Molecular Bis(chalcogenido) Titanates of Te, Se, and\nS

A series\nof titanate cisoid bis(chalcogenidos) (Ch = Te, Se, and\nS) complexes supported by the β-diketiminate ligand BDI<sup>–</sup> = [ArNC(CH<sub>3</sub>)]<sub>2</sub>CH (Ar = 2,6-<sup>i</sup>Pr<sub>2</sub>C<sub>6</sub>H<sub>3</sub>) are readily assembled\nvia treatment of the Ti<sup>III</sup> precursor (BDI)Ti(CH<sub>2</sub>SiMe<sub>3</sub>)<sub>2</sub> with 2.5 equiv of elemental “Ch”\nsource and 1 equiv of reductant in the presence of crown-ether. In\nthe absence of the electride, Te or S addition to (BDI)Ti(CH<sub>2</sub>SiMe<sub>3</sub>)<sub>2</sub> results instead in the isolation of\na mononuclear tellurido-tellurolate [(BDI)Ti(=Te)(TeCH<sub>2</sub>SiMe<sub>3</sub>)] and the bridging sulfido-thiolate complex [(BDI)Ti(SCH<sub>2</sub>SiMe<sub>3</sub>)(μ-S)]<sub>2</sub>, respectively. In\nthe case of Se, the rare selenido-perselenoate complex [(BDI)Ti(=Se)(η<sup>2</sup>-SeSeCH<sub>2</sub>SiMe<sub>3</sub>)] was isolated. In addition\nto crystallographically and spectroscopically characterizing all of\nthe complexes, we demonstrate the latter species to be likely intermediates\nin the formation of [(BDI)Ti(Ch)<sub>2</sub>]<sup>−</sup> via\nthe addition of electride.