Synthesis of Trichloro(η5-alkenyltetramethylcyclopentadienyl)titanium(IV) Complexes and Their Activity in Styrene Polymerization

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Title:Synthesis of Trichloro(η5-alkenyltetramethylcyclopentadienyl)titanium(IV) Complexes and Their Activity in Styrene Polymerization
Creators:
Zemánek, Jaroslav
Fröhlichová, Lenka
Šindelář, Pavel
Štěpnička, Petr
Císařová, Ivana
Varga, Vojtech
Horáček, Michal
Mach, Karel
Journal or Publication Title:
Collection of Czechoslovak Chemical Communications, 66, 9, pp. 1359-1374
Uncontrolled Keywords:Substituted cyclopentadienyl ligands, Titanium, Pendant alkenyl groups, Trichloro(cyclopentadienyl)titanium complexes, Half-sandwich complexes, Cationic polymerizations, Styrene, Syndiotactic polystyrene, Crystal structure

Abstract

Fully substituted trichloro(η<sup>5</sup>-cyclopentadienyl)titanium(IV) complexes with pendant alkenyl groups, [TiCl<sub>3</sub>(η<sup>5</sup>-C<sub>5</sub>Me<sub>4</sub>R)] (R = CH(Me)CH=CH<sub>2</sub> (<strong>3a</strong>), (CH<sub>2</sub>)<sub>2</sub>CH=CH<sub>2</sub> (<strong>3b</strong>), and (CH<sub>2</sub>)<sub>3</sub>CH=CH<sub>2</sub> (<strong>3c</strong>)), were synthesized by the reaction of the corresponding trimethylsilyl or trimethylstannyl substituted cyclopentadienes C<sub>5</sub>Me<sub>4</sub>R(EMe<sub>3</sub>), where E = Si or Sn, with TiCl<sub>4</sub>. In all cases, the pendant double bonds did not exhibit any interaction with the titanium atoms as indicated by <sup>1</sup>H, <sup>13</sup>C NMR or IR spectra as well as by the solid-state structure of <strong>3c</strong>. The catalytic systems prepared by mixing complexes <strong>3a</strong>-<strong>3c</strong>, [TiCl<sub>3</sub>(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)], [TiCl<sub>3</sub>(η<sup>5</sup>-C<sub>5</sub>H<sub>5</sub>)], and similar complexes with R = butyl (<strong>4</strong>), phenyl (<strong>5</strong>), 4-fluorophenyl (<strong>6</strong>) with methylalumoxane (MAO) at the molar ratio Al/Ti = 500 catalyzed polymerization of styrene to syndiotactic polystyrene. Their polymerization activities increase in the order: [TiCl<sub>3</sub>(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)] &lt; <strong>3a</strong> &lt; <strong>3b</strong> &lt; <strong>3c</strong> &lt; <strong>4</strong> &lt; <strong>5</strong> &lt; <strong>6</strong> &lt; [TiCl<sub>3</sub>(η<sup>5</sup>-C<sub>5</sub>H<sub>5</sub>)], while the molecular weights (<i>M</i><sub>w</sub>) of syndiotactic polystyrene grow in the order: [TiCl<sub>3</sub>(η<sup>5</sup>-C<sub>5</sub>H<sub>5</sub>)] &lt; <strong>3a</strong> &lt;<strong>3b</strong> &lt; <strong>4</strong> ≈ <strong>6</strong> &lt; [TiCl<sub>3</sub>(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)] &lt; <strong>3c</strong> ≈ <strong>5</strong> (maximum <i>M</i><sub>w</sub> <i>ca</i> 3.0 · 10<sup>5</sup>). A comparison of the results for the catalytic systems based on <strong>4</strong> with those derived from <strong>3a</strong>-<strong>3c</strong> points to a rather weak competition of the pendant double bonds with monomer for a cationic Ti(III) catalytic centre. <p>

Title:Synthesis of Trichloro(η5-alkenyltetramethylcyclopentadienyl)titanium(IV) Complexes and Their Activity in Styrene Polymerization
Creators:
Zemánek, Jaroslav
Fröhlichová, Lenka
Šindelář, Pavel
Štěpnička, Petr
Císařová, Ivana
Varga, Vojtech
Horáček, Michal
Mach, Karel
Uncontrolled Keywords:Substituted cyclopentadienyl ligands, Titanium, Pendant alkenyl groups, Trichloro(cyclopentadienyl)titanium complexes, Half-sandwich complexes, Cationic polymerizations, Styrene, Syndiotactic polystyrene, Crystal structure
Divisions:Life and Chemical Sciences > Institute of Organic Chemistry and Biochemistry > Collection of Czechoslovak Chemical Communications
Journal or Publication Title:Collection of Czechoslovak Chemical Communications
Volume:66
Number:9
Page Range:pp. 1359-1374
ISSN:0010-0765
E-ISSN:1212-6950
Publisher:Institute of Organic Chemistry and Biochemistry
Related URLs:
URLURL Type
http://dx.doi.org/10.1135/cccc20011359UNSPECIFIED
ID Code:1862
Item Type:Article
Deposited On:06 Feb 2009 17:13
Last Modified:06 Feb 2009 16:13

Citation

Zemánek, Jaroslav; Fröhlichová, Lenka; Šindelář, Pavel; Štěpnička, Petr; Císařová, Ivana; Varga, Vojtech; Horáček, Michal; Mach, Karel (2001) Synthesis of Trichloro(η5-alkenyltetramethylcyclopentadienyl)titanium(IV) Complexes and Their Activity in Styrene Polymerization. Collection of Czechoslovak Chemical Communications, 66 (9). pp. 1359-1374. ISSN 0010-0765

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