The synthesis of W–O–M (M = Al, Ti, Ni, Zn) μ–oxo clusters by hydrolysis of tungsten aminoalkoxides and their structural characterisation

• Structures of novel mixed metal oxo-clusters involving W–O–M (M = Ti, Zn, Al, Ni).
• Isomorphic forms of W2M2O6 cages identified for M = Ti, Al.
• W2Zn2O5 adopts a related “broken” W2M2O6 cage.
• M = Ni species incorporates a novel [WNiO]4 square.

Three novel heterobimetallic W–O–M clusters have been synthesised by the hydrolysis of mixtures of W(O)(OPri)3(bdmap) with Ti(OPri)4, Zn(acac)2 and Al(OPri)3, respectively. A fourth, related W–O–Ni cluster has been obtained by adventitious hydrolysis of a mixture of W(O)(OMe)4 and Ni(dmap)2 [Hbdmap = 1,3-bis-(dimethylamino)-propan-2-ol; Hdmap = 1-(dimethylamino)propan-2-ol]. W2Ti2(O)2(μ2–O)4(OPri)6(μ2–bdmap)2 (1) adopts a central W2Ti2O6 core with an adamantane-like structure while W2Al2(O)2(OPri)2(μ2–O)4(μ2–bdmap)4 (3) has an analogous W2Al2O6 core but which adopts an isomeric cube arrangement with two parallel sides missing. W2Zn2(O)2(μ2–O)3(OPri)2(acac)2(μ2–bdmap)2 (2) is similar to 1 but the two bidentate acac groups result in the elimination of one μ2–O bridge; the resulting W2Zn2O5 core forms an adamantane structure with one W–O–Zn linkage missing. In contrast, W4Ni4(O)4(OMe)4(μ2–OMe)4(μ2–O)4(dmap)8 (4) forms a tetrameric square of four linked W–O–Ni units.

The structures of four novel heterobimetallic W–O–M oxo-clusters W2Ti2(O)2(OPri)2(μ2–O)4(OPri)6(μ2–bdmap)2, W2Zn2(O)2(μ2–O)3(acac)2(μ2–bdmap)2 W2Al2(O)2(OPri)2(μ2–O)4(μ2–bdmap)4 (3) and W4Ni4(O)4(OMe)4(μ2–OMe)4(μ2–O)4(dmap)8 have been determined.Figure optionsDownload as PowerPoint slide