Distinguishing different surface interactions for nucleotides adsorbed onto hematite and goethite particle surfaces through ATR-FTIR spectroscopy and DFT calculations
Izaac Sit, Mark A. Young, James D. Kubicki, Vicki H. Grassian
Abstract
) for each mineral surface yet are distinctly different between the two minerals, suggesting differences in binding of these nucleotides to the two mineral surfaces. The experimental absorption frequencies in the phosphate region were compared to DFT calculations for nucleotides adsorbed through the phosphate group to binuclear clusters in either a monodentate or bidentate bridging coordination. Although the quality of the fits suggests that both binding modes may be present, the relative amounts differ on the two surfaces with preferential bonding suggested to be monodentate coordination on hematite and bidentate bridging on goethite. Possible reasons for these differences are discussed.