Structural and physical properties of charge transfer complexes with [M(dto)2] anions (M:Ni,Pt,Cu,Pd, dto:Dithiooxalate)

The structural, electrical and magnetic properties of the charge transfer complexes of [M(dto)2] anion with BEDT-TTF and BEDO-TTF are presented. Three-dimensional (3D) alternating stacks of cation radical dimers and dianion molecules with their molecular planes incline to each other with a variety of dihedral angles are observed in the 2:1 complexes of BEDT-TTF with MNi, Pd, Pt and BEDO-TTF with MNi, Pd. They are electrical insulators (10−3–10−7Scm−1). Singlet-triplet type magnetic behaviors were detected in some of these 2:1 complexes. BEDT-TTF and Pd(dto)2 gave a metallic 4:1 complex (ca. 1Scm−1 at RT), whose crystal structure is similar to the oxalate analogs. Cu(dto)2 gave metallic complexes with BEDT-TTF (σ ?RT=40Scm−1, metallic down to 140K) and BEDO-TTF (σ RT=200Scm−1, metallic down to 4K).