Stable Five- and Six-Coordinated Silicate Anions in Aqueous Solution
Stephen D. Kinrade,
1*
Jeffrey W. Del Nin,
1
Andrew S. Schach,
1
Todd A. Sloan,
1
Krista L. Wilson,
1
Christopher T. G. Knight
2
Addition of aliphatic polyols to aqueous silicate solutions is
shown to yield high concentrations of stable polyolate complexes containing five- or six-coordinated silicon. Coordinating polyols require at least four hydroxy groups, two of which must be in threo configuration, and coordinate to silicon via hydroxy
oxygens at chain positions on either side of the threo pair.
The remarkable ease by which these simple sugar-like molecules react to
form hypervalent silicon complexes in aqueous solution supports a
long-standing supposition that such species play a significant role in
the biological uptake and transport of silicon and in mineral
diagenesis.
1 Department of Chemistry, Lakehead University,
955 Oliver Road, Thunder Bay, Ontario, Canada P7B 5E1.
2 School of Chemical Sciences, University of
Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, IL
61801, USA.
*
To whom correspondence should be addressed. E-mail:
Stephen.Kinrade{at}lakeheadu.ca
