Transition-Metal-Mediated Cleavage of a Si=Si Double Bond

Reaction of carbene-stabilized disilicon (1) with Fe(CO)5 gives the 1:1 adduct L:Si=Si[Fe(CO)4 ]:L (L:=C{N(2,6-Pr(i) 2 C6 H3 )CH}2 ) (2) at room temperature. At raised temperature, however, 2 may react with another equivalent of Fe(CO)5 to give L:Si[μ-Fe2 (CO)6 ](μ-CO)Si:L (3) through insertion of both CO and Fe2 (CO)6 into the Si2 core, which represents the first experimental realization of transition metal-carbonyl-mediated cleavage of a Si=Si double bond. The structures and bonding of both 2 and 3 have been investigated by spectroscopic, crystallographic, and computational methods.