Bis(μ-η5:η5-1,4-bis(trimethylsilyl)cyclooctatetraene)dititanium-the first compound with a strong Ti-Ti bond
1999
Abstrakt
Reduction of [Ti(η8-C8H6(SiMe3)2)(μ-Cl)}2(THF)] by magnesium gave the title compound with an extremely low Ti-Ti distance. The reduction of {[η(8)-1,4-(SiMe3)(2)C8H6]Ti(μ-Cl)}(2)(THF) by magnesium in the presence of bis(trimethylsilyl)acetylene in tetrahydrofuran affords diamagnetic bis[μ-η(5):η(5)-1,4-bis(trimethylsilyl)cyclooctatetraenetitanium](Ti-Ti) (1) in low yield.
The X-ray crystal analysis of 1 revealed that bridging cyclooctatetraene ligands in the centrosymmetric dimer are concave-bent. An extremely short Ti-Ti distance of 2.326(2) Angstrom is compatible with the presence of a double Ti-Ti bond.