Synthesis and structural features of [(C 5H 4CMe 2NMe 2) 2TiCl], a bis(cyclopentadienyl)Ti(III) complex with internal dimethylamino coordination

• Published in: Journal of organometallic chemistry 2003-06, Vol.676 (1), p.1-7
• Main Authors: Kotov, Vasily V, Fröhlich, Roland, Kehr, Gerald, Erker, Gerhard
• Format: Article
• Language: English
• Subjects: Bent metallocenes; Ferrocenes; Functionalized cyclopentadienides; Intramolecular coordination
• ISSN: 0022-328X; 1872-8561
• DOI: 10.1016/S0022-328X(03)00221-3

Treatment of 6-dimethylamino-6-methylfulvene ( 1) with methyllithium gave the [C 5H 4CMe 2NMe 2]Li product ( 2) that was characterized by X-ray diffraction. Compound 2 features an oligomeric chain structure with the [C 5H 4CMe 2NMe 2] unit serving as a bridging ligand using its Cp anion moiety and the NMe 2 donor functionality. Treatment of 2 with FeCl 2 yielded the substituted ferrocene 3. The corresponding reaction of 2 with TiCl 4(THF) 2 gave the titanocene complex (C 5H 4CMe 2NMe 2) 2TiCl 2 ( 4) that exhibits an ordinary bent metallocene structure in the solid state without involvement of the pendant CMe 2NMe 2 donor ligands. In contrast, the titanium(III) complex (C 5H 4CMe 2NMe 2) 2TiCl ( 5), obtained from the reaction of 2 with TiCl 3(THF) 3, has one of the two nitrogen donors strongly coordinated to the metal center. In the crystal, complex 5 thus attains a typical pseudotetrahedral Group 4 bent metallocene structure, as shown by an X-ray crystal structure analysis. Treatment of the oligomeric reagent [C 5H 4CMe 2NMe 2]Li ( 2) with TiCl 3(THF) 3 gives the titanium(III) complex (C 5H 4CMe 2NMe 2) 2TiCl ( 5) that adopts a pseudotetrahedral bent metallocene structure in the crystal where one of the pendant CMe 2NMe 2 amino donor ligands is intramolecularly coordinated to the titanium center.