[Os(η(5)-B(5)H(10))(2)]: A carbon-free analog of ferrocene
Summary
The synthesis of a carbon-free analog of ferrocene has been a long-standing goal in inorganic chemistry. We report here the preparation and crystallographic characterization of the carbon-free sandwich complex Os(η5-B5H10)2, which is qualitatively similar to ferrocene in structure and bonding. The metal-ring bonding is much stronger in Os(η5-B5H10)2, owing to rehybridization of the π molecular orbitals brought in by the bridging B-H-B hydrogens and the bent B-Ht bonds of the larger B5H10 r
Content
# [Os(η(5)-B(5)H(10))(2)]: A carbon-free analog of ferrocene
*Published: 2026 Apr 23*
The synthesis of a carbon-free analog of ferrocene has been a long-standing goal
in inorganic chemistry. We report here the preparation and crystallographic
characterization of the carbon-free sandwich complex [Os(η5-B5H10)2], which is
qualitatively similar to ferrocene in structure and bonding. The metal-ring
bonding is much stronger in [Os(η5-B5H10)2], owing to rehybridization of the π
molecular orbitals brought in by the bridging B-H-B hydrogens and the bent B-Ht
bonds of the larger B5H10 ring (where B-Ht is the terminal B-H bond). This also
leads to an unusually short ring-ring separation of 3.071 angstroms and a
staggered conformation. The isomeric [Os(η5-B5H10)(η3-B5H10)], which features a
coordination mode unknown for ferrocene, has also been isolated. A similar
attempt for [Ru(η5-B5H10)2] resulted only in [Ru(η5-B5H10)(η3-B5H10)].
DOI: 10.1126/science.aed9192