A novel oxalate-based three-dimensional coordination polymer showing magnetic ordering and high proton conductivity

作者:Mon Marta; Vallejo Julia; Pasan Jorge; Fabelo Oscar; Train Cyrille*; Verdaguer Michel; Ohkoshi Shin ichi; Tokoro Hiroko; Nakagawa Kosuke; Pardo Emilio
来源:Dalton Transactions, 2017, 46(43): 15130-15137.
DOI:10.1039/c7dt03415f

摘要

A novel three-dimensional (3D) coordination polymer with the formula (C3N2H5)(4)[MnCr2(ox)(6)]center dot 5H(2)O (2), where ox = oxalate and C3N2H5 = imidazolium cation, is reported. Single crystal X-ray diffraction reveals that this porous coordination polymer adopts a chiral three-dimensional quartz-like architecture, with the guest imidazolium cations and water molecules being hosted in its pores. This novel multifunctional material exhibits both a ferromagnetic ordering at T-C = 3.0 K, related to the host MnCr2 network, and high proton conductivity [1.86 x 10(-3) S cm(-1) at 295 K and 88% relative humidity (RH)] due to the presence of the acidic imidazolium cations and free water molecules. The similarity of the structure of compound 2 to that of the previously reported analogous compound (NH4)(4)[MnCr2(ox)(6)]center dot 4H(2)O, (1), also allows us to analyse, to a certain extent, the effect of the acidity of the proton donating guest molecules on proton conduction properties. 2 hosts, in one-dimensional (1D) channels, imidazolium cations, which are more acidic than the ammonium ones in 1 and, as a consequence, 2 shows higher proton conduction than 1, highlighting the effect of the pK(a) of the proton donating guest molecules on proton conductivity.

  • 出版日期2017-11-21