Synthetic Studies and Structural Aspects of Dinuclear Sulfur Titanium Compounds

A series of dinuclear sulfur‐bridged titanium derivatives [Ti(η 5 ‐C 5 Me 5 )R(μ‐S)] 2 (R=NMe 2 ( 1 ), Ph ( 2 ), CH 2 Ph ( 3 ), CH 2 SiMe 3 ( 4 )) has been synthesized from the reaction of [Ti(η 5 ‐C 5 Me 5 )Cl(μ‐S)] 2 with the corresponding lithium salt or Grignard reagent. Formulation of 1 – 4 as symmetric dimers has been confirmed by crystallographic studies. The analogous reaction with Mg(C 3 H 5 )Cl afforded the paramagnetic mixed‐valence Ti(III)/Ti(IV) compound [{Ti(η 5 ‐C 5 Me 5 )(μ‐S)} 2 (μ‐C 3 H 5 )] ( 5 ). Contrasting with complexes 1 – 4 , compound 5 exhibits a bridging μ‐CH 2 CHCH 2 fragment between the titanium atoms, which prevents the formation of a planar Ti 2 S 2 core in the solid‐state structure. Complex 1 reacts with SiH 3 Ph to give [{Ti(η 5 ‐C 5 Me 5 )(μ‐S)} 2 (μ‐NMe 2 )] ( 6 ), a paramagnetic mixed‐valence Ti(III)/Ti(IV) compound, structurally and electronically similar to 5 . Under mild conditions, treatment of compounds 3 and 4 with H 2 (1 atm) generates quantitatively the Ti(III) tetrametallic sulfide cluster [Ti(η 5 ‐C 5 Me 5 )(μ 3 ‐S)] 4 , along with the corresponding alkane.