Half sandwich compound

As a half-sandwich complexes is understood in a broad sense those metallocene compounds that have bound only a cyclopentadienyl system via π - bonds to a central metal atom. The saturation of free (electron ) valencies is via carbonyl groups (such as tricarbonyl ( η5 -cyclopentadienyl ) manganese ), nitroso groups or other hetero-atoms (for example iodine). Due to their shape, these compounds are also referred to as piano-stool complexes.

Tricarbonyl ( η5 -methylcyclopentadienyl ) manganese

Dicarbonyl ( η5 - cyclopentadienyl) iodoeisen (II )