# Silicon‐Based Azo Compound‐Mediated CO Activation and N2 Release

## TL;DR

Scientists created a new silicon-based azo compound that can activate carbon monoxide and release nitrogen gas, showcasing silicon's potential in complex chemical reactions.

## Contribution

The synthesis of a thermally stable silicon-based azo compound with Si─N═N─Si linkage and its ability to mediate CO activation and N2 release is novel.

## Key findings

- A silicon-based azo compound was synthesized from a silaiminyl–silylene precursor and an azide.
- The compound activates CO, cleaves the C≡O bond, and releases N2, forming a Si(II)/Si(IV) product.
- The transformation incorporates carbon into a byproduct and allows coordination with Fe(CO)4 fragments.

## Abstract

Silicon‐substituted azo compounds featuring Si─N═N─Si linkages remain elusive in main‐group chemistry. Herein, we report the synthesis of a silicon‐based azo compound generated directly from a mixed‐valent silaiminyl–silylene precursor and a bulky organic azide. Unlike classical iminosilane formation, this reaction affords a thermally stable Si(IV)–azo species. Upon treatment with carbon monoxide (CO), this compound undergoes N2 extrusion, complete C≡O bond cleavage, and formation of a formal Si(II)/Si(IV) product in which an oxygen atom bridges both silicon centers. Notably, the transformation incorporates the carbon atom into a DippNC byproduct via ligand rearrangement. A similar transformation occurs upon reaction with Fe(CO)5, wherein N2 release and CO cleavage also occur, but with the resulting Fe(CO)4 fragment coordinating to the silicon center. These results demonstrate a rare example of silicon based azo‐mediated small‐molecule activation and highlight the potential of silicon‐based systems for multi‐electron redox chemistry typically associated with transition metals.

A rare silicon(IV)‐based azo compound featuring a Si─N═N─Si linkage was synthesized via the direct reaction of an organoazide with a silaiminyl–silylene precursor. This compound undergoes an unusual CO activation process, resulting in N2 release and complete cleavage of the C≡O bond, forming a Si(II)/Si(IV) product bridged by an oxygen atom and an organic isonitrile.