Quantum chemical study of the Fe(III)-desferrioxamine B siderophore complex—Electronic structure, vibrational frequencies, and equilibrium Fe-isotope fractionation

Calculation of boron-isotope fractionation between B(OH)3(aq) and

“…This issue is probably most important for anionic and neutral systems. Predicted fractionations in cationic systems, such as Fe 2+ /Fe 3+ appear, thus far, to be less sensitive to the choice of basis set and exchange-correlation functional (Jarzecki et al, 2004;Anbar et al, 2005;Hill and Schauble, 2008;Domagal-Goldman and Kubicki, 2008;Domagal-Goldman et al, 2009;Rustad and Dixon, 2009), although in terms of the percent variation in the total fractionation (10 3 lna), the uncertainties in this system are similar to the iron system.…”

Theoretical and experimental investigation of nickel isotopic fractionation in species relevant to modern and ancient oceans

“…1& (6.046& at 298 K). It should be noted that, in studies on Fe isotope fractionation, some difficulties to reproduce experimental data from theoretical calculations have been reported (Anbar et al, 2005;Domagal-Goldman et al, 2008;Hill et al, 2009). It is of interest that, for trivalent cations like Fe 3+ , a larger cluster model including second coordination shell brings calculation data closer to the experimental results (Li et al, 1996).…”

Density functional theory predictions of equilibrium isotope fractionation of iron due to redox changes and organic complexation

“…We will therefore base our estimates of frequency-induced inaccuracies on the frequencies from Fe-organic compounds. We discuss the accuracy of vibrational frequency predictions for Fe III ðOxÞ 3 3À and Fe III ðCatÞ 3 3À above, and report predictions of Fe bound to the siderophore desferrioxamine B (Fe-DFO-B) in another study (Domagal-Goldman et al, 2008). We use model predictions of frequencies for all three Fe-organic complexes in the error analysis presented below.…”