Single Crystalline Commensurate Metallic Assemblages of π-slabs and CdI₂-Type Layers: Synthesis and Properties of β-(EDT-TTF-I₂)₂[Pb_5/6_1/6I₂]₃ and β-(EDT-TTF-I₂)₂[Pb_2/3+<i>_x</i>Ag_1/3-2<i>_x</i><i>_x</i>I₂]₃, <i>x</i> = 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-I2, and polymeric lead iodide covalent anionic layers is demonstrated by the synthesis of single crystals of β-(EDT-TTF-I2)2•+[(Pb5/6□1/6I2)1/3-]3, triclinic, P-1, a = 7.7818(8), b = 7.9760(8), c = 19.9668(2) Å, α = 82.409(12), β = 85.964(12), γ = 61.621(11)°, V = 1080.76(19) Å3, R1, wR2 = 0.0459, 0.0947; and β-(EDT-TTF-I2)2•+[(Pb2/3+xAg1/3-2x□x I2)1/3-]3, x ≈ 0.05, triclinic, P-1, a = 7.7744(8), b = 7.9193(8), c = 19.834(2) Å, α = 87.189(12), β = 83.534(12), γ = 61.602(11)°, V = 1067.4(2) Å3, 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 β-(EDT-TTF-I2)2•+[(Pb5/6□1/6I2)1/3-]3. This calls for the study of materials with diverse alloying patterns with metal cations of different nature and charge.本工作通过合成两种单晶——β-(EDT-TTF-I₂)₂•+[(Pb₅/₆□₁/₆I₂)₁/₃⁻]₃与β-(EDT-TTF-I₂)₂•+[(Pb₂/₃₊ₓAg₁/₃₋₂ₓ□ₓI₂)₁/₃⁻]₃，证实了范德华相互作用（van der Waals interactions）可引导乙二硫基-1,2-二碘四硫富瓦烯（ethylenedithio-1,2-diiodo-tetrathiafulvalene，缩写EDT-TTF-I₂）自由基阳离子片层与聚合碘化铅共价阴离子层的自组装过程。其中前者为三斜晶系，空间群P-1，晶胞参数a=7.7818(8) Å、b=7.9760(8) Å、c=19.9668(2) Å，α=82.409(12)°、β=85.964(12)°、γ=61.621(11)°，晶胞体积V=1080.76(19) ų，最终精修因子R₁=0.0459、wR₂=0.0947；后者x≈0.05，同样为三斜晶系、空间群P-1，晶胞参数a=7.7744(8) Å、b=7.9193(8) Å、c=19.834(2) Å，α=87.189(12)°、β=83.534(12)°、γ=61.602(11)°，晶胞体积V=1067.4(2) ų，精修因子R₁=0.0508、wR₂=0.0997。借助最先进的微探针与结构分析技术，对金属位点的空位与占有率分布进行解析后发现，该体系存在共格的有机-无机界面，同时揭示了卤素-卤素范德华相互作用对于未来调控界面拓扑结构的研究具有重要指导意义。该二维有机片层的电子结构、室温金属性以及约70 K处的金属-绝缘体转变特性，在无机亚晶格与单阳离子发生合金化后得以保留。这种铅银合金体系的室温电导率比β-(EDT-TTF-I₂)₂•+[(Pb₅/₆□₁/₆I₂)₁/₃⁻]₃高出两个数量级。这一结果呼吁后续开展针对不同性质与电荷的金属阳离子的多样化合金化模式的材料研究。