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Ceric Cyclopentadienides Bearing Alkoxy, Aryloxy, Chlorido, or Iodido Co‐Ligands
Author(s) -
Schneider David,
Harmgarth Nicole,
Edelmann Frank T.,
Anwander Reiner
Publication year - 2017
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201700743
Subject(s) - chemistry , alkoxide , cerium , cyclopentadienyl complex , medicinal chemistry , alkoxy group , metathesis , benzoquinone , iodide , salt metathesis reaction , reactivity (psychology) , inorganic chemistry , catalysis , alkyl , polymerization , organic chemistry , medicine , polymer , alternative medicine , pathology
A series of heteroleptic tris(cyclopentadienyl) Ce IV complexes has been isolated and crystallographically characterized, revealing the broad accessibility of such organocerium(IV) compounds. The oxidation of complexes Cp Me 3 Ce(thf) and Cp′ 3 Ce(thf) (Cp Me =C 5 H 4 Me, Cp′=C 5 H 4 SiMe 3 ), bearing monosubstituted electron‐poor cyclopentadienyl ligands, with 0.5 equivalents of 1,4‐benzoquinone or C 2 Cl 6 gave the cerium(IV) hydroquinolate complexes Cp Me 3 Ce(OC 6 H 4 O)CeCp Me 3 and Cp′ 3 Ce(OC 6 H 4 O)CeCp′ 3 , or the chloride complexes Cp Me 3 CeCl and Cp′ 3 CeCl, respectively; the iodide complex Cp′ 3 CeI was obtained from the reaction of Cp′ 3 Ce(thf) with elemental iodine. The behavior of Cp′ 3 CeCl in salt metathesis protocols employing alkali metal amides or alkyl, alkoxide, and aryloxide reagents was investigated, which gave rise to the robust and isolable cerium(IV) alkoxide Cp′ 3 Ce(O t Bu). Trivalent [Cp′ 2 CeCl] 2 was synthesized by AlMe 4 →Cl exchange utilizing Cp′ 2 Ce(AlMe 4 ) and AlMe 2 Cl. The reactivity of [Cp′ 2 CeCl] 2 towards the oxidants Ph 3 CCl, C 2 Cl 6 , 1,4‐benzoquinone, and I 2 has been assessed, and has provided useful information on Ce III /Ce IV redox deactivation pathways. In addition to X‐ray structure analysis, all the complexes were characterized by NMR, DRIFT (diffuse reflectance IR Fourier transform), and UV/Vis spectroscopy as well as elemental analysis. The tetravalent compounds were further analyzed for their magnetic susceptibility by using Evans’ method.