dodecacarbonyl(iron)carbide butterfly

Other names: tetra-iron dodecacarbonyl carbide

[Fe₄(CO)₁₂C]^2-

42/50 uncommon

The dodecacarbonyl(iron)carbide butterfly is a fascinating organometallic cluster featuring four iron atoms arranged in an unusual C_2v non-VSEPR geometry around a central carbon atom. First characterized by in 1982, this unusual dianion complex demonstrates remarkable metal-carbon bonding patterns. The structure consists of two Fe₂C triangular faces joined at the carbon atom, creating a distinctive butterfly or bow-tie shape, with twelve carbonyl (CO) ligands distributed around the iron atoms. This complex serves as an important model system for understanding carbon-metal bonding in larger cluster compounds and has been studied for potential applications in catalysis, particularly for reactions involving carbon monoxide activation. The butterfly structure represents a compelling example of how carbon can adopt unusual bonding environments within transition metal clusters.