Stable five- and six-coordinated silicate anions in aqueous solution

Area of Science:

• Chemistry
• Biochemistry
• Geology

Background:

• Silicon is essential in biological systems and geological processes.
• Understanding silicon's aqueous chemistry is crucial for various scientific fields.

Purpose of the Study:

• To investigate the formation of stable silicon-polyol complexes in aqueous solutions.
• To explore the role of polyols in silicon coordination chemistry.

Main Methods:

• Aqueous silicate solutions were reacted with aliphatic polyols.
• Characterization of the resulting polyolate complexes was performed.

Main Results:

• High concentrations of stable five- or six-coordinated silicon-polyolate complexes were formed.
• Polyols with at least four hydroxyl groups, including a threo configuration, effectively coordinated with silicon.
• Coordination occurred via hydroxyl oxygens adjacent to the threo pair.

Conclusions:

• Aliphatic polyols readily form hypervalent silicon complexes in water.
• These complexes likely play a key role in biological silicon transport and mineral diagenesis.