Syntheses of heteronuclear molybdenum/bismuth alkoxides stabilized by organic ligands

Reaction of [((CH3)C3H4)Mo(CO)(2)(CH3CN)(2)Cl], 2, with [Bi(OEt)(3)](x) pro vides the heterotetranuclear complex [((CH3)C3H4)Mo(CO)(2)(mu-OEt)(3)Bi(mu- OEt)(2)Bi(mu-OEt)(3)Mo(CO)(2)((CH3)C3H4)], 3, in good yields. If 2 is react ed with [Bi(OCH2CH2OCH3)(3)](2), a dinuclear chloro alkoxide [((CH3)C3H4)Mo (CO)(2)(mu-kappa O,2 kappa O'-OCH2CH2OCH3)(2)(mu-Cl)BiCl], 4, is obtained, while pretreatment of 2 with AgBF4 and subsequent reaction with [Bi(OCH2CH2 OCH3)(3)](2) leads to the chloride-free complex [((CH3)C3H4)Mo(CO)(2)(mu-ka ppa O'-OCH2CH2OCH3)(3)Bi(thf)][BF4], 6, with a Bi center surrounded by seve n oxygen donors. All compounds have been characterized by NMR and IR spectr oscopy as well as elemental analysis, and their crystal structures were det ermined by means of single-crystal X-ray diffraction. 3, 4, and 6 belong to the few compounds known (there is only one other precedent) where Mo and R i centers are bridged by oxygen-containing ligands and can therefore be con sidered as cornerstones on the way to the synthesis of yet unknown molecula r compounds with Mo-O-Bi functions resembling those occurring on the surfac e of nMoO(3)-Bi2O3 catalysts.