Cuerva de Alaiz, CristianCampo Santillana, José AntonioCano Esquivel, María MercedesSanz, JesúsSobrados, IsabelDiez-Gómez, VirginiaRivera Calzada, Alberto CarlosSchmidt, Rainer2024-01-172024-01-172016Cuerva C, Campo JA, Cano M, Sanz J, Sobrados I, Diez-Gómez V, Rivera-Calzada A, Schmidt R. Water-free proton conduction in discotic pyridylpyrazolate-based Pt(II) and Pd(II) metallomesogens. Inorg. Chem. 2016, 55(14), 6995-70020020-166910.1021/acs.inorgchem.6b00728https://hdl.handle.net/20.500.14352/93599In this work we report on water-free proton conductivity in liquid-crystal pyridylpyrazolate-based Pt(II) and Pd(II) complexes [M(pzR(n,n)py)2] (pzR(n,n)py = 3-(3,5-dialkyloxyphenyl)-5-(pyridin-2-yl)pyrazolate, R(n,n) = C6H3(OCnH2n+1)2; n = 4, 12, 16, M = Pd; n = 12, M = Pt) with potential application as electrolyte materials in proton exchange membrane fuel cells. The columnar ordering of the complexes in the liquid-crystalline phase opens nanochannels, which are used for fast proton exchange as detected by impedance spectroscopy and NMR. The NMR spectra indicate that the proton conduction mechanism is associated with a novel C–H···N proton transfer, which persists above the clearing point of the material. The highest conductivity of ∼0.5 μS cm–1 at 180 °C with an activation energy of 1.2 eV is found for the Pt(II) compound in the mesophase. The Pd(II) complexes with different chain length (n = 4, 12, and 16) show lower conductivity but smaller activation energies, in the range of 0.74–0.93 eV.engAttribution-NonCommercial-NoDerivatives 4.0 Internationalhttp://creativecommons.org/licenses/by-nc-nd/4.0/journal article1520-510Xhttps://doi.org/10.1021/acs.inorgchem.6b00728open accessElectrical conductivityInterfacesLiquid crystalsProton conductivityMesostructuresQuímica2303 Química Inorgánica