Features of the formation of zinc(II) and cadmium(II) complexes with the inner-sphere and outer-sphere position of the decahydro-closo-decaborate anion in the presence of azaheterocyclic ligands

In the present work, we studied reactions between Cd(II) or Zn(II) salts and the closo-decaborate anion [B10H10]2− in the presence of azaheterocyclic ligands L (L = 2,2′-bipyridyl (bipy), 2,2′-bipyridylamine (bpa), and 1,10-phenanthroline (phen)). It was found that, depending on the nature of organic ligands L, solvents, and synthetic conditions, complexes with the inner-sphere and outer-sphere positions of the boron cluster were formed with different composition and structures. The structure of tris-chelate complex [Zn(bipy)3][B10H10] and mixed-ligand complexes [Zn(bpa)2(NO3)]2[B10H10], [Cd(bipy)2[B10H10]], and [Zn(bpa)2[B10H10]] were studied by X-ray single-crystal diffraction. Compounds [Cd(bipy)2[B10H10]] and [Zn(bpa)2[B10H10]] contain the coordinated boron cluster anion, the latter complex being the first example of a zinc(II) complex with the coordinated boron cluster anion.