Proton conduction in a nonporous one dimensional coordination polymer

Complex impedance measurements on single crystals and pellets of a CuCo-orotate coordination polymer, as a function of relative humidity and temperature, reveal proton conduction with a relatively high thermal activation energy, a negligible isotope effect, a large pre-exponential factor in the conductivity model, and a strong dependence on humidity, all of which are consistent with a vehicle mechanism. The proton conductivity found for this polymer compares favorably with that of MOFs and related porous materials even though it has no framework with pores and channels to provide proton-conduction pathways.We acknowledge support from grants MAT2012-38213-C02-01 and MAT2011-27233-C02-01 from the Ministerio de Economía y Competividad of Spain and the European Regional Development Fund. Additional support from Diputación General de Aragón (DGA-CAMRADS, DGA-M4) is also acknowledged. E.F.V. thanks the Ministry of Education (Spain) for a predoctoral scholarship under the program “Becas y Contratos FPU” (reference AP2009-4211). The authors acknowledge the use of Servicio General de Apoyo a la Investigación-SAI, Universidad de Zaragoza.Peer reviewe