Proton conduction through the nanochannel water in weak-acidic nanoporous crystals [Cu2(phen)2(AcO)2(H2O)2][Al(OH)6Mo6O18]M+(nH2O) (M+ = H+, Li+, Na+, K+)

Hiroshi Matsui, Makoto Tadokoro

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)


In the weak-acidic nanoporous crystals of [Cu2(phen)2(AcO)2(H2O)2][Al(OH)6Mo6O18]M+(nH2O) (M+ = H+, Li+, Na+, K+; M-salt), the microwave conductivity measured by a cavity perturbation technique without electric contacts reveals an activation-type temperature change and isotope effect. The proton conduction through the water network strongly depends on the type and configuration of alkaline-metallic ions intercalated into the hydrophilic nanochannel with a square cross section. The water network with Na+ configured close to the framework molecule in Na-salt is soft in comparison with Li- and K-salts, in which Li+ and K+ situate near the center of nanochannel, and the whole hydrogen bonds are strengthened. From the infrared spectra, an Eigen-type hydrated proton is found to dominate the proton conduction. As for H-salt with the highest proton conductivity and the softest nature among the four salts, a Zundel-type hydrated proton makes also significant contribution for the proton conduction in addition to the Eigen-type hydrated proton.

Original languageEnglish
Pages (from-to)165-169
Number of pages5
JournalSolid State Ionics
Publication statusPublished - 2016 Feb 1


  • Alkaline metal
  • Hydrate
  • Nanochannel
  • Proton conduction
  • Water

ASJC Scopus subject areas

  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics


Dive into the research topics of 'Proton conduction through the nanochannel water in weak-acidic nanoporous crystals [Cu<sub>2</sub>(phen)<sub>2</sub>(AcO)<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>][Al(OH)<sub>6</sub>Mo<sub>6</sub>O<sub>18</sub>]M<sup>+</sup>(nH<sub>2</sub>O) (M<sup>+</sup> = H<sup>+</sup>, Li<sup>+</sup>, Na<sup>+</sup>, K<sup>+</sup>)'. Together they form a unique fingerprint.

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