Three new types of transition metal carboranylamidinate complexes

Three new types of transition metal carboranylamidinate complexes are reported. The tetranuclear Mn(II) complex Mn4Cl6[(o-C2B10H10)C(NiPr)(NHiPr)]2(THF)4·THF (2) was prepared by treatment of anhydrous MnCl2 with Li[(o-C2B10H10)C(NiPr)(NHiPr)] (Li[HLiPr]) in THF, while the analogous reaction with FeCl2 afforded ionic [Li(DME)3][FeCl2{(o-C2B10H10)C(NiPr)(NHiPr)}] (3). The dinuclear Mo(II) complex Mo2[(o-C2B10H10)C(NiPr)(NHiPr)]2(OAc)2·2THF (4), obtained from Mo2(OAc)4 and 2 equiv. of Li[HLiPr], represents the first example of a M–M multiple bond stabilized by carboranylamidinate ligands. All title compounds were structurally characterized by single-crystal X-ray diffraction. The M–M bonding in compound 4 has been further elucidated through Complete Active Space Self Consistent Field (CASSCF) calculations.