Competition and cooperation: hydrogen and halogen bonding in co-crystals involving 4-iodotetrafluorobenzoic acid, 4-iodotetrafluorophenol and 4-bromotetrafluorophenol??

CrystEngComm Pub Date: 2014-04-09 DOI: 10.1039/C4CE00319E

Abstract

Co-crystallisation of 4-iodotetrafluorobenzoic acid with 1,4-dithiane leads to a polymer in which the benzoic acid dimer remains intact, forming halogen bonds with the dithiane, showing that considering both pKb and the iodine basicity scale (pKBI2) can direct the structure formed. Crystallisation of 4-halotetrafluorophenols with 1,4-dithiane or tetrahydrothiophene was always accompanied by oxidation to the S-oxide or S,S′-dioxide and in two cases the co-crystals formed involved hydrogen bonding (4-bromotetrafluorophenol) and both hydrogen and halogen bonding (4-iodotetrafluorophenol). Co-crystallisation of 4-iodotetrafluorophenol with 4,4′-bipyridine leads to a linear polymer with both hydrogen and halogen bonding.

Graphical abstract: Competition and cooperation: hydrogen and halogen bonding in co-crystals involving 4-iodotetrafluorobenzoic acid, 4-iodotetrafluorophenol and 4-bromotetrafluorophenol
Recommended Literature