Design and characterization of a polarized coordination polymer of a zinc(II) biphenyldicarboxylate bearing a sulfone group

A novel coordination polymer of zinc(II) biphenyldicarboxylate bearing a sulfone group, [Zn(sbdc)(H₂O)3]·(H2sbdc)· H ₂O (H₂sbdc: sulfone biphenyldicarboxylic acid), has been synthesized. It is composed of a one-dimensional chain structure of alternating Zn(II) cations and sbdc anions. This coordination polymer possesses noncoordinating uncharged acid H₂sbdc existing between the chains with hydrogen-bonding networks. The proton conductivity of [Zn(sbdc)(H ₂O)₃]· (H₂sbdc) · H₂O strongly depended on the relative humidity (RH), being 2.5 x 10^-7 S cm^-1 at 95% RH. The activation energy for proton conductivity was estimated to be 0.32 eV at 95% RH.