Silanones

Silanones are a class of inorganic compounds with the general formula R2Si=O, where R represents hydrogen or an organic group. They are characterized by a silicon-oxygen double bond, analogous to the carbonyl group (C=O) found in organic ketones. However, the silicon-oxygen double bond is significantly different in character from the carbon-oxygen double bond. While the carbon-oxygen double bond is a true double bond involving a pi bond, the silicon-oxygen double bond is often described as having a significant degree of polarity and a degree of double bond character arising from pi-backbonding from oxygen's lone pairs into silicon's empty d-orbitals. This pi-backbonding plays a crucial role in stabilizing the Si=O linkage.

Silanones are generally highly reactive species. They readily undergo polymerization, often forming polysiloxanes, which are the backbone of silicone materials. This polymerization can occur rapidly upon generation of the silanone. Due to their instability, isolated silanones are typically only observed in the gas phase or at very low temperatures, often as transient intermediates in reactions. Their study provides insights into the fundamental bonding and reactivity of silicon-oxygen systems. Research into silanones is important for understanding the formation of silicones and for developing new silicon-containing materials.