carbonyl oxygen and the nearest Br atom leading to a marked elongation of the molecular Br-Br bond. In the earlier widely cited crystal structure, no such elongation was reported. Furthermore, the new structure indicates the presence of additional weaker C-H center dot center dot center dot O and C-H center dot center dot center dot Br interactions. In this simple complex, in which the halogen bonding is strong compared to the hydrogen bonding (C-H center dot center dot center dot O), the former interaction is found to occur close (similar to 12 degrees) to the plane of the carbonyl group, with the C-H center dot center dot center dot Br complementing the stronger halogen bond.

• 出版日期2013