Synthesis and crystal structures of exo-polyhedral cyclized nickelaundecaborane clusters

Four nickelaundecaborane clusters have been isolated from the reaction of [ NiCl2 (PPh3)(2)] with B10H102- in the present of PhCOSH. Three of them [(PP h3)(PhCOS)(2)NiB10H10] . 0.5C(6)H(14)(1), [(PhCOS)(2)NiB10H8 (PPh3)](2),[(P hCOS)(3)NiB10H7 (PPh3)] (3)were characterized by X - ray diffraction analys is, The clusters have nido 11 - vertex {NiB10} polyhedral skeletons with tw o, two and three exo - polyhedral cyclic Ni-S-C-O-B five - membered rings, respectively, The distance between boron atoms participating in exo - polyh edral cyclizations to nickel atom is shorter which shows that cyclization c an strengthen the nickel - to - boron bonding.