Disilane-bridged architectures: an emerging class of molecular materials

Disilanes are organosilicon compounds that contain saturated Si–Si bonds. The structural characteristics of Si–Si single bonds resemble those of C–C single bonds, but their electronic structure is more similar to that of C[double bond, length as m-dash]C double bonds, as Si–Si bonds have a higher HOMO energy level. These organosilicon compounds feature unique intramolecular σ electron delocalization, low ionization potentials, polarizable electronic structure, and σ–π interaction. It has been demonstrated that the employment of disilane units (Si–Si) is a versatile and effective approach for finely adjusting the photophysical properties of organic materials in both solution and solid states. In this review, we present and discuss the structure, properties, and relationships of novel σ–π-conjugated hybrid architectures with saturated Si–Si σ bonds. The application of disilane-bridged σ-conjugated compounds as optoelectronic materials, multifunctional solid-state emitters, CPL, and non-linear optical and stimuli-responsive materials is also reviewed.