Dehydration of scandium chloride hydrate: synthesis and molecular structures of ScCl3(η2-DME)(MeCN), ScCl3(diglyme) and [Sc2(μ-OH)2(H2O)10]Cl4·2H2O
作者:Valérie Ripert、Liliane G. Hubert-Pfalzgraf、Jacqueline Vaissermann
DOI:10.1016/s0277-5387(99)00063-7
日期:1999.5
Various dehydration procedures have been evaluated for ScCl3. 6H(2)O, The ScCl3(DME)(MeCN) 1 and ScCl3(diglyme) 2 [diglyme=MeO(CH2CH2O)(2)Me] adducts have been synthesized by a ligand-exchange reaction from ScCl3(THF)(3) in acetonitrile. The diglyme adduct could also be obtained by dehydration of ScCl3. 6H(2)O by trimethylchlorosilane in diethylether in the presence of the ligand. The complexes were characterized by FT-IR, H-1 NMR and by X-ray diffraction. They both correspond to monomeric species based on distorted hexacoordinated scandium. Hydrolysis of 2 gave [Sc-2(mu-OH)(2)(H2O)(10)]Cl-4. 2H(2)O, 3. The Sc-O coordination bonds of 1 and of 2 [2.207(1) Angstrom for the DME adduct, 2.165(8)-2.257(9) Angstrom for 2] have lengths comparable to the Sc-O(H2O) bonds of 3 [2.172(4)-2.217(5) Angstrom], but were longer than the Sc-OH ones [2.064(5) Angstrom]. The dimeric cations, in which the metals are heptacoordinated, are associated by hydrogen bonding (similar to 2.737(5) Angstrom) between coordinated and crystallization-type water molecules. As a result, chains are developed along the a axis. (C) 1999 Elsevier Science Ltd. All rights reserved.