Beeinflussen interne N-Donorliganden Hydrolyse-und Kondensationsreaktionen von Chlorsilanen? / Do Internal N-Donor Ligands Influence the Hydrolysis and Condensation Reactions of Chlorosilanes?

Abstract

The reaction of [C6H4CH2N(CH3)2]2SiCl2 (1) with hydrogen chloride gives the singly protonated adduct 2. Its solid state structure has been determined by single crystal X-ray dif fraction. Centrosymmetric 2 is orthorhombic, space group Pbca, a = 1694.9(2), b = 1161.7(2), c = 2501.7(3) pm; Z -8. Controlled hydrolysis of 1 leads to the 1,3-siloxanediol 4, probably via the precursors 3 a -3 c which could not be isolated. The hydrogen chloride formed during the hydrolysis protonates two of the dimethylamino groups, while the other two dimethylamino functions form hydrogen bonds to the silanol groups. Centrosymmetric 4: monoclinic, space group P 2Jc, a = 980.

Comparison of Phosphorus and Silicon: Hypervalency, Stereochemistry, and Reactivity

“…Although not indicated by the authors, at least the initial step in the hydrolysis may proceed by nucleophilic attack of water to give a hexacoordinated activated state similar to that proposed, i.e . j , for the hydrolysis of [Mes 2 SiF 3 ] - ( 94 ) …”

“…Successive loss of HF leads to as intermediates which may combine to yield the hydrogen bisilonate with concurrent loss of fluoride ion. Somewhat related to the hydrolysis of Mes 2 SiF 3 -, 94, Auner and coworkers 173 studied the controlled hydrolysis of the dichlorosilane 97 which resulted in the formation of the 1,3-siloxanediol 98. An X-ray structure of the protonated salt of 97, i.e., 99, and that of the product 98 suggested a reaction mechanism incorporating N f Si donor action (Scheme 3).…”

“…An X-ray structure of the protonated salt of 97, i.e., 99, and that of the product 98 suggested a reaction mechanism incorporating N f Si donor action (Scheme 3). 173 The structure of the pentacoordinate silane 97 containing two aromatic and three electronegative components may be compared to a similar ligand constitution for anionic Mes 2 SiF 3 -(94). 172 Likewise, the X-ray structures of the hydrolysis products, the siloxanediol 98 and the siloxane 96, are comparable.…”

Conformational Preferences of 1,3-Diferrocenyl-1,1,3,3-tetramethyldisiloxane and Its Cocrystal with Ferrocene: A Theoretical and Crystallographic Study of the Role of Intra- and Intermolecular Interactions

“…A review (up to 1996) of the Cambridge Crystal Data Base records 95 structures containing the Si−O−Si linkage. The mean Si−O−Si angle is 156.6°, with a range from 128.6°14a to 180.0°. 14b,c As noted by others, an increase in the Si−O−Si angle, i.e., from 2 (141.5(1)°) to 1 (159.9(2)°), parallels a Si−O bond length decrease: 2 (1.646(2), 1.636(2)) Å; 1 (1.618(2), 1.627(2) Å) 14d 1 (a) Structure of 1,3-diferrocenyl-1,1,3,3-tetramethyldisiloxane ( 1 ).…”

Facile syntheses, structural characterizations, and isomerization of disiloxane-1,3-diols

“…The 1 H NMR resonance of hydroxy group for 3 was observed at 9.98 ppm. The similar reaction was carried out in the absence of an acid acceptor by Auner et al [15] to give disiloxane-1,3-diolÕs salt, 3 Á 2HCl recrystallized from n-pentane. Belzner [16] also synthe- [8] 2, 72%, R = phenyl 3, 65%, R = dimethylaminomethylphenyl 4, 68%, R = methyl Scheme 2.…”