Raman and infra-red spectral studies of the aqueous zinc(II)-nitrite system

Raman and infra-red spectra obtained from aqueous solutions containing zinc(II) and nitrite ions indicate that nitrite ions displace water molecules from the coordination sphere of the hexaquozinc(II) cation. Graphical and numerical analyses of quantitative Raman measurements suggest step-wise formation of the mono- and di-nitrite complexes with equilibrium constants K1= 1.4 and K2= 0.9 at 25°C.