Halogen bonds in the solid state have been investigated for many years but there has been a major resurgence in this area in the last decade. The emphasis of most of these studies has been on organic based halogen bonds. However, in their Highlight for CrystEngComm, Lee Brammer and colleagues focus on inorganic halogen bonds and show that halogen bonds are pervasive across the periodic table, not just in organic molecules. 

The authors discuss the results of a survey of structures currently in the Cambridge Structural Database (CSD) which have interactions which are of a suitable geometry to be considered as halogen bonds. In particular, they looked at monatomic (e.g. oxo, nitride) and diatomic (e.g. carbonyl, cyanide) ligands as halogen bond acceptors and main group metals, as well as transition metals, are considered. 

'The aim of this survey is to examine the breadth of elements that can be involved in halogen bonding involving at least one inorganic (metal-contining) component,' says Brammer. He goes on to say that the study will form a 'basis for future research in halogen bonding with applications in crystal engineering and allied areas'.