Synthesis, characterisation, crystal structure, reactivity and bonding in titanium complexes containing 2,3,4,5-tetramethylpyrrolyl

The complex [Ti(η 5 -NC 4 Me 4 )Cl 3 ] 1 has been synthesized, characterised and used as a precursor for the preparation of the bis(pyrrolyl) complex [Ti(η 5 -NC 4 Me 4 ) 2 Cl 2 ] 2 and the thiolate complexes [Ti(η 5 -NC 4 Me 4 )(SPh) 3 ] 3 and [Ti(η 5 -NC 4 Me 4 )(SPh)Cl 2 ] 4. The η 5 co-ordination of the heterocyclic ring was predicted by the 13 C NMR data and confirmed by the structure determination of complexes 1 and 3, which present a piano-stool conformation and a slippage of the pyrrolyl towards the titanium. The mixed-ring complex [Ti(η 5 -C 5 H 5 )(η 5 -NC 4 Me 4 )Cl 2 ] 5 has also been synthesized and its structure determined, revealing a distorted pseudo-tetrahedral geometry and slippage of the heterocyclic ring.