874750-70-6Relevant academic research and scientific papers
Synthesis and structures of some sterically hindered zinc complexes containing 6-membered and rings
Farwell, James D.,Hitchcock, Peter B.,Lappert, Michael F.,Luinstra, Gerrit A.,Protchenko, Andrey V.,Wei, Xue-Hong
, p. 1861 - 1869 (2008)
Zinc β-diketiminates containing the N,N′-chelating ligand [{N(SiMe3)C(Ph)}2CH]- (≡LL-) [Zn(LL)(μ-Cl)]2 (1) and [ZnEt(LL)thf] (2) were prepared from 2ZnCl2 + [Li(LL)]2 and ZnEt2 + H(LL), respectively. The new phenols 2-(N-R-piperazinyl-N′-methyl)-4,6-di-tert-butylphenol [R = Ph (3a), Me (3b)] and 2,2-[μ-N,N′-piperazindiyldimethyl]-bis(4,6-di-tert-butylphenol) (4) were obtained from 2,4-tBu2C6H3OH, (CH2O)n and the appropriate piperazine. Zinc phenoxides 5, 7 and 8 were derived from 2ZnEt2 with 2(3a), 2(3b) and 4, respectively. Controlled methanolysis of 5 furnished the bis(phenoxo)zinc compound Zn[OC6H2tBu2-2,4-{CH2N(CH2CH2)2NPh}-6]2 (6). The X-ray structures of the crystalline zinc compounds 1, 2, 5, 6, 7 and 8, are presented; each of 5-8 contains two {A figure is presented} six-membered rings. The centrosymmetric molecule 1 has a rhomboidal (ZnCl)2 core with exceptionally different Zn-Cl and Zn-Cl′ bond lengths of 2.248(1) and 2.509(1) A?, respectively. None of 1, 2 or 5-8 was an effective catalyst for the copolymerisation of an oxirane and CO2.
Zinc complexes of piperazinyl-derived aminephenolate ligands: Synthesis, characterization and ring-opening polymerization activity
Ikpo, Nduka,Saunders, Lisa N.,Walsh, Jillian L.,Smith, Jennifer M. B.,Dawe, Louise N.,Kerton, Francesca M.
experimental part, p. 5347 - 5359 (2012/02/05)
A series of zinc complexes was prepared from 4,6-disubstituted (R,R′) o-[(4-methyl-1-piperazinyl)methyl]phenols ([ONNR′,R]H) and characterized by elemental analysis, 1H and 13C{ 1H} NMR spectroscopy, and X-ray crystallography. Reaction of these products with diethylzinc gave Zn[ONNtBu,tBu]2 (1) as a monometallic complex and {[μ-ONNR′,R]ZnEt}2 [R′ = Me, R = tBu, (2); R′ = R = tBu (3); R′ = R = tAm (4)] bimetallic species that have distorted tetrahedral environments about the Zn centres. Reaction of 3 and 4 with alcohols gave {[ONNtAm,tAm]Zn(μ- OR″)}2 [R″ = Bn (5); R″ = Et (6)] bimetallic species in which the Zn centres are bridged by benzyl alkoxide and ethoxide groups, respectively. A morpholinyl derived ligand was also synthesized and characterized (L4H), and its 1:1 stoichiometric reaction with ZnEt2 resulted in complex 7, {[μ-ONOtBu,tBu]ZnEt}2. The reactivity of complexes 2-7 in the ring-opening polymerization of rac-lactide (LA) and Iμ-caprolactone (Iμ-CL) was studied. Reactions of carbon dioxide with cyclohexene oxide in the presence of 6 or 7/ROH (R = Bn, Et) afforded cyclohexene carbonate.
Synthesis, characterization and catalytic activity of magnesium and zinc aminophenoxide complexes: Catalysts for ring-opening polymerization of l-lactide
Chuang, Hui-Ju,Weng, Shi-Feng,Chang, Chia-Chih,Lin, Chu-Chieh,Chen, Hsuan-Ying
experimental part, p. 9601 - 9607 (2011/11/13)
A series of novel magnesium and zinc aminophenoxide complexes were successfully synthesized and one zinc complex was characterized by X-ray crystallography. They were also investigated as initiators for the ring opening polymerization of l-lactide. The co
