text: The first organoniobium compound fully characterized was , however the paramagnetic Nb(IV) metallocenes such as niobocene dichloride are more prevalent. Complexes are typically prepared by treatment of  with NaCp to form the bis(cyclopentadienyl) complex followed by further functionalization. Derivatives of pentamethylcyclopentadiene are also known, such as .
  Niobium carbonyls supported by Cp ligands can be prepared at various oxidation states of Nb and serve as useful precursors in niobium carbonyl chemistry.