Water structure at the air-aqueous interface of divalent cation and nitrate solutions.

The water surface structure of aqueous magnesium, calcium, and strontium nitrate solutions with six to seven water molecules on average solvating each ion was investigated using vibrational sum frequency generation (VSFG) spectroscopy. Raman (polarized) and infrared spectroscopies were used for understanding solvation effects. Infrared reflection spectra were analyzed to further understand the VSFG data.