Solid-State ²⁹Si NMR Study of RSiSiR:  A Tool for Analyzing the Nature of the Si−Si Bond

Abstract

The first solid state 29Si NMR of a disilyne, that is, RSiSiR, R = Si(CH(SiMe3)2)2(i-Pr) (1) was measured: delta11 = 364 +/- 20; delta22 = 221 +/- 16 and delta33 = -350 +/- 13; CSA = -643 ppm. These measured values as well as calculations for model disilynes strongly support the description of the Si-Si bond in bent disilynes as a triple bond, although with weakened pi-bonds and a reduced bond order of 2.6.

[{2,6‐(Me2NCH2)2C6H3}Sn]2: An Intramolecularly Coordinated Diorganodistannyne

“…On the basis of a solid-state 29 Si NMR study, a silicon analogue favors the existence of a triple bond. [28] UV/Vis absorptions and molecular orbital calculations suggest that Ar'MMAr'compounds (M = Ge, Sn; Ar' = C 6 H 3 -2,6-(C 6 H 3 -2,6-iPr 2 ) 2 ) possess multiple bonds in solution. [27] The successful synthesis of the compounds mentioned above is related to the employment of rather bulky substituents such as a variety of substituted aryl and organosilyl groups, giving rise to kinetic stabilization.…”

A Donor‐Stabilized Silanethione or a Si‐Substituted N‐Heterocyclic Platinum Carbene?

“…[12] In addition to the isotropic shift value characteristic of tetracoordinate silicon compounds (d iso = À2.7 ppm) the remarkably large span of the signal (W = 256 ppm) indicates a noticeable anisotropy of the contributions of the substituents to the shielding of the 29 Si nucleus, [13,14] hence indicating contributions of the silanethione canonical form to the overall bonding situation.…”

[{2,6‐(Me2NCH2)2C6H3}Sn]2: ein intramolekular koordiniertes Diorganodistannin

“…[24][25][26][27] Auf der Basis einer 29 Si-Festkörper-NMRStudie wird für das Silicium-Analogon die Dreifachbindung favorisiert. [28] UV/Vis-Absorptionen und Molekülorbital-rechnungen deuten darauf hin, dass Verbindungen des Typs Ar'MMAr' (M = Ge, Sn; Ar' = C 6 H 3 -2,6-(C 6 H 3 -2,6-iPr 2 ) 2 ) Mehrfachbindungen in Lösung aufweisen. [27] Die erfolgreiche Synthese der genannten Verbindungen ist assoziiert mit der Verwendung sterisch sehr anspruchsvoller Substituenten, z.…”