Two Pentasilahousanes Fused Together

Abstract

The organosilicon cluster 1 with two pentasilahousanes fused together was synthesized by the reduction of 1,1,3-trichlorocyclotetrasilane. This reaction involves dimerization and rearrangement of the silicon skeleton. The structure and properties of 1 were studied by X-ray crystallographic and spectroscopic analyses.

Studies on the Detailed Structure of Poly(dimethylsilylene)

“…In order to assign the signals in the 29 Si and 13 C CP/MAS spectra, we calculated chemical shifts by the gauge-independent atomic orbital (GIAO) method at the B3LYP/6-311+G(2d,p) level. Quite recently, we assigned the signals of the 29 Si CP/MAS and solution NMR spectra of organosilicon clusters with GIAO calculations . The GIAO calculations reproduced the signal pattern of the 29 Si NMR spectra, although there is some difference between the observed and calculated chemical shifts.…”

Decasilahexahydrotriquinacene and Decasilaisotwistane: σ Conjugation on a Bowl Surface

“…By curve fitting of these spectra, shoulders at 238, 256, 268, 289, and 318 nm ( 1 ) and at 219, 255, 269, and 292 nm ( 2 ) were analyzed (Figures S4 and S9, Tables S1 and S2). The absorption without clear bands suggests that 1 and 2 have electronic properties of organosilicon clusters . The absorption edges of 1 (ca.…”

Clusterization Effect on the29Si NMR Signal of a Spiro Silicon Atom

“…550 nm with six shoulders at 254, 278, 295, 322, 395, and 493 nm (Figure , Figure S6, and Table S1). Such broad tailing absorption without clear bands is typical of organosilicon clusters. ,, The broad tailing absorption of 3 resembles that of 2 , although it lacks the lowest energy absorption band of 2 at 585 nm due to the π–π* transition. The lowest and second lowest energy absorption bands of 3 at 493 and 395 nm are assignable to the HOMO–LUMO (λ = 494.2 nm, f = 0.0016) and HOMO–LUMO+1 (λ = 418.3 nm, f = 0.0257) transitions, respectively, based on the time-dependent density functional theory (TD-DFT) calculation (Table S4).…”

“…For example, the isolable radical anion of octasilacubane is stabilized by the delocalization of an unpaired electron all over the molecule in contrast with unstable radical anions of small oligosilanes. Some organosilicon clusters have unique bonding and show unprecedented reactions. , Furthermore, large organosilicon clusters show characteristic tailing absorption without clear bands in UV–vis spectra ,, because of closely stacked molecular orbitals. Taking these results into account, other unique properties would be expected.…”