A strongly twisted SiSi bond with resemblance to a buckled dimer in an unexpected isomer of hexasilabenzene

Synthesis and functionalization of the six-vertex anionic amido-substituted silicon cluster [Si6{N(SiMe3)Ph}5]. Dalton Trans 2023;52:14949-14955. [PMID: 37800884 DOI: 10.1039/d2dt03952d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

The reaction of the six-vertex amido-substituted silicon cluster Si6{N(SiMe3)Ph}6 1 with two equiv. of KC8 results in the abstraction of K{N(SiMe3)Ph} and leads to the contact ion pair 2 including an anionic silicon cluster with two unsubstituted pyramidal vertices. Facile functionalization of 2 was achieved with MeI, SiCl4 and SiBr4 and results in neutral two-fold functionalized silicon clusters.

Stable Silapyramidanes

Starting from tetrakis(trimethylsilyl)cyclobutadiene and an amidinate-supported silylene of the Roesky-type, a sequence of addition and reduction cleanly gives the elusive silapyramidane via an isolable cyclobutene intermediate with an exocyclic Si═C bond. The silapyramidane features an unusually shielded ²⁹Si NMR resonance at -448.3 ppm for the apex silicon atom. Treatment with Fe₂(CO)₉ results in the formation of the corresponding silapyramidane-iron complex. Silapyramidane also reacts with the cyclobutadiene starting material to cleanly afford a fluorescent spirobis(silole).

Twisted push–pull disilenes obtained by direct 1,2-hydro/chloroborylation of a silylone

Twisted 1-amino-2-boryl disilenes which feature highly polarized SiSi bonds were synthesized by the direct hydro/chloroborylation of a silylene-stabilized monatomic silicon complex.