Metallic Bi‐ and Monolayered Radical Cation Salts Based on Bis(ethylenedithio)­tetrathiafulvalene (BEDT‐TTF) with the Tris(oxalato)gallate Anion

New metallic triclinic (1) and monoclinic (2) crystals of the (BEDT-TTF)(4)A(I)[M-III(C2O4)(3)]G family of organic molecular conductors have been prepared: alpha-"pseudo-kappa"-(BEDT-TTF)(4)K-x(H3O)(1-x)[Ga-III(C2O4)(3)]center dot 1,2-C6H4Br2 (x approximate to 0.45) (1) and beta "-(BEDT-TTF)(4)K-x(H3O)(1-x)[Ga-III(C2O4)(3)]center dot PhBr (x approximate to 0.33) (2). The triclinic crystals belong to a quite rare type of bilayered radical ion salts and contain alternating BEDT-TTF layers with two distinct packing motifs (alpha- and "pseudo-kappa"). The monoclinic crystals contain one kind of BEDT-TTF radical cation layers. The crystal structure, transport, and magnetotransport properties of 1 and 2 have been studied. The Shubnikovde Haas (SdH) oscillations were found in both phases. The structure and properties of 1 and 2 are compared with another similar phase with M = Fe-III.