Synthesis and molecular structure of [Fe3(μ2-H)(μ3-Te)(CO)9][Cp#2Nb(CO)2] (Cp#=C5Me5, C5Me4Et)

Reaction of [Cp#2Nb(Te2H)] (1#) (Cp#=Cp* (C5Me5) or Cpx (C5Me4Et)) with [Fe2(CO)9] in boiling toluene gives [Fe3(μ2-H)(μ3-Te)(CO)9][Cp#2Nb(CO)2] (2) (Cp#=Cp*) and (3) (Cp#=Cpx) in 33 and 39% yield, respectively. The crystal structure of 3 contains the already known [Fe3HTe(CO)9]− anion and a [Cpx2Nb(CO)2]+ cation in a 1:1 ratio. The latter belongs to the class of bent metallocenes in which the Nb(CO)2 plain bisects the cation. For the first time, localization of the hydrogen in the solid state as a μ2-bridge in the cluster anion has been established.