Cerium(IV) Catalysts for the Ring-Opening Polymerization of Lactide
作者:Erin M. Broderick、Paula L. Diaconescu
DOI:10.1021/ic802047u
日期:2009.6.1
A rare example of a cerium(IV) alkoxide catalyst for lactidepolymerization is reported. The lactidepolymerization activity of the new cerium(IV) complex supported by a ferrocene Schiff base ligand, salfen, is compared to the activity of the yttrium analogue and to that of Ce(OtBu)4(THF)2. The complex Ce(salfen)(OtBu)2 is less active than Ce(OtBu)4(THF)2 and the corresponding yttrium(III) alkoxide
据报道,用于丙交酯聚合的铈(IV)醇盐催化剂的稀有实例。将二茂铁席夫碱配体salfen支撑的新铈(IV)配合物的丙交酯聚合活性与钇类似物和Ce(O t Bu)4(THF)2的活性进行了比较。Ce(salfen)(O t Bu)2复合物的活性低于Ce(O t Bu)4(THF)2和相应的钇(III)醇盐Y(salfen)(O t Bu)(THF)的活性。两种活性的不同活性与通过密度泛函理论计算的Mulliken电荷相关。
Chloride abstraction activity of Ce(IV) nitrate and alkoxide complexes: Facile formation of [CeCl5(THF)][CeClZ(THF)5] (Z=NO3, Cl)
作者:William J. Evans、Laurie A. Edinger、Joseph W. Ziller
DOI:10.1016/s0277-5387(99)00008-x
日期:1999.3
Ce(OCMe3)(2)(NO3)(2)(THF)(2) and Ce(OCMe3)(NO3)(3)(THF)(2) react with chlorotrimethylsilane in tetrahydrofuran (THF) at room temperature to form [CeCl(NO3)(THF)(5)] [CeCl5(THF)], 1, and [CeCl5(THF)(5)][CeCl5 (THF)], 2. Ce(OCMe3)(4)(THF)(2) is less reactive under the same conditions but was found to form a salt involving a [CeCl5(THF)](-) anion. Ceric ammonium nitrate, [(NH4)(2)Ce(NO3)(6)], does not form these polychlorinated species under these conditions. 1 crystallizes from THF to form an octahedral [CeCl5(THF)](-) anion and a pentagonal bipyramidal [CeCl(NO3)(THF)(5)](+) cation, which has chloride and nitrate in the axial positions. (C) 1999 Elsevier Science Ltd. All rights reserved.