"It sounds foolish to study this element:" Times crossword Number 14,343

COLL 411

Christopher T. G. Knight, School of Chemical Sciences, School of Chemical Sciences, University of Illinois at Urbana-Champaign, 600 S. Mathews Ave, Urbana, IL 61801
The aqueous chemistry of silicon plays a major role in a number of important and topical fields, and dissolved silicon is ubiquitous throughout the hydrosphere. Silicon-29 nuclear magnetic resonance spectroscopy has proved invaluable in determining the structure of the silicate anions present in inorganic aqueous silicate solutions, and has recently played a critical role in elucidating the nature of the silicon containing species found in living systems. In wholly inorganic alkaline solution a series of small, highly condensed silicate anions exist in dynamic equilibrium, the structures of which are critically different from hypothetical zeolite secondary building units. Upon addition of certain common organic molecules such as carbohydrates, organo-silicates are formed. These often contain five and six coordinate silicon sites. Although such a hypervalent organo-silicate has been observed in living diatoms, experiments with higher plants and animals indicate that the primary vehicle for silicon transport in living systems is monosilicic acid.