Selective Synthesis of New Hexaalkylbicyclo[1.1.1]pentasilanes with Improved Solubility

Molecular structures and properties of molecular silicon clusters and oligo/polysilanes depend on the substituents on the silicon skeletons. Herein, we report the synthesis of new bicyclo[1.1.1]pentasilanes (BPS) having various alkyl substituents (ethyl, iBu, or 2‐ethylbutyl) at the bridge silicon atoms. All new BPS are characterized by NMR spectroscopy, MS spectrometry, and single crystal X‐ray diffraction (sc‐XRD) analysis. Introduction of longer alkyl groups and unsymmetrical substitution of alkyl groups at the bridge positions on the BPS skeleton substantially improve the solubility toward organic solvents, while the electronic properties are similar to each other.