17940-08-8Relevant articles and documents
CYCLISCHE DIAZASTANNYLENE. XVII. ZUR UMSETZUNG EINES 1,3-DIAZA-2-SILA-4λ2-STANNETIDINS MIT CYCLISCHEN DIENEN
Veith, M.,Toellner, F.
, p. 219 - 226 (1983)
1,3-Di-t-butyl-2,2-dimethyl-1,3,2,4λ2-diazasilastannetidine (I) adds cyclopentadiene across one of the tin-nitrogen bonds forming compound III in which the tin atom attains noble gas electron configuration.While one of the nitrogen atoms acts as an acceptor for the proton, the cyclopentadienyl is coordinated to the electrophilic tin center.As shown by temperature dependent 1H NMR techniques III has fluctuating properties in solution.When 2 moles of cyclopentadiene are allowed to react with I dicyclopentadienyltin(II) (IV) can be synthesized in high purity besidesdimethylbis(t-butylamino)silane (II).IV also results together with II and the dimeric tin-di-t-butoxide (V), when III is treated with t-butyl alcohol.Substitution of the hydrogen atom in III can not be achieved with methyllithium: in this case III decomposes to I, lithium cyclopentadienide and methane.I oxidizes 1,3-cyclohexadiene quantitatively to benzene at 80 deg C: the other products in this reaction are found to be β-Sn and the diamine II.This redox reaction is remarkable in a double sense: first of all it may be a convenient route for aromatization and secondly it is the first example of I acting as an oxidant.
Halide-complexing characteristics of germa- and stannaimine cages
Veith, Michael,Fischer, Joachim,Prout, Timothy R.,N?tzel, Martin,Hobein, Peter,Huch, Volker
, p. 4130 - 4135 (2008/10/08)
The cations M3(N-t-Bu)4H3+ (M = Ge, Sn) coordinate very efficiently via hydrogen bridges to chloride, bromide, and iodide anions. These molecular complexes have the general formula M3(N-t-Bu)4H3X (M = Ge, X = Cl (1), Br (2), I (3); M = Sn, X = Cl (4), Br (5), I (6)) and are obtained by three different methods. The newly synthesized compounds have been thoroughly characterized by IR, NMR, and mass spectroscopy. X-ray crystal structure determinations of 1, 3, 4, and 5 reveal the molecules to be built of a M3N4-norcubane-type skeleton, which is attached by nitrogen-hydrogen bonds to a H3X trigonal pyramid. The overall closed cage "M3N4H3X" has an approximate 3m (C3v) symmetry with one nitrogen and the halogen atom situated on the 3-fold axis. The compounds 3 and 4 crystallize isotypically with 0.5 benzene/molecule in the space group R3 with a = b = 11.990 (7) ?, c = 34.40 (1) ?, α = β = 90°, γ = 120°, Z = 6, and V = 4283 (2) ?3 and a = b = 11.720 (8) ?, c = 35.109 (15) ?, α = β = 90°, γ = 120°, Z = 6, and V = 4176 (2) ?3, respectively, with the final R factors being 0.057 (1369 reflections) and 0.032 (1152 reflections). Compound 1 crystallizes in the monoclinic space group P21/n with a = 10.188 (6) ?, b = 19.923 (8) ?, c = 12.099 (7) ?, β = 91.54 (5)°, Z = 4, and V= 2455 (1) ?3. A total of 2859 independent data were collected, giving a final R factor of 0.035. Compound 5 is orthorhombic (space group Pnma) with a = 21.471 (9) ?, b = 11.753 (6) ?, c = 10.476 (5) ?, Z = 4, and V = 2644 (1) ?3. Refinement of this structure, using 1921 independent reflections, gave an R factor of 0.033. The compounds can be described as being composed of a spherical lipophilic part (M3(N-t-Bu)4) and a somewhat protruding lipophobic part (H3X pyramid). These properties seem to account for the ease with which these cages exchange the halogen anions in metathesis reactions with simple salts like NaBr, NaI, and TlCl.
