Structures and physical properties of new β′-BEDT-TTF tris-oxalatometallate (III) salts containing chlorobenzene and halomethane guest molecules

Abstract We report the structures and physical properties of new β ′-(BEDT-TTF) 4 [Fe(oxalate) 3 ]·G salts where A = H 3 O + , G = PhCl; A = Rb + G = Pyridine. The structure of the PhCl salt is isomorphous with β ′-(BEDT-TTF) 4 [(H 3 O)M(oxalate) 3 ] with other guest molecules. PhCl is ordered in die hexagonal pockets formed by the [(H 3 O)Fe(oxalate) 3 ] layer. The electrical conductivity is metallic down to 100 K, below which the resistivity increases with decreasing temperature. The specific conductivity at room temperature is about 10 S/cm. We also report the salt β ′-(BEDT-TTF) 4 [RbFe(oxalate) 3 ]·Pyridine where Rb + replaces H 3 O. The electrical resistivity shows metallic behavior down to 100 K. and turns up gradually to a maximum at 65 K below which the system re-enters the metallic state down to liquid helium temperature. Neither salt shows superconductivity down to 2 K. In addition, other new β ′-(BEDT-TTF) 4 [(H 3 O)M(oxalate) 3 ]·salts with M = Cr, Ga, Fe; G = CH 2 Cl 2 , CH 2 ClBr, CH 2 Br 2 are also reported.