Synthesis and Characterization of the First Niobocene Germyl Complexes and Reactivity of Triphenylsilyl-, Triphenylgermyl-, and Triphenylstannylniobocene Derivatives. X-ray Molecular Structures of d0 Nb(η5-C5H4SiMe3)2(H)2(EPh3) (E = Ge, Sn) | Publicación