Features of Intermolecular Interactions in the Structures of Mn, Tc, and Re Carbonyl Halides

Intermolecular interactions in the known mono-, bi-, tri-, and tetranuclear manganese, technetium, and rhenium carbonyl halides were analyzed using the method of molecular Voronoi–Dirichlet polyhedra. The topology of transition metal (M) sublattices in dimeric carbonyl halides [MХ(CO)4]2 was examined in terms of the Voronoi–Dirichlet polyhedra. This analysis has proved that such complexes with X = Cl or Вr are isostructural but differ from the related iodides, which, in turn, are isostructural to each other irrespective of the kind of M. Similar pattern is observed for mononuclear complexes [MХ(CO)5]. The size effect is considered as the main cause of the change in the crystal structure in going from X = Cl and Br to X = I. No convincing evidences of specific intermolecular interactions involving halide ligands (halogen bonds) have been found.