0000000000009908
AUTHOR
Barbara M. Schmidt
Dimeres und Trimers 1-Methyl-1-aza-5-stannabicyclo[3.3.01,5]-octan sulfid [MeN(CH2CH2CH2)2SnS]n, Röntgenstrukturanalyse des Dimeren und Gleichgewicht Dimer-Trimer gemäß 119Sn-NMR und FD-Massenspektrometrie
Abstract The crystal structure of the dimeric title compound has been determined and refined to R = 0.0266. The core of the nearly centrosymmetric dimer is formed by an almost perfect [SnS]2 rectangle (Sn-S 2.39 and 2.51 A). The two sulfur atoms of this rectangle establish the connecting edge of two distorted trigonal bipyramids around the two tin atoms (Sn … N 2.55 A). Solutions of the title compound contain in addition to the dimer (σ(119Sn) = −4.6 ppm) about 20% of the trimer (+ 10.3 ppm). By quick crystallization a mixture of both oligomers can be transferred into the solid state.
Über blei-haltige Heterocyclen
Abstract Crystal structures of alternating six-membered rings [Ph2PbS]3-P21/c and [Ph2SnS]3-P21/n have been determined by X-ray methods. Both heterocycles exhibit a C2-symmetric twisted boat conformation with tetrahedral coordination of the metal atoms [dPbS 2.491 A (dSnS 2.401 A, dPbC 2.19 A (dSnC 2.129 A)]. No additional intermolecular contacts have been found. A ring-segment exchange reaction in solution has been observed by NMR. In the resulting equilibrium new cyclic compounds containing both tin and lead atoms with coupling constants 2J(207PbS119Sn) 226 Hz have been detected. FD-mass spectra indicate formation of dimeric molecular units.
Über bismut-haltige heterocyclen
Abstract Methyl and phenyl oxadithia and trithiabismocanes have been synthesized from methyl or phenyl diethoxybismutane and the respective dithiol. The light-sensitive compounds have been investigated by mass, vibrational and 13C NMR spectra: ν(BiMe) 470–460, ν(BiS2) 300–240 cm−1; δ(13Me) −12 ppm. The crystal structure of 5-phenyl-1,4,6,5-oxadithiabismocane has been determined (R = 0.056). The eight-membered ring has the chair-chair conformation. Besides three direct bonds (BiPh 225(2), BiS 256.0(2) and 260.2(3) pm) there are one transannular (Bi⋯O 297(1) and two intermolecular contacts (Bi ⋯S 344.0(3) and 350.9(3) pm) to bismuth in resulting a ψ-monocapped octahedral sphere of coordina…