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 ...