A Cambridge Structural Database analysis of the C-H•••Cl interaction:: C-H•••Cl- and C-H•••Cl-M often behave as hydrogen bonds but C-H•••Cl-C is generally a van der Waals interaction

A survey of organic crystal structures in the CSD for C-H . . . Cl contacts with Cl-M, Cl- and Cl-C acceptor moieties shows the inverse distance-angle correlation characteristic of a hydrogen bond for C-H . . . Cl-M and C-H . . . Cl- type interactions. The d-theta scatter plot for the C-H . . . Cl-C interaction has many points in the van der Waals region. Further, the H . . . Cl bond is shorter with activated donors for Cl-M and Cl- acceptors but not for Cl-C. These frequency data may be useful to classify C-H . . . Cl interactions as hydrogen bonds or van der Waals interactions in crystal structure analysis.