Silicon-29 NMR studies of aqueous silicate solutions. 1. Chemical shifts and equilibria

Journal Article · Wed Nov 16 04:00:00 EST 1988 · Inorg. Chem.; (United States)

DOI:https://doi.org/10.1021/ic00296a034· OSTI ID:5974314

Kinrade, S D; Swaddle, T W

In the /sup 29/Si NMR spectra of aqueous alkali-metal (M) silicate solutions ((MOH):(Si/sup IV/) = 1.0 or higher), variations in solution composition cause displacements of the peaks of up to 1 ppm largely through interaction of silicate units with M/sup +/. The analysis of the chemical shift data provides a means of predicting /sup 29/Si resonance frequencies for new silicate species and has aided in the identification of the Si/sub 4/O/sub 10//sup 4/minus// (Q/sub 4//sup 3/) anion, in which the Si atoms are at the corners of a regular tetrahedron. A quantitative study of the dependence of silicate connectivity upon temperature (-5 to +144 /degree/C) and solution composition shows that silicate polymerization is favored by low temperature, low alkalinity, and high (Si/sup IV/). In no case could silicate centers with 4-fold connectivity (Q/sup 4/) be detected. The effect of M/sup +/ on the distributions of silica species is small, but the larger M/sup +/ atoms do preferentially stabilize the more highly polymerized silicate anions. 35 refs., 8 figs., 3 tabs.

• Research Organization: Univ. of Calgary, Alberta (Canada)
• OSTI ID: 5974314
• Journal Information: Inorg. Chem.; (United States), Journal Name: Inorg. Chem.; (United States) Vol. 27:23; ISSN INOCA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
400202 -- Isotope Effects
Isotope Exchange
& Isotope Separation
ALKALI METAL COMPOUNDS
CHEMICAL SHIFT
DATA
EVEN-ODD NUCLEI
EXPERIMENTAL DATA
INFORMATION
ISOTOPES
LIGHT NUCLEI
MOLECULAR STRUCTURE
NMR SPECTRA
NUCLEI
NUMERICAL DATA
OXYGEN COMPOUNDS
SILICATES
SILICON 29
SILICON COMPOUNDS
SILICON ISOTOPES
SPECTRA
STABLE ISOTOPES