Single crystalline commensurate metallic assemblages of π-slabs and Cdl2-type layers:: Synthesis and properties of β-(EDT-TTF-l2)2[Pb5/6□1/6l2]3 and β-(EDT-TTF-l2)2[Pb2/3+xAg1/3-2x□xl2]3, x=0.05

The ability of I...I van der Waals interactions to direct the self-assembly of slabs of the radical cation of ethylenedithio-1,2-diiodo-tetrathiafulvalene, EDT-TTF-I-2, and polymeric lead iodide covalent anionic layers is demonstrated by the synthesis of single crystals of beta-(EDT-TTF-I-2)(2)(.+)[(Pb(5/6)square(1/6)I(2))(1/3-)](3), triclinic, P-1, a = 7.7818(8), b = 7.9760(8), c = 19.9668(2) Angstrom, alpha = 82.409(12), beta = 85.964(12), gamma = 61.621 (11)degrees, V = 1080.76(19) Angstrom(3), R1, wR2 = 0.0459, 0.0947; and beta-(EDT-TTF-I-2)(2)(.+)[(Pb(2/3+x)Ag(1/3-2x)square(x)I(2))(1/3-)](3), x approximate to 0.05, triclinic, P-1, a = 7.7744(8), b = 7.9193(8), c = 19.834(2) Angstrom, alpha = 87.189(12), beta = 83.534(12), gamma = 61.602(11)degrees, V = 1067.4(2) Angstrom(3), R1, wR2 = 0.0508, 0.0997. The state-of-the-art, combined microprobe and structural analysis of the metal site vacancies and occupancies patterns reveal a commensurate organic-inorganic interface and point out the importance of halogen...halogen van der Waals interactions to future studies aiming at directing interface topologies. The electronic structure, room-temperature metallic character and metal-insulator transition at ca. 70 K of the two-dimensional organic slabs are retained upon alloying of the inorganic sublattice with monocations. The room-temperature conductivity of the metallic lead-silver alloy is 2 orders of magnitude larger than that of beta-(EDT-TTF-I-2)(2)(.+)[(Pb(5/6)square(1/6)I(2))(1/3-)](3). This calls for the study of materials with diverse alloying patterns with metal cations of different nature and charge.