Adsorption of monocarboxylates at the water/goethite interface: The importance of hydrogen bonding

ATR-FTIR spectroscopic study of the adsorption of desferrioxamine B and aerobactin to the surface of lepidocrocite (γ-FeOOH)

“…With decreasing pH, the spectra showed a significant downshift of the asymmetric m COO À stretch vibrations of aerobactin to 1550 cm À1 as compared to deprotonated aerobactin in solution (1578 cm À1 ) and a slightly higher frequency of the symmetric m COO À stretch vibration (increase by 2 cm À1 ). This feature is consistent with a chelating mode of inner-sphere adsorbed carboxylate groups (Deacon et al, 1985), but spectral shifts due to outersphere complexation by strong ionic hydrogen bonding interactions are also conceivable (Norén and Persson, 2007).…”

“…1). For acid compounds with lower pK a values, such as monocarboxylic acids, the formation of hydrogen bonding interactions at the surface of iron(III) (hydr)oxides is relevant at acidic pH (Norén and Persson, 2007). Eq.…”

“…(1), hydrogen bonding interactions can considerably contribute to the overall anion adsorption. In this context, Norén and Persson (2007) have shown that acetate, benzoate and cyclohexanoate (monocarboxylic acids) adsorb to goethite at acidic pH predominantly by the formation of surface complexes with strong ionic hydrogen bonding interactions. These authors found no indications for the formation of inner-sphere surface complexes.…”

Soil Chemical Insights Provided through Vibrational Spectroscopy

“…Substantial progress has been made in understanding bacterial adhesion processes through the use of model compounds. For example, elucidation of carboxylate binding mechanisms has been facilitated through FTIR experiments examining amino acids (Norén et al, 2008;Parikh et al, 2011;Roddick-Lanzilotta et al, 1998;Roddick-Lanzilotta and McQuillan, 2000) and model carboxylic acids (Boily et al, 2000;Deacon and Phillips, 1980;Ha et al, 2008;Norén and Persson, 2007). In fact, studies by Alcock and coauthors (1976) and later refined by others (Chu et al, 2004;Deacon and Phillips, 1980;Dobson and McQuillan, 1999), demonstrate that carboxyl binding mechanisms can be inferred through the separation differences (Δν) between the asymmetric carboxylate [ν as (COO − Following the spectral interpretations for model carboxylate compounds, there is evidence for carboxyl involvement during adhesion of P. putida to hematite (α-Fe 2 O 3 ) under flow conditions, possibly forming bidentate bridging complexes to the mineral surface [ν s (COO − ) shift from 1400 to 1415 cm −1 ; Δν ≈ 150 cm −1 ], with additional binding interactions through polysaccharides and phosphoryl groups (Ojeda et al, 2008).…”

Influence of size, morphology, surface structure, and aggregation state on reductive dissolution of hematite nanoparticles with ascorbic acid

“…The adsorption behavior of acetate anion (CH 3 COO À ) on goethite (FeOOH) has been studied in detail by Norén and Persson (2007), while acetate on hematite (Fe 2 O 3 ) has not been reported so far. Considering the point of zero charge (PZC) of these two iron oxides (goethite: 9.2 and hematite: 9.5), their adsorption properties for acetate should be similar.…”