Synthesis and characterization of titanium(IV) complexes containing the diphenylphosphino- and diphenylthiophosphoryl-functionalized cyclopentadienylligand. Crystal and molecular structure of Ti(eta(5)-C5H4PPh2)Cl-3

The trimethysilyl cyclopentadiene derivative C5H4(SiMe3)PPh2 (1) was treate d with TiCl4 to give the air- and moisture-sensitive mono(cyclopentadienyl) compound Ti(eta(5)-C5H4PPh2)Cl-3 (4). Reaction of 4 with Mg(CH2C6H5)(2)(TH F)(2) gave Ti(eta(5)C(5)H(4)PPh(2))(CH2C6H5)(3) (5). Reactions of the lithi um and thallium derivatives M{C5H4P(S)Ph-2} (M = Li (2), Tl (3)) with one e quiv. of TiCl4 afforded the mono(cyclopentadienyl) complex Ti{eta(5)-C5H4P( S)Ph-2}Cl-3 (6), whereas reaction with 0.5 equiv. of TiCl4 gave the bis(cyc lopentadienyl) complex Ti{eta(5)-C5H4P(S)Ph-2}(2)Cl-2 (8). Compound 6 was a lso isolated as a minor product from the reaction of Ti{eta(5)-C5H4P(S)Ph-2 }(2)Cl-2 (8) with one equiv. of TiCl4. The major product was identified as an inseparable mixture of two compounds [Ti{eta(5)-C5H4P(S)Ph-2}(2)Cl-2. Ti Cl4](n) (7a and 7b). Reaction of Ti(eta(5)-C5H5)Cl-3 with 3 afforded the 'm ixed-ring' bis(cyclopentadienyl) complex Ti{eta(5)-C5H4P(S)Ph-2}(eta(5)-C5H 5)Cl-2 (9). Compounds 6-9 are very moisture-sensitive and easily decompose to form the cyclopentadiene C5H5P(S)Ph-2. structural data of these complexe s indicate eta(5)-coordination of the substituted cyclopentadienyl ligands and this coordination mode was confirmed by X-ray crystal structure analysi s of compound 4. (C) 2000 Elsevier Science S.A. All rights reserved.