A bipyridyl thorium metallocene: synthesis, structure and reactivity

Abstract

The synthesis, structure and reactivity of a new bipy thorium metallocene have been studied. The reduction of the thorium chloride metallocene [η⁵-1,3-(Me₃C)₂C₅H₃]₂ThCl₂ (1) with potassium graphite in the presence of 2,2′-bipyridine gives the purple bipy metallocene [η⁵-1,3-(Me₃C)₂C₅H₃]₂Th(bipy) (2) in good yield. Complex 2 has been fully characterized by various spectroscopic techniques, elemental analysis and X-ray diffraction analysis. Complex 2 reacts cleanly with trityl chloride, silver halides and diphenyl diselenide, leading to the halide metallocenes [η⁵-1,3-(Me₃C)₂C₅H₃]₂ThX₂ (X = Cl (1), Br (3), I (4)) and [η⁵-1,3-(Me₃C)₂C₅H₃]₂Th(F)(μ-F)₃Th[η⁵-1,3-(Me₃C)₂C₅H₃](F)(bipy) (5), and selenido metallocene [η⁵-1,3-(Me₃C)₂C₅H₃]₂Th(SePh)₂ (6), in good conversions. In addition, 2 cleaves the CS bond of CS₂ to give the sulfido complex, [η⁵-1,3-(Me₃C)₂C₅H₃]₂ThS (7), which further undergoes an irreversible dimerization or nucleophilic addition with CS₂, leading to the dimeric sulfido complex {[η⁵-1,3-(Me₃C)₂C₅H₃]₂Th}(μ-S)₂ (8) and dimeric trithiocarbonate complex {[η⁵-1,3-(Me₃C)₂C₅H₃]₂Th}(μ-CS₃)₂ (10) in good yields, respectively.