Silver Iodobismuthates: Syntheses, Structures, Properties, and Theoretical Studies of [Bi₂Ag₂I₁₀^2-]<i>_n</i> and [Bi₄Ag₂I₁₆^2-]<i>_n</i>

Two novel silver iodobismuthates have been obtained: (Et4N)2n-[Bi2Ag2I10]n (1) with one-dimensional infinite chains built from bimetallic tetranuclear units and (Et4N)2n[Bi4Ag2I16]n (2) with a two-dimensional 44 grid assembly of the tetranuclear Bi4I16 subunits as nodes and Ag atoms as linkages. Their optical band gaps, 2.05 and 1.93 eV, fit nicely in a size correlation of the Bi/I subunit, which is further supported by the density functional theory studies.