Constructing Highly Conducting Metal-Metal Bonded Solids by Electrocrystallization of [PtII2(RCS2)4] (RCS2- = Dithiocarboxylato, R = Methyl or Ethyl)

Partially oxidized one-dimensional (1 D) Pt-Pt chain compounds [Pt-2(MeCS2)(4)]4ClO(4)center dot 5PhCN (1) and [Pt-2 (EtCS2)(4)](5)(ClO4)(2) (2) were synthesized by electrocrystaillization of diplaptinum(II,II) complexes from different solvents. I and 2 consist of 1 D Pt-Pt chains of stacked Pt-Pt dimers with short interdimer S center dot center dot center dot S contacts. Depending on the number of ClO4- per dimer and their positions, 1 forms a regular stack of Pt-Pt dimers, whereas 2 forms pentamer of dimers in the 1D chain. 1 exhibits high electrical conductivity (4.2-8,0 S cm(-1)) at 300 K and metallic behavior above 125 K. 2 is a semiconductor. I exhibits almost temperature independent magnetic susceptibility (ca. 1.1 x 10(-4) emu mol(-1)) which is attributed to Pauli paramagnetism, whereas the spin degree of freedom in 2 has been lost. Although the basic structures are closely related, they exhibited different solid-state properties that depend on the valence state of the platinum atoms and the periodicity within the 1 D chain.