Synthesis of 2,2,3,3‐Tetraphenyl‐5,5,6,6,7,7,8,8‐octamethyl‐2,3,5,6,7,8‐hexasilabicyclo[2.2.2]octane – a Phenyl‐substituted Silicon‐containing Cage

Abstract

Molecular cages that contain silicon are highly versatile and stable materials with great potential for various scientific and technological applications due to their ability to form stable three‐dimensional frameworks. The synthesis of 2,2,3,3,5,5,6,6,7,7,8,8‐dodecamethyl‐2,3,5,6,7,8‐hexasilabicyclo[2.2.2]octane has already been reported and its modifications at the CH moiety have been demonstrated to afford varied functionality. Here, we present the synthesis and characterization of 2,2,3,3‐tetraphenyl‐5,5,6,6,7,7,8,8‐octamethyl‐2,3,5,6,7,8‐hexasilabicyclo[2.2.2]octane, which is a phenyl‐substituted analogue of such a silicon‐containing cage. The Ph‐substituted Si‐containing cage exhibits a low‐lying LUMO due to the hyper‐conjugation including Si–Si, Si–C σ*‐orbitals, and π(phenyl)‐orbitals, which results in a remarkable bathochromic shift in the UV‐vis absorption spectrum.