A Versatile Synthetic Route for Cyclopentadienyl−Amido Titanium(IV) Compounds. NMR Spectroscopy Study and X-ray Molecular Structure of [Ti{η5-C5H4SiMe2NMe(CH2)2-η-NMe}Cl2]

The reaction of the chlorosilyl-substituted cyclopentadienyltitanium compound [Ti(η5-C5H4SiMe2Cl)Cl3] with N,N‘-dimethylethylenediamine in the presence of 2 equiv of NEt3 gave a mixture of two complexes, [Ti{η5-C5H4SiMe2NMe(CH2)2-η-NMe}Cl2] (1) and [Ti{η5-C5H4SiMe2-η-N(CH2)2-η-NHMe}Cl2] (2), in a molar ratio of 3:1. However, a similar reaction with N-methylethylenediamine afforded complex 2 regiospecifically. The dialkyl derivatives [Ti{η5-C5H4SiMe2NMe(CH2)2-η-NMe}R2] (R = Me (3), CH2Ph (4)) were prepared by reacting the dichloride complex 1 with 2 equiv of MgClMe or 1 equiv of Mg(CH2Ph)2·2THF, respectively. The analogous reaction with LiNMe2 afforded the diamido derivative [Ti{η5-C5H4SiMe2NMe(CH2)2-η-NMe}(NMe2)2] (5) in high yield. Complex 1 reacts with dry CO2 via insertion of a molecule of CO2 into each of the Ti−N and Si−N bonds to yield the dicarbamate compound [Ti{(η5-C5H4SiMe2OC(O)NMe(CH2)2NMe(η2-CO2)}Cl2] (6), in which the carbamate groups are bound in η2- and η1-fashion. Thermal decomposition of ...