Molecular Pair Analysis: CH⋅⋅⋅F Interactions in the Crystal Structure of Fluorobenzene? And Related Matters

Abstract

Abstract The crystal structure of fluorobenzene is compared with isomorphous crystal structures of molecules of roughly similar shape. The lowest‐energy fluorobenzene dimers are identified by theoretical calculations. Molecular pair analysis of the crystal structure of fluorobenzene and of an isomorphous virtual low‐energy polymorph of benzene suggests that the important intermolecular interactions in the two structures are closely similar. In particular, the intermolecular CH⋅⋅⋅F interactions in the fluorobenzene crystal have approximately the same structure‐directing ability and influence on the intermolecular energy as the corresponding CH⋅⋅⋅H interactions in benzene. Molecular pair analysis of the isomorphous crystal structures of benzonitrile, alloxan, and cyclopentene‐1,2,3‐trione indicates that essentially the same crystal structure can be adopted with quite different patterns of pair energies and atom–atom interactions. The question as to whether the packing radius of organic fluorine is larger or smaller than that of hydrogen, is addressed, but not answered.

Keywords

Affiliated Institutions

• ETH Zurich CH

Related Publications