Carbaboranylnickel Complexes with the Novel η 5 ‐2,3,5‐Tricarbahexaboranyl Ligand

Multilayer sandwich complexes containing the novel ligands 1b and 1c have been obtained by unusual boranediyl transfer and stacking reactions. Reaction of Ni(allyl) 2 with 2b leads to formation of trace amounts of the complexes [ 1b Ni 2b ] and [ 1b Ni 2b Ni 1b ]. Also [ 1b Ni 2b Ni 2b Ni 1b ] could be obtained from the primary product [ 2b Ni 2b ]. [ 2c Ni 2c ] reacts analogously; the ligand 2a in [ 2a Ni 2a ], on the other hand, is sterically too well shielded for boranediyl‐transfers.