Ion pairing in H2O and D2O solutions of lead nitrate, as determined with Pb-207 NMR spectroscopy


Alkan F. , Small T., Bai S., Dominowski A., Dybowski C.

JOURNAL OF STRUCTURAL CHEMISTRY, vol.57, no.2, pp.369-375, 2016 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 57 Issue: 2
  • Publication Date: 2016
  • Doi Number: 10.1134/s0022476616020189
  • Title of Journal : JOURNAL OF STRUCTURAL CHEMISTRY
  • Page Numbers: pp.369-375
  • Keywords: lead nitrate, contact-ion pair, equilibrium, exchange, NMR spectroscopy, CHEMICAL-SHIFT, AQUEOUS-SOLUTIONS, THERMODYNAMICS, APPROXIMATION, SALTS, WATER, DISSOCIATION, RELAXATION, DEPENDENCE, HYDRATION

Abstract

The temperature and concentration dependences of Pb-207 NMR chemical shifts of Pb(NO3)(2) in D2O are reported. The results are analyzed in terms of exchange between a solvated lead ion and the Pb(NO3)(+) contact-ion pair. Predictions of the chemical shift difference between the aquated ion and contact-ion pair are carried out for the gas-phase entities and for the solvated species with a DFT calculation. Previously reported data on Pb-207 NMR chemical shifts of Pb(NO3)(2) in H2O are reevaluated. From the analysis, the enthalpy of dissociation of the contact-ion pair is found to be-42.3 +/- 1.0 kJ/mol.