Silicon Caught Carbon Copying Wolff–Kishner Reduction in Two Dimensional Siloxene Nanosheets

Abstract

Despite vast potential, silicon chemistry has taken a back foot in the recent past as compared to its counterpart, carbon. Recently, silicon-based inorganic compounds containing silicon and oxygen have attracted significant attention. Of these, one intriguing nanostructure is Siloxene, a 2D oxide of silicon. Its close structural resemblance to 2D carbon compounds provides an opportunity to explore chemistries similar to carbon in silicon. Here, we have investigated the stability and reduction of Si═O bonds in 2D-Siloxene using hydrazine in potassium hydroxide. The reduction of 2D Siloxene shows striking similarity to Wolff–Kishner reduction, which is well-known in carbon chemistry. Specifically, the polarization of the Si═O bond in Siloxene results in charge separation between the silicon and oxygen atoms. This significantly enhances the reactivity of the Si═O bond and renders it susceptible to reduction. Mulliken charge analysis within the framework of density functional theory calculations suggests the electronegative behavior of O atoms, when attached to Si both as Si═O and Si–OH. The electropositive Si atom in Si═O is attacked by hydrazine hydrate, subsequently, when treated with a strong base, typically potassium hydroxide, affects the reduction of the hydrazone. Our study provides strong theoretical and experimental evidence for a reduction mechanism analogous to the Wolff–Kishner reduction, in 2D silicon, enabling developing insights in silicon reduction.