SYNTHESIS AND STRUCTURE OF CRYSTALLINE [K(SN(CH2BUT)3)(ETA-C6H5ME)3] AND THE 1ST NMR SPECTRAL OBSERVATION OF SN-119-K-39 COUPLING

Treatment of [Sn2(CH2But)6] with K in tetrahydrofuran (thf) at 25-degrees-C affords crystalline [K{Sn(CH2But)3}(thf)2] 1, which with toluene gives [K{Sn(CH2But)3}(eta6-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 eta6-toluene molecules as occupying a single site), with I(K-Sn) 3.548(3) angstrom and I(K-C) ranging from 3.21 to 3.72 angstrom; a solid state Sn-119 cross-polarisation magic angle spinning (CP-MAS) NMR spectral study of 2 provides the first observation of direct Sn-119-K-39 coupling.