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  • 1
    Electronic Resource
    Electronic Resource
    Organotin cations stabilized by π coordination - synthesis and NMR studies in solution and in the solid state (1992)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 125 (1992), S. 1597-1603 
    Details
    ISSN: 0009-2940
    Keywords: Organoboration ; Tin compounds ; NMR, multinuclear ; NMR, 119Sn ; NMR, solid-state ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The organoboration of tetraalkynyltin compounds [Sn-(C≡CR1)4 (1): R1 = Me (a), Et (b), Pr (c), iPr (d), tBu (e)] with triethylborane (2) proceeds stepwise. Intermediates with a cationic triorganotin (3, 5) and a dicationic diorganotin fragment (4), stabilized by intramolecular coordination of one and two alkynyl moieties, respectively, were isolated (3e, 4a) and/or identified by multinuclear NMR in solution (1H, 11B, 13C, 119Sn) and in the solid state (13C and 119Sn CP/MAS) (3e, 4a). The magnitude of 1J(13C≡13C) in 4a (101.0 Hz) is significantly smaller than that for sodium triethyl-1-propynylborate (7) (119.2 Hz), proving the weak coordination of the C≡C bond to the dicationic tin fragment. The final products of the organoboration, 1,4,6,9-tetraalkyl-2,7-bis(diethylboryl)-3,8-diethyl-5-stannaspiro[4.4]nona-1,3,6,8-tetraenes (6b-6e) were obtained in high yield.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19921250714
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  • 2
    Electronic Resource
    Electronic Resource
    Organoborierung von Tetrakis(trimethylsilylethinyl)stannan - Röntgenstrukturanalyse eines 5-Stannaspiro[4.4]nona-1,3,6,8-tetraen-Derivates[1] (1992)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 125 (1992), S. 643-650 
    Details
    ISSN: 0009-2940
    Keywords: Organoboration ; Tin, alkynyl compounds ; Spiro-tetraorganotin compounds ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Organoboration of Tetrakis(trimethylsilylethynyl)stannane - X-ray Structure of a 5-Stannaspiro[4.4]nona-1,3,6,8-tetraene DerivativeTetrakis(trimethylsilylethynyl)stannane (1) reacts with non-cyclic trialkylboranes BR3 [2, R = Me (a), Et (b), Pr (c), iPr (d)] and 9-alkyl-9-borabicyclo[3.3.1]nonanes[2e (alkyl = Et), 2f (alkyl = neopentyl)] to give the 3,8-dialkyl-2,7-bis(dialkylboryl)-1,4,6,9-tetrakis(trimethylsilyl)-5-stannaspiro[4.4]nona-1,3,6,8-tetraenes 5a to f in high yield. The reaction proceeds stepwise, and intermediates as well as final products were characterized by 1H, 11B, 13C, 29Si, 119Sn NMR spectroscopy. According to an X-ray structure analysis of 5f · 0.5 CH2Cl2 (space group P2/c) the endocyclic CSnC bond angles are small [84.9(2) and 84.2(2)°] and the two five-membered rings are not exactly planar. Steric crowding causes a strong twist of the skeleton of the other ring systems. The agreement between solid-state and liquid-phase NMR data shows that main structural features are retained in solution.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19921250316
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  • 3
    Electronic Resource
    Electronic Resource
    η5-Cyclopentadienyl derivatives of tin(II) studied by two-dimensional multinuclear magnetic resonance in solution and by 13C and 119Sn CP/MAS NMR in the solid state (1992)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 30 (1992), S. 964-968 
    Details
    ISSN: 0749-1581
    Keywords: Determination of coupling signs ; Multinuclear two-dimensional NMR ; Pseudo-triple-resonance experiments ; Solid-state ; 119Sn CP/MAS NMR ; Cyclopentadienyltin(II) compounds ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Absolute coupling signs of 1J(119Sn, 13C) (〈O) and 2J(119Sn, 1H) (〈O) in (n5-C5H5)2Sn (1) and 1J(119Sn, 13C) (〈O)2J(119Sn, 13C) (〈O) and 3J(119Sn, 1H) (〉O) in (n5-C5Me5)2Sn (2) were determined using advanced direct and indirect two-dimensional methods. These are based on Ψ-BIRD techniques and z-filtering, leading to pseudotriple-resonance experiments of the type 1H{119Sn(13C)} and 13C{1H(119Sn)}, respectively. A mixed n5-cyclopentadienyltin(II) amide was prepared and characterized by 1H, 13C, 29Si and 119Sn NMR in solution in the presence of its symmetrical redistribution products 1 and [(Me3Si)2N]2Sn. Solid-state 119Sn CP/MAS NMR spectra of 1 shows the presence of two tin sites (in accord with the x-ray analysis) with a 62.2 ppm difference in 119Sn chemical shifts, the mean value being in close agreement with the solution-state δ119Sn value. The symmetries of the shielding tensor for the two tin sites are different and there appears to be a correlation between this property and the ring centroid - Sn - ring centroid angle α. 13C CP/MAS NMR proved insensitive to the structural differences between the two types of molecules of 1 in the unit cell.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1260301010
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