論文

査読有り
2019年

Neutral and Anionic Monomeric Zirconium Imides Prepared via Selective C=N Bond Cleavage of a Multidentate and Sterically Demanding β-Diketiminato Ligand

Chemistry - An Asian Journal
  • Takashi Kurogi
  • ,
  • Jiaxiang Chu
  • ,
  • Yaofeng Chen
  • ,
  • Daniel J. Mindiola

14
15
開始ページ
2629
終了ページ
2638
記述言語
掲載種別
研究論文(学術雑誌)
DOI
10.1002/asia.201900451

© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim A sterically encumbering multidentate β-diketiminato ligand, tBuL2 (tBuL2=[ArNC(tBu)CHC(tBu)NCH2CH2N(Me)CH2CH2NMe2]−, Ar=2,6-iPr2C6H3), is reported in this study along with its coordination chemistry to zirconium(IV). Using the lithio salt of this ligand, Li(tBuL2) (4), the zirconium(IV) precursor (tBuL2)ZrCl3 (6) could be readily prepared in 85 % yield and structurally characterized. Reduction of 6 with 2 equiv of KC8 resulted in formation of the terminal and mononuclear zirconium imide-chloride [C(tBu)CHC(tBu)NCH2CH2N(Me)CH2CH2NMe2]Zr(=NAr)(Cl) (7) as the result of reductive C=N cleavage of the imino fragment in the multidentate ligand tBuL2 by an elusive ZrII species (tBuL2)ZrCl (A). The azabutadienyl ligand in 7 can be further reduced by 2 e− with KC8 to afford the anionic imide [K(THF)2]{[CH(tBu)CHC(tBu)NCH2CH2N(Me)CH2CH2N(Me)CH2]Zr=NAr} (8-2THF) in 42 % isolated yield. Complex 8-2THF results from the oxidative addition of an amine C−H bond followed by migration to the vinylic group of the formal [C(tBu)CHC(tBu)NCH2CH2N(Me)CH2CH2NMe2]− ligand in 7. All halides in 6 can be replaced with azides to afford (tBuL2)Zr(N3)3 (9) which was structurally characterized, and reduction with two equiv of KC8 also results in C=N bond cleavage of tBuL2 to form [C(tBu)CHC(tBu)NCH2CH2N(Me)CH2CH2NMe2]Zr(=NAr)(N3) (10), instead of the expected azide disproportionation to N3− and N2. Solid-state single crystal structural studies confirm the formation of mononuclear and terminal zirconium imido groups in 7, 8-Et2O, and 10 with Zr=NAr distances being 1.8776(10), 1.9505(15), and 1.881(3) Å, respectively.

リンク情報
DOI
https://doi.org/10.1002/asia.201900451
PubMed
https://www.ncbi.nlm.nih.gov/pubmed/31233290
Scopus
https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85068147483&origin=inward
Scopus Citedby
https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85068147483&origin=inward

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