Titanium and Zirconium Complexes Containing a Novel Dianionic Trifunctional Amido Ligand

Abstract

Abstract The novel tridentate diamidoamine ligands [RC( 2 C 5 H 4 N)(CH 2 NSiMe 3 ) 2 ) 2− (R = H, CH 3 ) have been synthesized and coordinated to Ti IV giving the pentacoordinate complexes [MX 2 (RC(2‐C 5 H 4 N)(CH 2 NSiMe 3 ) 2 }] (M = Ti, Zr; X = Cl, Br). The crystal structure analysis of [TiBr 2 {HC(2‐C 5 H 4 N)(CH 2 ) 2 }] (M = Ti, Zr; X = Cl, Br). The crystal structure analysis of [TiBr 2 {HC(2‐C 5 H 4 N)(CH 2 NSiMe 3 ))] ( 10b ) confirmed the involvement of the pyridyl function in the coordination to the meta centre occupying an apical position in the trigonal bipyramidal ligand polyhedron. alkylation of [TiCl 2 {H 3 CC(2‐C 5 H 4 N)(CH 2 NSiMe 3 ) 2 )] ( 12a ) with one or two molar equivalents of [RMgCl](R = PhCH 2 , Me 3 SiC 2 ) yielded the mono‐ and dialkyl complexes [TiClR{H 3 CC(2‐C 5 H 4 N)(CH 2 NSiMe 3 ) 2 )] and [TiR 2 (H 3 CC(2‐C 5 H 4 N)(CH 2 NSiMe 3 ) 2 )] and [TiR 2 (H 3 CC(2‐C 5 H 4 N)(CH 2 NSiMe 3 ) 2 }] in good yields. Depending on the steric demand of the alkyl group coordination or decoordination of the pyridyl group leads to four‐ or five‐coordinate species. A crystal structure analysis of the pentacoordinate complex [TiCl(CH 2 SiMe 3 ){H 3 CC(2‐C 5 H 4 N)(CH 2 NSiMe 3 ) 2 }] ( 16 ) was carried out.