Infrared and Raman spectroscopic and theoretical studies of hexaaqua metal ions in aqueous solution

Oxidative scavenging of thallium by birnessite: Explanation for thallium enrichment and stable isotope fractionation in marine ferromanganese precipitates

“…As discussed above, the first-shell coordination geometry of hydrated Tl(I) is weak and irregular. On the other hand, hydrated Tl(III) is reported as 6-fold coordinated (Tl(H 2 O) 6 3+ (Mink et al, 2003). Our Tl XANES results indicate predominantly Tl(III)-sorbed Hx-birnessite after 2 h and 336 h contact time.…”

A Lennard-Jones plus Coulomb potential for Al3+ ions in aqueous solutions

“…Using a model devised to treat the ͓Al͑H 2 O͒ 6 ͔ 3+ complex as a supramolecular species, Martínez et al 21 report these two bands near 400 and 550 cm −1 , in good agreement with experimental bending ͑E g ͒ and symmetric stretching ͑A 1g ͒ modes at 438 and 525 cm −1 , respectively. 25,54 Our model overestimates the bending mode frequency by ϳ5% and significantly overestimates the stretching. In this respect, the model of Martinez et al captures the experimental symmetric stretching ͑525 cm −1 ͒ much better than our simple potential and even multibody potentials derived on the basis of ab initio quantum potential energy surface calculations.…”

Role of nuclear volume in driving equilibrium stable isotope fractionation of mercury, thallium, and other very heavy elements

“…For mercury and thallium these criteria appear to correspond to $1 · 10 À8 hartree (%3 · 10 À2 J/mol) accuracy in calculated electronic energies, equivalent to approximately 0.01& in a calculated fractionation factor at 298 K. The complete open shell configuration interaction (COSCI) method is used to Janz and James, 1963 shown in parentheses). a 56 cm À1 frequency is calculated by Mink et al (2003) based on a fitted force field. b Several higher-frequency Hg-and Tl-isotope sensitive modes in XðH 2 OÞ 6 nþ complexes have not been measured, so ab initio frequencies and frequency ratios are used-potential errors are addressed in the Appendix A.…”