Chemistry of a 1,5-Oligosilanylene Dianion Containing a Disiloxane Unit

Abstract

Synthesis of a number of disiloxane containing cyclo- and bicyclooligosilanes is described starting from the dipotassium 1,5-oligosiloxanylene diide derived from 1,3-bis[tris(trimethylsilyl)silyl]tetramethyldisiloxane. In addition, the use of this particular fragment as ligand for zinc and group 4 metallocene complexes was studied. Both types of compounds exhibit marked structural differences compared to related compounds containing Si-Si-Si units instead of the Si-O-Si fragment.

Rare-Earth–Silyl ate-Complexes Opening a Door to Selective Manipulations

“…The chemical shift of the resonance clearly indicates a very high degree of polarity of the Si–Y interaction, which is only slightly less polar than the respective magnesium compound [(DME)·Mg{Si(SiMe 3 ) 2 SiMe 2 } 2 O] (δ 29 Si = −166.7 ppm). 16 Such strong silanide character was neither observed for Tilley’s Cp* 2 YSiH(SiMe 3 ) 2 (δ 29 Si = −120.0 ppm, 1 J Si–Y = 92 Hz) 9 nor for Piers’ R(Me 3 Si) 2 SiYI 2 ·(THF) 3 (R = SiMe 3 : δ 29 Si = −134.7 ppm, 1 J Si–Y = 63 Hz; R = Et: δ 29 Si = −73.5 ppm, 1 J Si–Y = 71 Hz), 21 both of which are neutral complexes. The expected higher degree of covalent Si–Y interaction for the neutral compounds is nicely reflected by their larger 1 J Si–Y coupling constants.…”

“…For this reason, we treated 2Y with Cp 2 ZrCl 2 and obtained 1-zircona-4-oxatetrasilacyclohexane 3 ( Scheme 2 ), which had been prepared previously in the reaction of 1 with Cp 2 ZrCl 2 . 16 Another reaction of 2Y with InCl 3 gave the respective cyclic indium compound, 4 ( Scheme 2 ). Previously, it had been shown that the reactions of oligosilanylene diides with InCl 3 and GaCl 3 lead to formation of cyclic dichloroindate or -gallate complexes.…”

“…Observed NMR data were found to be in accordance with reported literature values. 16 …”

Siloxane Coordination Revisited: Si−O Bond Character, Reactivity and Magnificent Molecular Shapes

“…This is similar to the aforementioned silanolates. Complexes obtained in this way involve the cations Li + , [82–86] Na + , [87–89] K + , [85,87,89–91] Rb + , [89] Cs + , [87,89,92] Mg 2+ , [93] Sr 2+ , [94] Ba 2+ , [95,96] Sn 4+ , [97,98] Cr 2+/3+ , [99,100] Fe 3+ , [101] Y 3+ , [100,102] Zr 4+ , [103] Sm 2+ , [104] Tm 3+ , [105] Yb 2+ , [104,106–108] Th 4+ , [109–112] U 4+ , [109–113] and UO 2 2+ [114] . Hence, many siloxane⋅⋅⋅M n+ contacts might have been established over the years but are rather occasionally than purposefully realized.…”

A 1,5-Oligosilanylene Dianion as Building Block for Oligosiloxane Containing Cages, Ferrocenophanes, and Cyclic Germylenes and Stannylenes

“…The resulting building block is represented by the easily available disiloxane 1. Its treatment with two equivalents of t BuOK leads to the respective oligosilanylene diide 2 (Scheme 1) [11], which can be used as a versatile starting material for the preparation of larger molecular architectures containing oligosiloxane substructures [15].…”