En el presente trabajo describimos el estudio de estas reacciones aplicadas a la preparación de derivados del sistema TpW (CO)z -L (L =ligando organometálico con elementos del IV grupo principal), con el objeto de comparar el componarniento del sistema del tungsteno con el del molibdeno, en parte estudiado por nosotros anteriormente. / We report the reactions of TpW(COh X (Tp = h7-C7H 7, X = Br, 1)with thc anionic species MPh3 - (Ph = C6 Hs ; M= Ge, Sn, Pb) leading to thesubstitution products TpW(C0hMPh3 (3). The compound 3d (M= Pb) couldnot be isolated due to its instability and was only detected spcctroscopically;3b (M= Ge) and 3c (M = Sn) were isolated as red crystals and caracterizedthrough elemental analysis and spectrometry (IR, 1H-NMR and MS).The reduction of TpW(COhl with Na/Hg in THF leads to the an10n[TpW (COhr (1), which also reacts with MPh3- (M = Si, Ge, Sn) forming3a (M = Si), 3b and 3c; 3a was detected only spectroscopically.