Collect. Czech. Chem. Commun. 1999, 64, 61-72

Syntheses and Crystal Structures of Dichlorobis[tetramethyl(phenyl)cyclopentadienyl]titanium(IV) and Chlorobis[tetramethyl(phenyl)cyclopentadienyl]titanium(III)

Michal Horáčeka, Miroslav Polášeka, Volkmar Kupferb, Ulf Thewaltb and Karel Macha,*

a J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, 182 23 Prague 8, Czech Republic
b Sektion für Röntgen- und Elektronenbeugung, Universität Ulm, 89069 Ulm, Germany


Dichlorobis[η5-tetramethyl(phenyl)cyclopentadienyl]titanium(IV) (1) and chlorobis[η5-tetramethyl- (phenyl)cyclopentadienyl]titanium(III) (2) were prepared by the generally known procedures. The X-ray crystal structures of 1 and 2 showed nearly identical Ti-CE (CE - centroid of the cyclopentadienyl ring) and Ti-Cl distances, the CE-Ti-CE angles and dihedral angles between least-squares planes of the cyclopentadienyl rings to those in [(C5Me5)2TiCl2] and [(C5Me5)2TiCl], respectively. ESR spectra of 2 in 2-methyltetrahydrofuran (MTHF) solutions and glasses revealed that 2 coordinates MTHF to give [(C5Me4Ph)2Ti(Cl)(MTHF)] (2a). The formation of 2a in MTHF solution is completed by lowering temperature to 205 K. A comparison with the known data gives the following order of affinity of [(C5Me4R)2TiCl] towards MTHF: Ph > SiMe3 > H > Me.

Keywords: Titanium; Metallocenes; Titanocenes; Sandwich complexes; Tetramethyl(phenylcyclopentadienyl ligand; Crystal structures; Electronic effect.