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Structural diversity in substituted aminosilyl‐aminopyridinate metal (Zr or Fe) complexes: Synthesis, structures, and ethylene polymerization
Author(s) -
Duan XinE,
Zhang XiaoXia,
Liu Tian,
Bai ShengDi,
Tong Hongbo,
Chao JianBin,
Sun WenHua
Publication year - 2021
Publication title -
applied organometallic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.53
H-Index - 71
eISSN - 1099-0739
pISSN - 0268-2605
DOI - 10.1002/aoc.6240
Subject(s) - chemistry , trigonal bipyramidal molecular geometry , ligand (biochemistry) , zirconium , crystallography , pentagonal bipyramidal molecular geometry , ethylene , stereochemistry , metal , coordination geometry , medicinal chemistry , crystal structure , catalysis , molecule , inorganic chemistry , hydrogen bond , biochemistry , receptor , organic chemistry
Seven examples of chlorozirconium N ‐[( N , N ‐dimethylamino)dimethylsilyl]‐2‐pyridylaminates, mononuclear monoligand Zr[(RC 5 H 4 N)NSiMe 2 NMe 2 ]Cl 3 LiCl(Et 2 O) 2 ( R = 4‐Me, Zr1 ; R = 5‐Me, Zr2 ; R = 5‐Cl, Zr3 ), chloro‐bridged dinuclear diligand [Zr{(RC 5 H 4 N)NSiMe 2 NMe 2 }Cl 3 ] 2 ( R = 5‐Cl, Zr4 ; R = 4‐Cl, Zr5 ), and mononuclear triligand Zr[(RC 5 H 4 N)NSiMe 2 NMe 2 ] 3 Cl ( R = 6‐Me, Zr6 ; R = H, Zr7 ), have been prepared by the individual reactions of zirconium tetrachloride with the corresponding lithium N ‐[( N , N ‐dimethylamino)dimethylsilyl]‐2‐pyridylaminates of (RC 5 H 4 N)NHSiMe 2 NMe 2 ( R = 4‐Me, 1a ; 5‐Me, 1b ; 5‐Cl, 1c ; 4‐Cl, 1d ; 6‐Me, 1e ; H, 1f ), respectively. Besides seven coordination around zirconium core, Zr1 – Zr5 adopt a distorted pentagonal bipyramid geometry with the ligand acting as a monoanionic η 2 :η 1 ‐tridentate fashion; Zr6 – Zr7 present capped trigonal prism geometry with the ligand as η 2 ‐coordination with a pendant N (CH 3 ) 2 free. Extensively, the reactions of FeCl 2 with lithiated (RC 5 H 4 N)NHSiMe 2 NMe 2 ( R = 4‐Me, 1a ; 5‐Cl, 1c ; 6‐Me, 1e ) afford the corresponding dimeric complexes ( R = 4‐Me, Fe1 ; 5‐Cl, Fe2 ; 6‐Me, Fe3 ), in which Fe1 and Fe2 exhibit C 2 symmetry with each iron unit as a distorted trigonal bipyramidal geometry, while Fe3 specially possesses a centrosymmetric hour‐glass‐shaped core with each iron center as a distorted tetrahedral geometry. Upon activation with methylaluminoxane (MAO), zirconium complexes exhibit moderate to good activities toward ethylene polymerization and produce the polyethylenes with high molecular weight and broad dispersity.