RESUMO
Readily accessible and easy-to-use phenyliodine(III) dichloride, PhICl(2), has been established as an innovative and superior reagent for the one-electron oxidation of cerium(III) complexes, comprising amide, amidinate, and cyclopentadienyl derivatives. Its use allowed the successful synthesis and structural characterization of the first members of three new classes of chloro-functionalized (organo)cerium(IV) compounds, including the long sought-after Cp(3)CeCl.
Assuntos
Cério/química , Elétrons , Indicadores e Reagentes/química , Iodo/química , Modelos Moleculares , Estrutura Molecular , OxirreduçãoRESUMO
The heteroleptic tetravalent cerium complex [Ce(OiPr)3{N(SiMe3)2}]2 was synthesised by treating ceric ammonium nitrate (CAN) sequentially with sodium isopropoxide and lithium bis(trimethylsilyl)amide in THF. The trivalent ate complex [Ce(OiPr)2{N(SiMe3)2]2}][Li(thf)2] was also isolated from these reaction mixtures. A transsilylamination reaction of [Ce(OiPr)3{N(SiMe3)2}]2 with tetramethyldisilazane produced a considerable amount of homoleptic Ce[N(SiHMe2)2]4. The polymeric complex [Li2Ce2(OiPr)10(1,4-dioxane)]n was isolated as an additional ligand redistribution product. When tetravalent complexes Ce[N(SiHMe2)2]4, Ce[N(SiMe3)2]3Cl and Cp3CeCl were allowed to react with samples of periodic mesoporous silica MCM-41, Ce(iv) hybrid materials were produced. All hybrid materials were characterised via N2 physisorption, elemental analysis and DRIFT spectroscopy.
RESUMO
Treatment of Ce[N(SiHMe(2))(2)](3)(thf)(2) with the chlorinating agents PhICl(2), Ph(3)CCl or C(2)Cl(6) gave the homoleptic Ce(IV) silylamide Ce[N(SiHMe(2))(2)](4). When performed in the absence of donating (solvent) molecules, the trivalent cluster Ce(5)[N(SiHMe(2))(2)](8)Cl(7) was isolated.