Microscopic Structure Of Cu（Ⅱ） Aqueous Solutions And Its Effects On The Trans-membrane Behaviors Of Cu²⁺ Ions

Water is a highly structured liquid substance due to an extensive network of hydrogen bonds, which plays a unique role in the world. When electrolytes dissolve in water, the large electric field around the ions causes the dipolar water molecules to rearrange themselves in the hydration shells, structure of water around the ions differing from that in bulk water. The process and direction of chemical reactions, the conformation of biomacromolecules such as protein, enzyme and nucleic acid are determined by the structure of electrolyte aqueous solutions. It has great significance both theoretically and practically to understand the microstructure of electrolyte solutions.In this dissertation, the influences of electrolytes and their individual cations and anions on the water structure were studied with viscosity measurement, ¹⁷O-NMR and Raman spectra. The effects of freeze-thaw （FT） and magnetic field （MF） on water cluster association have been examined. The microscopic local environment structure of the Cu²⁺ ion in CuCl₂ aqueous solutions and Zn²⁺ ion in Zn（NO₃）₂ aqueous solutions have been investigated by extended X-ray absorption fine structure （EXAFS） spectroscopy. The effects of salt concentration and freeze thaw on the first hydration shell of metal ions have been analyzed. In addition, the human red blood cell was taken as subject to analysis the effects of water cluster structure and microscopic structure of hydrated ions on the trans-membrane behaviors of Cu²⁺ ions.The effects of ZnCl₂、AlCl₃、CrCl₃、CuCl₂ and CuSO4 on association of hydrogen bond in aqueous solutions are promoted. The results indicated that AlCl₃ make the greatest contribution to promote water cluster association, and CrCl₃、CuSO4、ZnCl₂ make less contribution, with CuCl₂ the least. The degree of structure making effects on water association for cations are Al³⁺>Cr³⁺>Zn²⁺>Cu²⁺. The structure breaking effect on water association of Cl- is stronger than that of SO42-. Generally,the more the ionic charge and the smaller the ionic radius, the larger are the effects of those ions on water association.For pure water and electrolyte solutions, plenty of hydrogen bonds will be broken and rerranged in the freezeing and thawing processes so that the conductivities increase, as well as changing in the viscosity after freeze-thaw treatment. The relationships between ¹⁷O-NMR chemical shifts and concentration of CuCl₂ aqueous solutions are linear. It has been seen that for freeze-thaw treated samples, some decreases appeare in the ¹⁷O-NMR chemical shifts and half-height widths. It is found that the static magnetic field caused increasing in the conductivity and decreasing in the viscosity coefficient, which is attributed to the changed in the association of water cluster under magnetic field. Both freeze-thaw treatment and magnetic field influence have memory effects, with a memory time about 8 hours and 50 minutes respectively.The EXAFS results show that Cu²⁺ ions have 3.0⁴.3 oxygen nearest neighbors with the Cu–O distance being 0.192⁰.198nm in its first coordination shell. These structural properties can be ascribed to the Jahn-Teller effect. With increasing salt concentration, the coordination number of Cu²⁺ decreases and the Cu–O distance increases in its first coordination shell. It is found that Zn²⁺ ions have 3.2⁶.8 oxygen nearest neighbors with the Zn–O distance being 0.202⁰.207 nm. In highly concentrated solutions, Zn²⁺ ions hydrated four water molecules in a tetrahedral geometry. Dilution of the Zn（NO₃）₂ aqueous solutions increases the number of water molecules in the first hydration shell of Zn²⁺ to six with their octahedral arrangement. The hydration number in the first hydration shell of metal ions and the degree of thermal disorder increase when the freeze- thaw treatment is operated in CuCl₂ and Zn（NO₃）₂ aqueous solutions.The amount of transmembrane of Cu²⁺ ions are influenced by extracellular concentration, pH and incubation temperature. The transmembrane transport of Cu²⁺ ions accord to the first order kinetic characteristics during the beginning 2 hours. Cu²⁺ ions are taken into human erythrocytes mostly by [Cu（OH）2Cl]-、[Cu（OH）2HCO3]- through anion transport. In addition, Cu²⁺ ions can transmembrane with K+ ions through co-transport system. The accelerating effects of freeze-thaw and magnetic field on transmembrane transport of Cu²⁺ ions are discovered in our research. The uptake amount and the uptake rate of Cu²⁺ ions in human red blood cell increase when FT treatment and MF treatment are operated. The results of SEM show that Cu²⁺ ions could change shapes of normal human erythrocytes. Cu（Ⅱ） did induce some red blood cells lost their normal profile. Even 0.1mmol?L-1 CuCl₂ solution could present a spiny configuration with blebs or protuberances in their surfaces. According to the bilayer couple hypothesis, these shape changes of erythrocytes are due to differential expansion of their two monolayers. The influences of Cu（Ⅱ） on human erythrocytes are more evident when the CuCl₂ aqueous solutions are operated by freeze thaw or magnetic field.