{(R,S(Fc),S(Fc))-2''-Bromo-2-[1-(dimethyl-amino)-ethyl-κN]-1,1''-biferrocene}trihydridoboron.

The title structure, [Fe(2)(C(5)H(5))(2)(C(14)H(19)BBrN)], contains a chiral and asymmetrically 2,2''-disubstituted biferrocene designed as precursor for enanti-oselective non-C(2)-symmetric biferrocenyldiphosphine catalysts. The mean bond lengths in the biferrocene unit are Fe-C = 2.048 (10) Å and C-C = 1.427 (8) Å within the cyclo-penta-dienyl rings. The B-N bond lengths of the BH(3) protected amine is 1.631 (3) Å. The inter-planar angle between the two connected cyclo-penta-dienyl rings is 54.29 (8)° and the corresponding Fe-Cg-Cg-Fe torsion angle is -52.5°. The conformation of the mol-ecule is stabilized by an intra-molecular C-H⋯Br inter-action.