Extended X-ray Absorption Fine Structure of Copper(II) Complexes at the Air-Water Interface by a Polarized Total-Reflection X-ray Absorption Technique (original) (raw)

X-ray absorption near edge studies of some binuclear copper(II) complexes

Journal of Synchrotron Radiation, 2001

It has been found that the chemical shift values are higher in the chlorine adducts as compared to the values of chemical shift reported by us in an earlier work for the parent complexes, showing that the chlorine adducts are more ionic. The observed splitting of the principal absorption maximum (1s→4p) in the chlorine adducts has been explained in terms of the splitting of the metal 4p orbital degeneracy.

X-ray absorption studies of metal complexes in aqueous solution at elevated temperatures

Chemical Geology, 1996

Experimental methods for performing X-ray absorption spectroscopy (XAS) on metal complexes in dilute aqueous solutions at temperatures up to 573 K are presented. The solutions are contained in silica tubes for study by X-rays of energies greater than 16 keV. For experiments using X-rays of energies in the range 6.5-16 keV, we have developed a titanium cell with Kapton windows. These cells can be heated in an aluminium oven up to 573 K. Using these methods we have studied the tetrahedral: octahedral equilibrium for cobalt(II) in aqueous chloride solutions, NazMoO 4 • 2H20 in aqueous solution and cadmium(II) in aqueous chloride solutions. For cobalt(II) in chloride concentrations between 5 and 7 m we have found evidence that [COC14] 2-is not the only important tetrahedral species. In molybdate(VI) solutions, [MOO4] 2is the predominant species over the temperature range 298-573 K. Cadmium(II) in aqueous chloride solutions shows two major cadmium complexes [Cd(OH2)6] 2+ and [CdC14] 2-. Bond distances for the principal species in these solutions are presented and are found to be in general agreement with those obtained from X-ray crystallographic studies on related solids.

In situ X-ray absorption study of copper films in ground water solutions

Chemical Physics Letters, 2007

This study illustrates how the damage from copper corrosion can be reduced by modifying the chemistry of the copper surface environment. The surface modification of oxidized copper films induced by chemical reaction with Cl À and HCO À 3 in aqueous solutions was monitored by in situ X-ray absorption spectroscopy. The results show that corrosion of copper can be significantly reduced by adding even a small amount of sodium bicarbonate. The studied copper films corroded quickly in chloride solutions, whereas the same solution containing 1.1 mM HCO À 3 prevented or slowed down the corrosion processes.