Linear, mixed-valent homocatenated tri-tin complexes featuring Sn–Sn bonds

Abstract

A series of tri-tin complexes (L^PhSn)₃X with triple-decker structures (L^Ph = 2,5-di(o-pyridyl)-3,4-diphenylpyrrolate; X = Cl, AlCl₄, OTf, and PF₆) was synthesized by reducing L^PhSnCl with LiB^sBu₃H and subsequent reactions. Structural characterization of (L^PhSn)₃Cl revealed a Sn–Sn–Sn core, and DFT calculations suggest that its HOMO is primarily σ-bonding along the tri-tin framework. (L^PhSn)₃Cl reacts with W(CO)₅THF to afford (L^PhSn)₂(W(CO)₅)₂ and L^PhSnCl, implying that (L^PhSn)₃Cl may exhibit dynamic behavior in solution.