Syntheses and Crystal Structures of Dichl Orobis[Tetra-Methyl(Phenyl)Cyclopentadienyl]Titanium(IV) and Chlorobis[Tetramethyl(Phenyl)Cyclopentadienyl]-Titanium(III)

摘要

Dichlorobis[#eta#~5-tetramethyl(phenyl)cyclopentadienyl]titanium(IV) (1) and chlorobis[#eta#~5-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 [(C_5Me_5)_2TiCl_2] and [(C_5Me_5)_2TiCl], respectively. ESR spectra of 2 in 2-methyltetrahydrofuran (MTHF) solutions and glasses revealed that 2 coordinates MTHF to give [(C_5Me_4Ph)_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 ((C_5Me_4R)_2TiCl) to -wards MTHF: Ph > SiMe_3 > H > Me.