Preparation and properties of the new one-dimensional conductor, partially-oxidized calcium bis(oxalato)platinate

Abstract

A new metal chain compound, Ca 0.756[Pt(C 2O 4) 2]·3H 2O, was prepared electrochemically and found to have a triclinic lattice and an average Pt-Pt separation of 2.889 ± 0.01 rA. It was also found to have a room-temperature conductivity of 2.4 – 12.1 S/cm and a temperature dependence similar to that of a one-dimensional (1-D) complex such as KCP (Br). The interchain coupling constant was estimated as 0.029 using the Horovitz equation, and it was proved to be the smallest among the compounds in this series (which were shown to have stronger interchain interaction than partially oxidized tetracyanoplatinates). Interchain interaction was also discussed in relation to Braude's classification of the isostructural partially-oxidized bis(oxalato)platinates with divalent cations. The ratio of the three-dimensional ordering temperature to the Peierls transition temperature, T 3D/ T P, was found to be a convenient indicator for the magnitude of the interchain interaction in 1-D metal chain conductors.