Bulking up CpBIG: A Penta-Terphenyl Cyclopentadienyl Ligand

04 January 2022, Version 1
This content is a preprint and has not undergone peer review at the time of posting.


The modification of cyclopentadienyl ligands with carefully selected substituents is a widely used strategy to tune their steric and electronic properties. We describe the synthesis of an extremely bulky penta-terphenyl cyclopentadienyl ligand (CpT5) by arylation of cyclopentadiene. Deprotonation reactions with various group 1 metals and bases afforded a complete series of alkali metal salts MCpT5 with M = Li to Cs. The compounds were isolated as solvate-free salts, which were characterized by multinuclear NMR spectroscopy, UV-vis spectroscopy and elemental analysis. Single-crystal X-ray diffraction studies on LiCpT5, NaCpT5 (crystallized as a solvate with one THF molecule per formula unit) and KCpT5 revealed the formation of metallocene-like sandwich structures in the solid state.


ligand design
cyclopentadienyl ligands
alkali metals

Supplementary materials

Supporting Information
NMR spectroscopic data of all compounds and crystallographic data (PDF)


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