Synthesis and structure of crystalline [K{Sn(CH2But)3}(η-C6H5Me)3] and the first NMR spectral observation of 119Sn–39K coupling

Abstract

Treatment of [Sn₂(CH₂Bu^t)₆] with K in tetrahydrofuran (thf) at 25 °C affords crystalline [K{Sn(CH₂Bu^t)₃}(thf)₂]1, which with toluene gives [K{Sn(CH₂Bu^t)₃}(η⁶-C₆H₅Me)₃]2, the X-ray structure of 2 at 295 K revealing that potassium is in a distorted tetrahedral environment (taking each of the η⁶-toluene molecules as occupying a single site), with l(K–Sn) 3.548(3)Å and l(K–C) ranging from 3.21 to 3.72 Å; a solid state ^1l9Sn cross-polarisation magic angle spinning (CP-MAS) NMR spectral study of 2 provides the first observation of direct ¹¹⁹Sn–³⁹K coupling.