869210-79-7Relevant academic research and scientific papers
Exploring alternative synthetic routes for the preparation of five-coordinate diamidoamine group 4 metal complexes
Morgan, Alicia R.,Kloskowski, Michael,Kalischewski, Felix,Phillips, Aaron H.,Petersen, Jeffrey L.
, p. 5383 - 5392 (2005)
Efficient synthetic routes for the preparation of electrophilic titanium and zirconium complexes featuring a tridentate diamidoamine ligand have been developed. The five-coordinate titanium dichloride complexes [(MesNCH 2CH2)2NR]TiCl2 (R = H (3), SiMe 3 (4)) are conveniently prepared from the amine elimination reactions of the triamines (MesNHCH2CH2)2NR (R = H (1), SiMe3 (2)) with Ti(NEt2)2Cl2. Treatment of Ti(NEt2)4 with 2 equiv of SiMe3Cl offers an effective method for the preparation of Ti(NEt2) 2Cl2. The corresponding five-coordinate zirconium homologues [(MesNCH2CH2)2NR]ZrCl2 (R = H (5), SiMe3 (6)) are synthesized via the toluene elimination reactions of Zr(benzyl)2Cl2(Et2O)2 with 1 and 2, respectively. The thermally unstable and photosensitive Zr(benzvl)2Cl2(Et2O)2 species may be prepared in situ from the reaction of Zr(benzyl)4 with 2 equiv of [NEt3H]Cl in diethyl ether at 0°C in the dark. The toluene elimination reaction of Hf(benzyl)4 with 1 affords the dibenzyl Hf complex [(MesNCH2CH2)2NH]Hf(benzyl) 2, 7. The X-ray structural and solution NMR data for 4, 5, 6, and 7 reveal that these electrophilic group 4 metal complexes adopt the facial structure with either a chloride or a η2-benzyl ligand trans to the central amino N atom of the tridentate diamidoamine ligand.
