On the structure of amorphous calcium carbonate--a detailed study by solid-state NMR spectroscopy.
The calcium carbonate phases calcite, aragonite, vaterite, monohydrocalcite (calcium carbonate monohydrate), and ikaite (calcium carbonate hexahydrate) were studied by solid-state NMR spectroscopy ( (1)H and (13)C). Further model compounds were sodium hydrogencarbonate, potassium hydrogencarbonate, and calcium hydroxide. With the help of these data, the structure of synthetically prepared additive-free amorphous calcium carbonate (ACC) was analyzed. ACC contains molecular water (as H 2O), a small amount of mobile hydroxide, and no hydrogencarbonate. This supports the concept of ACC as a transient precursor in the formation of calcium carbonate biominerals.
Nebel
Holger
H
Inorganic Chemistry, University of Duisburg-Essen, Universitaetsstr. 5-7, 45117 Essen, Germany.
Neumann
Markus
M
Mayer
Christian
C
Epple
Matthias
M
D002119:Calcium Carbonate / Q000737:chemistry*; D002126:Calcium Hydroxide / Q000737:chemistry; D002245:Carbon Dioxide / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D013055:Spectrophotometry, Infrared; D014961:X-Ray Diffraction
D002245:Carbon Dioxide; D002119:Calcium Carbonate; D002126:Calcium Hydroxide