Ab initio investigation on ion-associated species and association process in aqueous Na2SO4 and Na2SO4/MgSO4 solutions

作者：Zhang, Hao^*; Wang, Song; Sun, Chia-Chung

来源：Journal of Chemical Physics, 2011, 135(8): 084309.

DOI：10.1063/1.3622859

• MAGNESIUM-SULFATE SOLUTIONS
• FOLGE CHEMISCHER RELAXATION
• OUTER-SPHERE COMPLEXES
• HYGROSCOPIC PROPERTIES
• RAMAN-SPECTROSCOPY
• VIBRATIONAL ANALYSIS
• PAIR FORMATION
• INNER-SPHERE
• HYDRATION
• SODIUM

In the present paper, the possible ion associated species in pure Na2SO4 and mixed Na2SO4/MgSO4 aqueous solutions are investigated via the ab initio method at the HF/6-31+G* level. The vibrational nu(1)-SO42- band is analyzed. For the unhydrated species, when the number of metal ions around the SO42- ion is less than 3, the dominating effect to the nu(1)-SO42- band is the polarization of the cations, while the M-O bonding will be dominating as the number is equal to or more than 3. For the hydrated species, the coordinated structures of the Na+ ion in all ion pairs are not stable due to the strong effect of the SO42- ion but relatively stable in the triple ion (TI) clusters since there are fewer vacant hydration sites around the SO42-. The nu(1)-SO42- frequencies are close to that of the hydrated SO42- ion in the ion pairs and larger in both Na2SO4 and Na2SO4/MgSO4 TI clusters. On the basis of our calculated results, the evolvement of Raman spectra in the Na2SO4/MgSO4 droplet with the molar ratio of 1:1 is explained.

• 出版日期2011-8-28
• 单位吉林大学