- Geminal bis(haloorganostannanes) and their complexation as mono- and bidentate Lewis acids with dimethyl sulfoxide
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Six (chloromethylstannyl)methanes with structures CH2(SnMenCl3-n)(SnMemCl 3-m) with n = 0-3 and m = 0-2 have been prepared by chlorine-methyl exchange from bis(trimethylstannyl)methane or bis-(trivinylstannyl)methane. Four 2,2-bis(chloromethylstannyl)propanes have been similarly prepared from 2,2-bis(trimethylstannyl)propane. Correlations between 1H and 13C magnetic resonance parameters have been examined. The effects of dimethyl sulfoxide (Me2SO) on the 1H NMR parameters of the chloro stannanes have been examined as a source of information on complexation. Seven complexes with Me2SO have been prepared, and the structures of CH2(SnMeCl2)-(SnMe2Cl)(Me5SO) λ4, CH2(SnMeCl2)2(2Me2SO) λ5, and CH2(SnCl3)2(4Me2SO) λ7 have been determined by X-ray diffraction. In the first of these, the oxygen of the Me2SO bridges the two tins which display distorted trigonal-bipyramidal geometry; in the second, the oxygens of each Me2SO act as bridges between the tins which display distorted octahedral geometry; in the third, the oxygens do not bridge and the CH2 group serves as a common apex for the octehedra of two hexacoordinate tins. Pertinent features of the structures are discussed. Compound 4 crystallizes in the space group P1 with a = 7.551 (2) A?, b = 7.945 (2) A?, c = 13.354 (3) A?, α = 80.63 (2)°, β = 89.13 (2)°, γ = 72.96 (2)°, and Z = 2. The structure solution and refinement were based on 1609 reflections with Fo > 6σ(Fo) to give a discrepancy factor of 0.045. Compound 5 crystallizes in the orthorhombic space group Pbnm with a = 9.821 (2) A?, b = 12.411 (2) A?, c = 15.540 (3) A?, and Z = 4. Refinement based on 1109 reflections with Fo > 6σ(Fo) converged at 0.048. Compound 7 crystallizes in the monoclinic space group C2/c with a = 20.998 (5) A?, b = 7.925 (3) A?, c = 16.535 (4) A?, β = 98.79 (3)°, and Z = 4. Refinement using 1277 reflections with Fo, > 6σ(Fo) yielded R = 0.034.
- Karol, Thomas J.,Hutchinson, John P.,Hyde, Jeffrey R.,Kuivila, Henry G.,Zubieta, Jon A.
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p. 106 - 114
(2008/10/08)
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