Synthesis, mechanism and ethylene polymerization catalysis of Ge(iv), Sn(ii) and Zr(iv) complexes derived from substituted β-diketiminates. Issue 65 (23rd June 2016)

• Record Type: Journal Article
• Authors: Xiao, Xia; Hao, Xiaomin; Bai, Jianliang; Chao, Jianbin; Cao, Wei; Chen, Xia
• Is Part Of: RSC advances. Volume 6:Issue 65(2016)
• Page Start: 60723
• Page End: 60728
• Publication Date: 2016-06-23
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c6ra11097e
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : Unusual X-ray characterized crystalline Sn(ii ), Ge(iv ) and Zr(iv ) complexes have been prepared via a salt metathesis and elimination reaction. Abstract : Insertion of LiCH(SiMe3 )2 into the CN bond of the appropriate nitriles RCN afforded dimeric β-diketiminato lithium complexes [Li{N(SiMe3 )C(R)C(H)C(R′)N(SiMe3 )}]2 (1a, R = R′ = NMe2 ;1b, R = Bu t, R′ = o -C5 H4 N). Lithium salt1a was used as a precursor to react with SnCl2 and GeCl4, respectively, and complexes [ClSn{N(SiMe3 )C(NMe2 )C(H)C(NMe2 )N(SiMe3 )}] (2 ) and [Cl2 Ge{NC(NMe2 )C(H)C(NMe2 )N(GeCl3 )}] (3 ) were obtained in good yields. By β-diketiminato lithium1b ligand transfer, the cyclo-1, 3-diazasilane heterocyclic complex (4 ) was prepared using1b and ZrCl4 . Unexpectedly, the chelating β-diketiminato backbone in3 acts as a dianionic ligand, whereas in4, the ligand acts as a neutral cyclo-1, 3-diazasilane heterocyclic ring to coordinate with the Zr center. The X-ray structures of2–4 are presented, and reaction pathways for each complex are proposed. Upon activation with methylaluminoxane, complex4 exhibits good activity for ethylene polymerization.