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Homolyses of titanium-oxygen bonds: ...

Huang, Kuo-Wei.

Homolyses of titanium-oxygen bonds: A novel strategy for generating titanium(III) complexes.

Record Type:	Electronic resources : Monograph/item
Title/Author:	Homolyses of titanium-oxygen bonds: A novel strategy for generating titanium(III) complexes.
Author:	Huang, Kuo-Wei.
Description:	260 p.
Notes:	Adviser: Robert M. Waymouth.
Notes:	Source: Dissertation Abstracts International, Volume: 65-11, Section: B, page: 5727.
Contained By:	Dissertation Abstracts International65-11B.
Subject:	Chemistry, Organic.
Online resource:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3153054
ISBN:	0496135007

Homolyses of titanium-oxygen bonds: A novel strategy for generating titanium(III) complexes.
Huang, Kuo-Wei.

Homolyses of titanium-oxygen bonds: A novel strategy for generating titanium(III) complexes. - 260 p.

Adviser: Robert M. Waymouth.

Thesis (Ph.D.)--Stanford University, 2005.

DFT and experimental studies reveal that the strength of the Ti-O bond decreases with the number of cyclopentadienyl groups on titanium or added donor ligands. The calculated Ti-O bond strength of CpTiCl2(TEMPO) is 43 kcal/mol, whereas that of Cp2TiCl(TEMPO) is 17 kcal/mol. A mono-Cp pendant dimethylamino complex, CpNTiCl2(TEMPO), has a Ti-O bond strength of 26 kcal/mol. The sensitivity of these Ti-O bonds to ancillary ligands implies that the influence of ancillary ligands, particularly cyclopentadienyl ligands, on Ti-X bond strengths is larger than anticipated, and the assumption of transferability of Ti-X bond strengths among different ligand environments is inappropriate.

ISBN: 0496135007Subjects--Topical Terms:

193634
Chemistry, Organic.

Homolyses of titanium-oxygen bonds: A novel strategy for generating titanium(III) complexes.
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100 0 $a Huang, Kuo-Wei. $3 237427
245 1 0 $a Homolyses of titanium-oxygen bonds: A novel strategy for generating titanium(III) complexes.
300 $a 260 p.
500 $a Adviser: Robert M. Waymouth.
500 $a Source: Dissertation Abstracts International, Volume: 65-11, Section: B, page: 5727.
502 $a Thesis (Ph.D.)--Stanford University, 2005.
520 # $a DFT and experimental studies reveal that the strength of the Ti-O bond decreases with the number of cyclopentadienyl groups on titanium or added donor ligands. The calculated Ti-O bond strength of CpTiCl2(TEMPO) is 43 kcal/mol, whereas that of Cp2TiCl(TEMPO) is 17 kcal/mol. A mono-Cp pendant dimethylamino complex, CpNTiCl2(TEMPO), has a Ti-O bond strength of 26 kcal/mol. The sensitivity of these Ti-O bonds to ancillary ligands implies that the influence of ancillary ligands, particularly cyclopentadienyl ligands, on Ti-X bond strengths is larger than anticipated, and the assumption of transferability of Ti-X bond strengths among different ligand environments is inappropriate.
520 # $a Syndiotactic polystyrene (sPS) is a semi-crystalline thermoplastic with many desirable properties. However, sPS is brittle and difficult to process because of its high Tg and Tm. An approach to improve sPS is to incorporate a small amount of comonomer. Attempts to prepare ethylene/sPS copolymers using CpTiCl3/MAO resulted in polyethylene, sPS homopolymers, and random styrene/ethylene copolymers which lack the desirable properties of sPS. DFT calculations illuminate the roles of Ti(IV) and Ti(III) cations in ethylene and styrene polymerizations.
520 # $a The homolysis of weak metal ligand bonds derived from stable nitroxyl radicals provides a novel method for generating odd-electron organometallic reactive intermediates.
520 # $a Thermolysis of the titanocene TEMPO complexes in the presence of epoxides leads to the Cp2Ti(III)Cl-mediated ring-opening of the epoxide followed by trapping by the nitroxyl radical. Ring-opening of indene oxide is highly diastereoselective, leading to trans-1-(2,2,6,6-tetramethylpiperidine)-oxy-2-hydroxyindane, upon hydrolysis. The adduct formed by the reaction of Cp2TiCl(TEMPO) and styrene oxide is an active initiator for the controlled radical polymerizations of styrene.
520 # $a We have prepared a series of novel titanium nitroxide complexes. The titanium-oxygen bond strengths are sensitive to the ancillary ligands and the nitroxide. Direct measurements of the rate of Ti-O bond homolysis in titanocene nitroxide complexes were conducted by nitroxide exchange experiments, giving an upper-limit of the Ti-O bond dissociation energies of 25 kcal/mole, which constitutes the weakest Ti-O bonds known for neutral complexes.
590 $a School code: 0212.
650 # 0 $a Chemistry, Organic. $3 193634
650 # 0 $a Chemistry, Inorganic. $3 197298
690 $a 0488
690 $a 0490
710 0 # $a Stanford University. $3 212607
773 0 # $g 65-11B. $t Dissertation Abstracts International
790 $a 0212
790 1 0 $a Waymouth, Robert M., $e advisor
791 $a Ph.D.
792 $a 2005
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