C-halogen center dot center dot center dot O supramolecular synthons: in situ cryocrystallisation of 1,2-dihalotetrafluoroethane/HMPA adducts

The in situ cryocrystallisation technique has been used to obtain four
adducts between hexamethylphosphortriamide and
1,2-dihalotetrafluoroethanes having iodine, bromine and chlorine as
halogen-bonding donor atoms. These systems allowed for a precise
comparison of different C-X...O synthons. The effectiveness and
reliability of the pharmacologically important C-Cl...O synthons are
proven.