0000000000542340
AUTHOR
Axel Blecher
Molekül- und kristallstruktur von hexamethylcyclo-tristannaselenan [(CH3)2SnSe]3
Hexamethylcyclotristannaselenane [(CH3)2SnSe]3 forms tetragonal crystals, space groups P41212, with a 986.5(2), c 1769.7(4) pm, Z 4. The complete X-ray structural analysis (two independent determinations) shows the six-membered ring to have a twist-boat conformation similar to [(CH3)2SnS]3. The SnSe2C2 tetrahedra are only slightly distorted, the mean bond distances being SnSe 253.1 (251.7⋯254.0(4)) pm, Sn C 2.13 (2.09⋯2.17(3)) pm. Conformational details are discussed.
Fourier transform nmr investigations of organotin compounds
Abstract NMR spectra have been obtained for fiteen title compounds, mainly with R = Me. Tin chemical shifts were found to lie within the expected ranges, but to vary little with R or, apparently, with change in ring size. While the magnitute of 1 (SnSe) was as predicted, the of 1 (SnTe) was more than twice as large as that previously observed for (Me 3 Sn) 2 Te. In compounds Me 6 Sn( 3 X 3 , 2 J(SnMSn) varied systematically with variations in x, but within relatively narrow limits (195-250 Hz); a much more drastic variation was observed for Me 6 Sn 3 X 2 , possibly due to bond angle changes at Sn and X.