Tetra(alkynyl)silanes, a 3,6-Disila-triyne, a 3,6,9-Trisila-tetrayne, a 1,3,4,6-Tetrasiladiyne, and Bis(trimethylstannyl)ethyne. Molecular Structures and Solid-state NMR Studies

Abstract

The molecular structures of three alkynylsilanes, tetrakis(ethynyl-p-tolyl)silane, 3,3,6,6,-tetramethyl- 3,6-disila-triyne, 3,3,6,6,9,9,-hexamethyl-3,6,9-trisila-tetrayne, and of bis(trimethylstannyl)- ethyne have been determined by X-ray diffraction. The same alkynylsilanes, and in addition 1,2- bis(trimethylsilylethynyl)-1,1,2,2-tetramethyldisliane, were studied by solid-state 13C and 29Si MAS NMR spectroscopy. The results of these measurements were compared with crystallographic evidence and also with relevant solution-state NMR data.

Tridentate Lewis Acids: Boron‐, Silicon‐ and Gallium‐Functionalised Tris(dimethylsilyl)methanes

“…The ethynyl groups of compound 3 are related by a C 3 axis and point away from each other. The C-Si bond lengths in compound 3 have a mean value of 1.859 Å, which compares well with the corresponding values (1.860 [29] and 1.832 Å [30] ) in compounds with Si-C≡C-Si segments previously reported in the literature. [29][30][31][32][33][34] The C≡C triple bonds exhibit a length of 1.208(3) Å [C(4)-C(5)], which correlates well with the values of related compounds.…”

“…The C-Si bond lengths in compound 3 have a mean value of 1.859 Å, which compares well with the corresponding values (1.860 [29] and 1.832 Å [30] ) in compounds with Si-C≡C-Si segments previously reported in the literature. [29][30][31][32][33][34] The C≡C triple bonds exhibit a length of 1.208(3) Å [C(4)-C(5)], which correlates well with the values of related compounds. [29][30][31][32][33][34] The angles of 3 have no irregularities except for the wide Si and other known molecules with a Si-C≡C-Si segment.…”

“…[29][30][31][32][33][34] The C≡C triple bonds exhibit a length of 1.208(3) Å [C(4)-C(5)], which correlates well with the values of related compounds. [29][30][31][32][33][34] The angles of 3 have no irregularities except for the wide Si and other known molecules with a Si-C≡C-Si segment. [29][30][31][32][33][34] Due to the presence of a trimethylsilyl group in 4 at the central carbon atom [C(1A)], the sum of the angles Si (1) …”

“…[29][30][31][32][33][34] The angles of 3 have no irregularities except for the wide Si and other known molecules with a Si-C≡C-Si segment. [29][30][31][32][33][34] Due to the presence of a trimethylsilyl group in 4 at the central carbon atom [C(1A)], the sum of the angles Si (1) …”

Fourfold Diels–Alder Reaction of Tetraethynylsilane

“…The tetrayne 11 has been functionalized using organometallic fragments to give its dicobalt hexacarbonyl and similar complexes 2a. In addition a number of its derivatives have been studied in detail2b,c while the parent compound 11 has been neglected so far—probably due to the explosive side products from the original syntheses 2d,e…”