Facile displacement of cyclohexadienide ligand from K[Cr(η5-C6H7)(CO)3] to give crystallographically characterized trans-[Cr(CO)4(PPh3)2]

Substitution of K[Cr(η5-C6H7)(CO)3] with triphenylphosphine resulted in cyclohexadienide loss and formation of an unexpected product, trans-[Cr(CO)4(PPh3)2]. The structure of this complex was determined by single crystal X-ray diffraction. Crystals contain two conformational isomers, differing mainly in the orientation of PPh3 ligands.