Reactivity of niobium and tantalum pentahalides with cyclic ethers and the isolation and characterization of intermediates in the polymerization of tetrahydrofuran |
| |
Authors: | Marchetti Fabio Pampaloni Guido Zacchini Stefano |
| |
Institution: | Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via Risorgimento 35, I-56126, Pisa, Italy. |
| |
Abstract: | The complexes MX5(THF) (M = Nb, X = Cl, 2a; M = Ta, X = F, 2c, X = Cl, 2d) and MX4(THF){O(CH2)4O(CH2)3CH2)}]MX6] (M = Nb, X = Cl, 3a; M = Ta, X = Cl, 3d, X = Br, 3e, X = I, 3f) result from reactions of MX5 with 0.5 and 1.5 equiv of THF, respectively. Compounds 3 contain the unprecedented 4-(tetrahydrofuran-1-ium)-butan-1-oxo ligand and are likely to play a role in the course of THF polymerization catalyzed by MX5. The addition of L (L = 2,5-dimethyltetrahydrofuran, tetrahydropyran, 1,4-dioxane) to MX5 results in the formation of the hexacoordinated complexes MX5(L). The molecular structures of 2d, 3d, and NbCl5(dioxane), 6a, have been ascertained by X-ray diffraction studies. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |
|