5181-43-1Relevant articles and documents
Dispersion-energy-driven Wagner-Meerwein rearrangements in oligosilanes
Albers, Lena,Rathjen, Saskia,Baumgartner, Judith,Marschner, Christoph,Müller, Thomas
, p. 6886 - 6892 (2016)
The installation of structural complex oligosilanes from linear starting materials by Lewis acid induced skeletal rearrangement reactions was studied under stable ion conditions. The produced cations were fully characterized by multinuclear NMR spectroscopy at low temperature, and the reaction course was studied by substitution experiments. The results of density functional theory calculations indicate the decisive role of attractive dispersion forces between neighboring trimethylsilyl groups for product formation in these rearrangement reactions. These attractive dispersion interactions control the course of Wagner-Meerwein rearrangements in oligosilanes, in contrast to the classical rearrangement in hydrocarbon systems, which are dominated by electronic substituent effects such as resonance and hyperconjugation.
Sterically overcrowded or charge perturbed molecules. XXIII. Hexakis(trimethylsilyl)disilane: structure and photoelectron spectrum of a sterically overcrowded molecule
Bock, Hans,Meuret, Jochen,Ruppert, Klaus
, p. 19 - 28 (1993)
Hexakis(trimethylsilyl)disilane 3Si-Si3 crystallizes in the rhombohedral space group Rc with six molecules of D3 symmetry per unit cell.The steric overcrowding by the 18 peripheral methyl groups shows up especially in the elongation of the central SiSi bond to 240 pm, in the differing dihedral angles ω(SiSi-SiSi) of 43 deg and 77 deg and in the rather short non-bonded C...C distances of only 352 pm,which reveals an inter-penetration of the methyl groups within their van der Waals radii of about 200 pm.The 1H nuclear magnetic resonance (NMR) spectrum in DCCl3 at 190 K, however, does not exhibit any signal splitting of the 42 equivalent methyl hydrogens and so the rotational barriers must be below 20 kJ mol-1.The photoelectron spectrum shows in its low-energy region between 7.2 eV and 9.3 eV a resolved αSiSi ionization pattern, which can be satisfactorily reproduced by a LCBO-MO model parametrized in terms of the different SiSi/SiSi bond interactions, and the higher ionization energies are assigned on the basis of a radical cation state comparison with 3SiCl, (H3C)3SiCl and (H3C)3CCl.Although the first vertical ionization energy is only 7.70 eV, which is the lowest observed so far a disilane derivative, and in accord with the cyclovoltammetrically determined irreversible first oxidation potential, no persistent radical cation of hexakis(trimethylsilyl)disilane can be generated in solution.
Synthesis, characterization and reactivity of yttrium and gadolinium silyl complexes
Sgro, Michael J.,Piers, Warren E.
, p. 243 - 250 (2014/12/10)
The syntheses of yttrium and gadolinium-silyl complexes of the form R(Me3Si)2SiMI2(THF)3 (M = Y, Gd; R = Et, SiMe3) through reactions of potassium silyl reagents, KSiR(SiMe3)2(TH
Sodium-potassium alloy for the reduction of monoalkylaluminum(III) compounds
Schormann, Mark,Klimek, Klaus S.,Hatop, Hagen,Varkey, Saji P.,Roesky, Herbert W.,Lehmann, Christopher,Roepken, Cord,Herbst-Irmer, Regine,Noltemeyer, Mathias
, p. 225 - 236 (2008/10/08)
Monoalkylaluminum(III) compounds of the type RAIX2 {R = Cp* (C5Me5), X = Cl, Br, I (1-3); (BisAlCl2)2 (Bis = (Me3Si)2CH) (5); TrisSi [(Me3Si)3Si], X = Cl, B
