Off-campus UMass Amherst users: To download dissertations, please use the following link to log into our proxy server with your UMass Amherst user name and password.

Non-UMass Amherst users, please click the view more button below to purchase a copy of this dissertation from Proquest.

(Some titles may also be available free of charge in our Open Access Dissertation Collection, so please check there first.)

New indenyl group IV complexes and their use as Ziegler-Natta catalysts in the synthesis of syndiotactic polystyrene and stereoblock polypropylene

Thomas Edward Ready, University of Massachusetts Amherst


A variety of 1- and 3-substituted alkylindenes (R = Me, Et, Pr, n-Bu, t-Bu, allyl, SiMe$\sb3),$ as well as 3-methylthioindene were prepared by reacting the appropriate alkyl halide or dimethyl disulfide with indenyllithium. 3-3$\sp\prime$-Bis-(indenyl)methane was prepared by reacting two equivalents of indenyllithium with dichloromethane. 1-1$\sp\prime$-Biindene was prepared by reacting two equivalents of indenyllithium with CuBr$\sb2.$ 2-Indanone and methyl-substituted 1-indanones were prepared by reaction of the appropriate methyl-substituted benzene and the corresponding methyl-substituted acrylic acid in the presence of AlCl$\sb3.$ The indanones were converted to the corresponding methyl-substituted indenes via reaction with the methyllithium or methylmagnesium iodide, or via reduction using LiAlH$\sb4.$ Bis-(indenyl)dichlorozirconium complexes were synthesized via reactions of intermediate indenyllithium salts of the corresponding indenyl ligands with ZrCl$\sb4.$ The substituted indenes mentioned above were converted into trimethylsilyl derivatives via reactions of intermediate organolithium complexes with chlorotrimethylsilane. The corresponding titanium complexes were synthesized in excellent yield from reactions of the trimethylsilyl derivatives with TiCl$\sb4.$ Several other derivatives of IndTiCl$\sb3$, ({\bf 11}); were synthesized by various means. Hydrogenation of ({\bf 11}) using PtO$\sb2$ catalyst led to 4,5,6,7-(H$\sb4)$IndTiCl$\sb3,$ ({\bf 22}); in quantitative yield. IndTi(Me)Cl$\sb2,$ ({\bf 33}) and IndTiMe$\sb3,$ ({\bf 34}) were prepared by reacting a stoichiometric amount of methyllithium with ({\bf 11}), however, ({\bf 34}) was not isolated analytically pure. IndTiCHT, ({\bf 35}) was synthesized in 24\% yield by reacting ({\bf 11}) and cycloheptatriene in the presence of Mg shavings. The titanium complexes were evaluated as styrene polymerization catalysts in toluene solution when activated by methylaluminoxane. Activities increased in the order: $\rm CpTiCl\sb31$-(Me)IndTiCl$\sb3>1,2$-(Me$\rm\sb2)IndTiCl\sb3>1,3$-(Me$\rm\sb2)IndTiCl\sb3>2,4,7$-(Me$\rm\sb3)IndTiCl\sb3>1,4,7$-(Me$\rm\sb3)IndTiCl\sb3>1,2,3$-(Me$\rm\sb3)IndTiCl\sb3>4,5,6,7$-(Me$\rm\sb4)IndTiCl\sb3>1,2,3,4,5,6,7$-(Me$\rm\sb7)IndTiCl\sb3>1,3,4,7$-(Me$\rm\sb4)IndTiCl\sb3>1,2,4,5,6,7$-(Me$\rm\sb6)IndTiCl\sb3>Cp\sp*TiCl\sb3;$ more or less corresponding to the increased number of methyl substituents on the $\eta\sp5$-ligand in the precursor. A steep drop in styrene polymerization activity was observed in the order: 1-(Et)Ind $>$ 1-(Pr)Ind = 1-(allyl)Ind $>$ 1-(n-Bu)Ind $>$ 1-(Butenyl)Ind $>$ 1-(SiMe$\sb3)$Ind, 1-(t-Bu)Ind, corresponding to the increase in the steric bulk of the substituent in the catalyst precursor. The styrene polymerization activity of IndTiCHT was much lower than either IndTiCl$\rm\sb2CH\sb3$ or IndTiCl$\sb3.$

Subject Area


Recommended Citation

Ready, Thomas Edward, "New indenyl group IV complexes and their use as Ziegler-Natta catalysts in the synthesis of syndiotactic polystyrene and stereoblock polypropylene" (1998). Doctoral Dissertations Available from Proquest. AAI9823767.