Molecular conductors based on radical cation hydrated halides: new crystal phase of the (BEDT-TTF)3Br2·2H2O organic metal

A new crystal phase of the (BEDT-TTF)3Br2·2H2O radical cation salt was characterized by single crystal X-ray diffraction, electrical resistivity measurements at ambient and high pressures and electronic band structure calculations. (BEDT-TTF)3Br2·2H2O is triclinic with space group P1 (a=11.225(2) Å, b=13.964(3) Å, c=16.141(3) Å, α=94.48(3)°, β=109.01(3)°, γ=97.08(3)°, V=2354.8(8) Å3, Z=2). The salt is similar to the corresponding chloride salt in its donor molecular packing motif and electronic structure but differs in its transport properties.