Date of Award

1998

Publication Type

Doctoral Thesis

Degree Name

Ph.D.

Department

Chemistry and Biochemistry

Keywords

Chemistry, Inorganic.

Supervisor

Stephan, Doug,

Rights

info:eu-repo/semantics/openAccess

Abstract

The thiolate complexes, CpTi(OC6H3-2,6- i-Pr2)(SR)Cl (R = Et, t-Bu, CH2 Ph, Ph), were prepared. Reaction of CPTi(OC6H3-2,6- i-Pr2(Me)Cl with t butylthiol in the presence of base afforded the species CpTi(OC6H3-2,6- i-Pr2(Me)(SCMe3). The analogous species CPTi(OC 6H3-2,6-i-Pr2) (Me) (SCH2Me) is unstable, liberating methane and yielding the dimeric product of C-H bond activation, [CpTi(OC6H3-2,6- i-Pr2)(m-SCHMe)]2. In a related thermolysis of CpTi(OC6H3-2,6-i-Pr2)(SBn) 2, the dimer species [CpTi(m-S)(OC6H3-2,6- i-Pr2)]2 and (PhCH2)2S are obtained. Kinetic studies of the C-S bond thermolysis reaction are consistent with an intramolecular process proceeding via a terminal sulphide intermediate and rapid dimerization (k = 2.8 x 10-6 s -1). The LiCL adduct of a terminal sulphide species Cp*Ti(OC 6H3-2,6-i-Pr2) (m-S)(m-Cl)Li(THF) 2 as isolated from the reaction of Cp*Ti(OC6H3-2- i-Pr2) with Li2S. Titanium-sulphide chemistry was extended, describing the syntheses, structures and chemistry of monocyclopentadienyl-titanium aryloxide sulphide complexes. Reduction of CPTi(OC6H3-2,6-i-Pr 2)Cl2 or CpTi(OC6H3-2,6-i-Pr 2)(SPh)Cl with nBuLi affords the Ti(III) compounds [CpTi(OC 6H3-2,6-i-Pr2)(m-Cl)]2 and [CpTi(OC6H3-2,6-i-Pr2)(M-SPh)] 2 respectively. Oxidation of these Ti(III) dimers with S8 yields [CpTi(OC6H3-2,6-i-Pr2)] 2(mS)(m-S2). Reaction of the sulphide bridged dieter [CpTi(OC 6H3-2,6-i-Pr2(m-S)]2 with sulfur provides an alternative route to [CpTi(OC6H3-2,6- i-Pr2)]2(m-S)(m-S2). The conversion of [CpTi(OC6H3-2,6-i-Pr2)(m-S)] 2 to [CpTi(OC6H3-2,6-i-Pr 2)]2(m-S)(m-S2) is reversible as reaction of [CpTi(OC 6H3-2,6-i-Pr2)]2(m-S)(m-S 2) with PPh3 yields SPPh3 and [CpTi(OC6H 3-2,6-i-Pr2)(m-S)]2. Isolation of a monosulphide bridged species [CpTi(OC6H3-2,6- i-Pr2)2]2(m-S) is achieved via reaction of [CpTi(OC6H3-2,6-i-Pr)2Cl with Li2S. Nucleophilic substitution reactions employing CpTi(OC6H 3-2,6-i-Pr2)Cl2, base and the appropriate reagent offer facile access to the series of compounds, CpTi(OC 6H3-2,6-i-Pr2)3, CpTi(OC 6H3-2,6-i-Pr2)2(NH(C 6H3-2,6-Pr2)), CpTi(OC6H3-2,6- i-Pr2)2(SPh) and CpTi(OC6H 3-2,6-i-Pr)2PHPh. Crystallographic studies of these complexes suggest that steric congestion associated with the three bulky ancillary ligands rather than metal-ligand p-interactions dictates the observed geometries. Several of the aryloxide complexes were monitored for their potential to act as olefin polymerisation catalysts. It was found that monocydopentadienyl complexes became better catalysts with the addition of one or two OR* substituents.Dept. of Chemistry and Biochemistry. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1998 .F57. Source: Dissertation Abstracts International, Volume: 61-09, Section: B, page: 4713. Adviser: Doug Stephan. Thesis (Ph.D.)--University of Windsor (Canada), 1998.

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