Synthesis and characterization of titanium(IV) complexes containing the diphenylphosphino- and diphenylthiophosphoryl-functionalized cyclopentadienyl ligand. Crystal and molecular structure of Ti(η 5-C 5H 4PPh 2)Cl 3

Abstract

The trimethylsilyl cyclopentadiene derivative C 5H 4(SiMe 3)PPh 2 ( 1) was treated with TiCl 4 to give the air- and moisture-sensitive mono(cyclopentadienyl) compound Ti(η 5-C 5H 4PPh 2)Cl 3 ( 4). Reaction of 4 with Mg(CH 2C 6H 5) 2(THF) 2 gave Ti(η 5-C 5H 4PPh 2)(CH 2C 6H 5) 3 ( 5). Reactions of the lithium and thallium derivatives M{C 5H 4P(S)Ph 2} (M=Li ( 2), Tl ( 3)) with one equiv. of TiCl 4 afforded the mono(cyclopentadienyl) complex Ti{η 5-C 5H 4P(S)Ph 2}Cl 3 ( 6), whereas reaction with 0.5 equiv. of TiCl 4 gave the bis(cyclopentadienyl) complex Ti{η 5-C 5H 4P(S)Ph 2} 2Cl 2 ( 8). Compound 6 was also isolated as a minor product from the reaction of Ti{η 5-C 5H 4P(S)Ph 2} 2Cl 2 ( 8) with one equiv. of TiCl 4. The major product was identified as an inseparable mixture of two compounds [Ti{η 5-C 5H 4P(S)Ph 2} 2Cl 2 ·TiCl 4] n ( 7a and 7b). Reaction of Ti(η 5-C 5H 5)Cl 3 with 3 afforded the ‘mixed-ring’ bis(cyclopentadienyl) complex Ti{η 5-C 5H 4P(S)Ph 2}(η 5-C 5H 5)Cl 2 ( 9). Compounds 6–9 are very moisture-sensitive and easily decompose to form the cyclopentadiene C 5H 5P(S)Ph 2. Structural data of these complexes indicate η 5-coordination of the substituted cyclopentadienyl ligands and this coordination mode was confirmed by X-ray crystal structure analysis of compound 4.