Synthesis and structures of o-phenylene-bridged Cp/phosphinoamide titanium complexes

Addition of R′2PCl to anilines substituted with di- or trimethylcyclopentadienyl unit at ortho-position affords ortho-phenylene-bridged Me2Cp or Me3Cp/phosophinoamide ligands, 2-(RMe2C5H2)C6H4NHPR′2 (R = Me or H; R′ = Ph, iPr, or Cyclohexyl). Successive addition of Ti(NMe2)4 and Me2SiCl2 to the ligands affords the desired dichlorotitanium complexes, [2-(η5-RMe2C5H)C6H4NPR′ 2− κ2N,P]TiCl2 (R = H, R′ = Ph, 9; R = Me, R′ = Ph, 10; R = H, R′ = iPr, 11; R = Me, R′ = iPr, 12; R = H, R′ = Cy, 13; R = Me, R′ = Cy, 14). By using Zr(NMe2)4 instead of Ti(NMe2)4, a zirconium complex, [2-(η5-Me3C5H)C6H4NP(iPr)2−κ2N,P]ZrCl2 (15) is prepared. Molecular structures of 10, 14 and [2-(η5-Me2C5H2)C6H4NPPh2− κN]Ti(NMe2)2 (16) were determined. The metric parameters determined on the X-ray crystallographic studies and the chemical shifts of the 31P NMR signal indicate that the phosphorous atom coordinates to the titanium in the dichloro-complexes 9–15. The titanium and zirconium complexes show negligible activity in ethylene and ethylene/1-hexene (co)polymerization when activated with MAO or iBu3Al/[Ph3C][B(C6F5)4].

o-Phenylene-bridged Me2Cp or Me3Cp/phosphinoamide titanium and zirconium complexes were prepared and the structures of some complexes were determined by X-ray crystallography. They show negligible activity in ethylene polymerization.Figure optionsDownload as PowerPoint slide