Partial Halogenation of Cyclic and Branched Perhydropentasilanes

Abstract

The perhydropentasilanes (H(3)Si)(4)Si and Si(5)H(10) were chlorinated with SnCl(4) to give chlorohydropentasilanes without destruction of the Si-Si backbone. Tetrachloroneopentasilane (ClH(2)Si)(4)Si (2) was prepared in high yield from (H(3)Si)(4)Si and 3.5 equiv of SnCl(4), while Si(5)H(10) and an equimolar amount of SnCl(4) afforded a mixture of ∼60% of ClSi(5)H(9) (1) with polychlorinated cyclopentasilanes and unreacted starting material, which could not be separated by distillation. The selective monochlorination of Si(5)H(10) was achieved starting from MesSi(5)Cl(9) (3; Mes = 2,4,6-trimethylphenyl) or TBDMP-Si(5)Cl(9) (4; TBDMP = 4-tert-butyl-2,6-dimethylphenyl). 3 or 4 was successfully hydrogenated with LiAlH(4) to give MesSi(5)H(9) (6) or TBDMP-Si(5)H(9) (7), which finally gave 1 along with aryl-H and Si(5)H(10) after treatment with an excess of liquid anhydrous HCl. All compounds were characterized by standard spectroscopic techniques. For Si-H derivatives, the coupled (29)Si NMR spectra were analyzed in detail to obtain an unequivocal structural assignment. The molecular structures of 2-4 were further confirmed by X-ray crystallography.

Cleavage of the Silicon-Silicon and Silicon-Chlorine Bond oftBu3Si-SiCl3

“…This structural motif was first described by Choi et al . Generally, these chlorosilicates can be easily transformed with LiAlH 4 into the corresponding silanes . However, the major disadvantage is that air‐sensitive Si 2 Cl 6 is needed as a starting material for this approach.…”

Extremely bulky secondary phosphinoamines as substituents for sterically hindered aminosilanes

“…To date, only mono-aryl substituted cyclic, five-membered chlorosilanes have been structurally characterized, 22 and other related five-membered cyclic silianes were obtained by different synthetic approaches. 27 The molecular structures of 11 and 12 were successfully determined by single crystal XRD (Fig.…”

Tetrel Bonding Interactions

“…Remarkably, Si···N distances (2.95–3.04 Å) are significantly shorter than the sum of their van der Waals radii (3.65 Å), but longer than the sum of their covalent radii (1.88 Å). Moreover, Stueger et al . have synthesized and X‐ray characterized a cyclopentasilane derivative (see Figure B), where one aromatic side group (mesityl) is attached to the ring.…”