Synthesis and structures of dinuclear low-coordinate lithium and zirconium(iv) complexes derived from the diamido ligands 1,3-(CH2N̄C6H3R12)2C6H4(R1= Me or Pri)
Daniele, Stéphane; Hitchcock, Peter B.; Lappert, Michael F.; Nile, Terence A.; Zdanski, Colette M.; Daniele Stéphane; The Chemistry Laboratory, University of Sussex; Hitchcock Peter B.; The Chemistry Laboratory, University of Sussex; Lappert Michael F.; The Chemistry Laboratory, University of Sussex; Nile Terence A.; Department of Chemistry, UNC Greensboro; Zdanski Colette M.; Department of Chemistry, UNC Greensboro
Журнал:
Journal of the Chemical Society, Dalton Transactions
Дата:
2002
Аннотация:
Treatment of 1,3-bis(bromomethyl)benzene with two equivalents of the appropriate compound Li[N(H)C6H3R<sup>1</sup>2-2,6] yielded the diamines 1,3-[CH2N(H)C6H3R<sup>1</sup>2-2,6]2C6H4 1 [R<sup>1</sup> = Me, abbreviated as H2(D)] or 2 [R = Pr<sup>i</sup>, abbreviated as H2(Dâ ²)]. The crystalline complex [Li2(Dâ ²)]2 3 was obtained from 2 and 2 LiBu<sup>n</sup>; the analogue from 1 and 2 LiBu<sup>n</sup> was an incompletely characterised oil. The binuclear, crystalline zirconium(iv) amides [{Zr(NMe2)3}2(μ-Dâ ²)] 4, its D analogue 5 and [{Zr(NMe2)2}2(μ-D)2] 6 were prepared from [{Zr(NMe2)3(μ-NMe2)}2] and H2(Dâ ²) [or 2 H2(Dâ ²)], H2(D) and 2 H2(D), respectively. The single crystal X-ray molecular structures of complexes 3 and 4 have been elucidated. That of 3 comprises a sixteen-membered, twisted macrocyclic .ub1s;LiNC5NLiNC5N.ub1e; core with each of the two-coordinate lithium atoms part of the .ub1s;LiNLiN.ub1e; rhombus. The four-coordinate zirconium atoms in 4 are in an only slightly distorted tetrahedral environment, with the two Zr(NMe2)3 units arranged trans to one another across the central aromatic ring. None of 4â 6, with MAO, showed catalytic activity for ethylene polymerisation under ambient conditions.
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