RT info:eu-repo/semantics/article T1 Bromodicyclopentadienylniobium complexes A1 Acedo Peque, Lucía A1 Otero Montero, Antonio A1 Royo Gracia, Pascual K1 Bromodicyclopentadienylniobium K1 Ciencia K1 Química inorgánica K1 Science K1 Chemistry, inorganic AB The reaction of NbX5 (X=Cl, Br) with an excess of NaCp (Cp=C5H5) followed by the addition of HBr gives (η5-C5H5)2NbBr2 (I) in low yield. The reduction of I with Na/Hg or NaNaph in a molar ratio 1/1 gives (η5-C5H5)2NbBr (II), whereas the same reaction in the presence of π-acid ligands gives (η5-C5H5)2NbBrL (III, L=CO; IV, L=PMe2Ph; V, L=P(OMe)3; VI, L=PhC≡CPh; VIII, L=PhC≡CH). Finally, the reduction of I with Na/Hg in a molar ratio 2/1 gives the dimer (η5-C5H5)4Nb2Br3 (VIII), which contains both niobium(III) and niobium(IV). The chemical and structural characteristics of all these compounds are described. PB Elsevier SN 0022-328X YR 1983 FD 1983 LK http://hdl.handle.net/10017/4802 UL http://hdl.handle.net/10017/4802 LA eng NO Comisión Asesora de Investigación Científica y Técnica DS MINDS@UW RD 28-mar-2024