Anisotropic semiconduction in single crystals of dichlorodiamminepalladium(II)–tetrachlorodiamminepalladium(IV) and related halogen-bridged mixed-valence complexes

Abstract

Single crystals of the mixed-valence halogen-bridged complexes [Pd^II(NH₃)₂Cl₂,Pd^IV(NH₃)₂Cl₄] and [Pd^II(NH₃)₂-Cl₂,Pt^IV(NH₃)₂Cl₄] exhibit anisotropic semiconducting properties with the highest conductivity in the direction of the –M^II–Cl–M^IV– chains. Conduction in the chain direction is reported for some similar complexes, and the bonding within the chains is discussed. A description is given of the apparatus developed to measure the conductivities σ_‖ and σ_⊥ of small crystals.