Persilastaffanes: Design, Synthesis, Structure, and Conjugation between Silicon Cages

Abstract

By stepwise catenation of bicyclo[1.1.1]pentasilane units persila[n]staffanes (n=1, 2, and 3) were synthesized as air‐stable colorless crystals. A remarkable red‐shift of the UV/Vis absorption bands with increasing number of bicyclo[1.1.1]pentasilane units suggests remarkable interactions between bridgehead SiSi σ orbitals and between cage SiSi σ orbitals (see picture).

Dismutational and Global‐Minimum Isomers of Heavier 1,4‐Dimetallatetrasilabenzenes of Group 14

“…To our knowledge, the 29 Si NMR chemical shifts assignable to the untethered “propeller blades” of 9 and 11 represent the by far most deshielded 29 Si NMR resonance signals of tetracoordinate silicon atoms in a molecular environment to date. The enhanced reactivity of the hetero‐substituted propellanes 9 and 11 raises interesting prospects for their application in the construction of extended staffane‐type materials,33 a possibility which is currently being investigated in our laboratories.…”

An Organosilicon Cluster with an Octasilacuneane Core: A Missing Silicon Cage Motif

“…[1] Therefore, synthetic studies on organosilicon clusters have been extensively developed. Persilapolyhedranes, [2][3][4] decasilaadamantane, [5] pentasila[1.1.1]propellane, [6] persila[n]staffane (catenated silicon cages), [7] and related siliconoids [8,9] have all been shown to possess unique electronic characteristics owing to developed s conjugation among the caged SiÀSi bonds. Octasilacuneane, a silicon analog of cuneane [10] (pentacyclo[3.3.0.0 2,4 .0 3,7 .0 6,8 ]octane), is a missing saturated silicon cluster motif, but potentially important because octasilacuneane is an isomeric silicon cage of octasilacubane, [4] one of the most well-known silicon polyhedra.…”

Dismutatives und globales Minimumisomer der schwereren 1,4‐Dimetallatetrasilabenzole der Gruppe 14

“…Nach unserem Wissen stellen die 29 Si‐NMR chemischen Verschiebungen der unverbrückten “Propellerblätter” in 9 und 11 die bei Weitem am stärksten entschirmten 29 Si‐NMR‐Signale von vierfach‐koordinierten Siliciumatomen in einer molekularen Umgebung dar. Die erhöhte Reaktivität der heterosubstituierten Propellane 9 und 11 eröffnet interessante Perspektiven bezüglich ihrer Anwendung zum Aufbau ausgedehnter Staffan‐artiger Materialien,33 eine Möglichkeit, die gegenwärtig in unseren Labors untersucht wird.…”