Stabilization of Diatomic Interhalogens by Lewis Bases

Computational studies reveal significant stabilization of diatomic interhalogen complexes BrCl, ICl, IBr with respect to complexes with homonuclear dihalogens both in the gas phase and in nonaqueous solutions. This opens an easy pathway for the synthesis of interhalogen complexes by mixing halogens in the presence of Lewis bases. The approach was experimentally verified by the synthesis of a series of interhalogen complexes with HMTA (IBr, ICl, BrCl) and pyridine (IBr, ICl) directly from elemental halogens. The IBr·HMTA and (IBr)2·HMTA complexes were structurally characterized by single-crystal X-ray diffraction. The remaining complexes were identified by powder X-ray diffraction.