Figure 6
(a)/(b) The 51V NMR spectra of the crystallization solution of VMo7 and (c)/(d)/(e) solutions obtained upon dissolution of crystallized VMo7 at different pH values. Conditions: (a) 175 mM MoVI, 25 mM VV, pH = 3.1, 24 h after the synthesis; (b) same conditions as (a) after another 24 h; (c)/(d)/(e) 10 mM VV solution prepared from VMo7 by dissolving it in 0.5 mM NaCl at pH values of (c) 4.0, (d) 5.2 and (e) 6.0. The pH was adjusted by the addition of a dilute KOH solution. |