Reactions of the dianion [1,1,1-(CO)3-2-Ph-closo-1,2-MnCB9H9]2- with transition-metal cations: facile insertion and then extrusion of cluster vertexes.

The manganacarborane dianion in [N(PPh3)2][NEt4][1,1,1-(CO)3-2-Ph-closo-1,2-MnCB9H9] (1b) reacts with cationic transition metal−ligand fragments to give products in which the electrophilic metal groups (M‘) are exo-polyhedrally attached to the {closo-1,2-MnCB9} cage system via three-center two-electron B−H ⇀ M‘ linkages and generally also by Mn−M‘ bonds. With {Cu(PPh3)}+, the Cu−Mn−Cu trimetallic species [1,6-{Cu(PPh3)}-1,7-{Cu(PPh3)}-6,7-(μ-H)2-1,1,1-(CO)3-2-Ph-closo-1,2-MnCB9H7] (3a) is formed, whereas reactions with {M‘(dppe)}2+ (M‘ = Ni, Pd; dppe = Ph2PCH2CH2PPh2) give [1,3-{Ni(dppe)}-3-(μ-H)-1,1,1-(CO)3-2-Ph-closo-1,2-MnCB9H8] (5a) and [1,3,6-{Pd(dppe)}-3,6-(μ-H)2-1,1,1-(CO)3-2-Ph-closo-1,2-MnCB9H7] (5b), both of which contain M‘−Mn bonds. The latter reaction with M‘ = Pt affords [3,6-{Pt(dppe)}-3,6-(μ-H)2-1,1,1-(CO)3-2-Ph-closo-1,2-MnCB9H7] (6), which lacks a Pt−Mn connectivity. Compound 6 itself spontaneously converts to [1-Ph-2,2,2-(CO)3-8,8-(dppe)-hypercloso-8,2,1-PtMnCB9H9] (7b) and thence to [3...