Organo-mineral complex structure

Emerson WW, Foster RC, Oades JM (1986) Organo-mineral complexes in relation to soil aggregation and structure. In Huang PM, Schnitzer M (eds) Interactions of soil minerals with natural organics and microbes. Soil Sci Soc Am, Madison, WI, USA, pp 521-548... 

NMR can provide detail regarding the types of NOM structures that are preferentially sorbed to mineral surfaces in soils and sediments. Simpson et al. (2006b) used H liquid-state and HR-MAS NMR methods to study the sorption of model compound mixtures to calcium-saturated montmorillonite. The model compound mixture included one representative compound from each of the following structural classes sugars, lignin, peptides, and long-chain aliphatics. After sorption, the supernatant was analyzed by liquid-state NMR and the organo-mineral complex... 

S. Yariv and K.H. Michaelian, Structure and Surface Acidity of Clay Minerals. In Organo-Clay Complexes and Interactions, ed. S. Yariv and H. Cross, Marcel Dekker, New York, 2002. 

The only detailed information available on the structures of organo-clays is from studies of vermiculite and kaolinite complexes. Unfortunately, smectites do not form three-dimensionally ordered structures. For the organo-smectites, it is possible to roughly determine the orientation of the molecules in the interlayer space based on the dimensions of the molecules, assumptions as to how the molecules are attached to the clay smface and measured increases in the interlayer spacing compared to the untreated clay mineral. In certain c lses it is possible to calculate the X-ray diffraction intensities for model structrues and compare these with measured values. For example, Reynolds (1965) showed that the ethylene glycol molecule is oriented with the symmetry plane of the molecule oriented normal to the clay layer and coordinating the interlayer Ca ions in a structure with only one-dimensional... 

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