Synthesis And Characterization Of Guanidinate Titanium Complexes And Their Catalytic Behavior For Polymerization

Seven guanidinate titanium complexes were first synthesized and well characterized. Three complexes of them were characterized by X-ray diffraction structural analysis. The catalytic behaviors of some guanidinate titanium complex were tested.1. Reaction of Pr'N=C=NPri with lithium diisopropylamide in THF afforded the guanidinate lithium (i-PrN)C[NPr'2](N/-Pr)}Li}2(THF)2 (1).2. CyN=C=NCy reacted with lithium 2,6-diisopropylaniline in 1:1 molar ratio to produce the asymmetric guanidinate lithium [Cy(H)NC(NCy)(NC6H5-2,6-Pr')Li(THF)]2 (2).3. Guanidinate lithium [Pr2iNC(NCy)2]Li, [Ph2NC(NCy)2]Li, [Ph2NCCNPr]Li, [(C5H10)NC(NCy)2]Li, [(C5H10)NC(NPri)2]Li, (Cy = cyclohexyl, Prj = isopropyl, Ph = phenyl) formed in situ reacted with TiCl4(THF)2 in 2:1 molar ratio to produce the guanidinate titanium chloride [Pr2iNC(NR)2]2TiCl2 [(R = Cy) (3)], [Ph2NC(NR)2]2TiCl2 [R = Cy (4); R = Prj (6)], [(C5Hi0)NC(NR)2]2TiCl2 [R = Cy (6);R = Prj (7)] in good yield. Their structure was characterized by elemental analyses, !H NMR, IR. Complexes 3 and 7 were characterized by X-ray crystal structure determination.4. Reaction of [Pr2iNC(NCy)2]2TiCl2 with lithium diisopropylamide in THF afforded the unexpected [Pr2'NC(NCy)2]Ti(OBun)2 (8), which was formed by the cleavage of the carbon-oxygen bond of THF. Complex 8 was characterized by elemental analysis, *H NMR. IR, and X-ray crystal structure determination.5. Guanidinate lithium 2 formed in situ reacted with TiCl4(THF)2 in 1:1 molar ratio to produce complex [Cy(H)NC(NCy)(NC6H5-2,6-Pr1)]2TiCl2 (9). Complex 9 was characterized by elemental analysis, 'H NMR, IR.6. CpNa (Cp = C5Hs) reacted with TiCl4(THF)2 in 1:1 molar ratio to produce the cyclopentadienyl titanium chloride CpTiChfTHF), then reacted with guanidinate lithium[Pr2'NC(NCy)2]Li(Cy = cyclohexyl) formed in situ in 1:1 molar ratio to produce the cyclopentadienyl-guanidinate titanium chloride [Pr2'NC(NR)2]CpTiCl2 (10). Complex 10 was characterized by elemental analyses, 'H NMR, IR.7. [2,4-BuVl-OH-C6H2-C=N-(4'-R-r-OH-C6H4)] (R = Bu1 , H ) [ONO] reacted with n-BuLi in 1:1 molar ratio to produce lithium salt, and then reacted with TiCl4(THF)2 in 1:1 molar ratio to produce [ONO]TiCl2(R = Bu111, R = H 12).8. The catalytic activities of complexes 3-7 in the presence of MMAO for the styrene polymerization were tested. The preliminary results indicated that the polystyrenes obtained are syndiotactic polymers.