Cyclopentadienylnickel Chelates with Secondary or Tertiary Phosphane Tethers Bearing Imidazol‐2‐ylidene Ligands

Treatment of cyclopentadienylnickel chloro or bromo chelates bearing either a tertiary 2‐(di‐ tert ‐butyl)phosphanylethyl or a secondary 2‐(2,4,6‐trimethylphenyl)phosphanylethyl tether with imidazolylidene (Arduengo carbene) ligands results in cationic or electroneutral carbene complexes with either a decoordinated or a chelated tether. The outcome depends on the nature of the carbene, the counter anion, and the reactant stoichiometry. The results are the basis of ongoing investigations directed towards a deprotonation of the chelated cationic complexes with a secondary phosphorus atom.