A new proton-conductive copper coordination polymer, (HOC3H6)2dtoaCu (dtoa = dithiooxamide)

A new copper coordination polymer, (HOC3H6)(2)dtoaCu (dtoa = dithiooxamide), was synthesized. The crystal structure is considered to be similar to that of a two-dimensional (2-D) coordination polymer (HOC2H4)(2)dtoaCu. The concentration of water molecules included in this polymer was found by thermogravimetric (TG) analysis to increase with relative humidity (RH) upon the sample preservation. The a.c. conductivity measurements with an impedance analyzer were carried out for (HOC3H6)(2)dtoaCu in order to estimate the proton conductivity (sigmap). The log sigmap was linearly increased from 3.3 x 10(-9) to 2.0 x 10(-6) S cm(-1) with RH from 58 to 100% at 300 K. These facts imply that the proton conduction depends on the quantity of water molecules contained in the polymer.