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

We report the structures and physical properties of new β′-(BEDT-TTF)[Fe(oxalate)]·G salts where A = HO, G = PhCl; A = Rb G = Pyridine. The structure of the PhCl salt is isomorphous with β′-(BEDT-TTF)[(HO)M(oxalate)] with other guest molecules. PhCl is ordered in die hexagonal pockets formed by the [(HO)Fe(oxalate)] 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) [RbFe(oxalate)]·Pyridine where Rb replaces HO. 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)[(HO)M(oxalate) ]·salts with M = Cr, Ga, Fe; G = CHCl , CHClBr, CHBr are also reported. © 2005 Elsevier B.V. All rights reserved