A step closer to the binary: the 1∞[Bi6I20]2− anion

Abstract

A series of crown ether based iodidobismuthates was prepared from dibenzo-18-crown-6 (DB18C6), BiI₃ and NaI or KI in acetonitrile (MeCN). The resulting compounds [(DB18C6)Na(MeCN)₂]₄[Bi₆I₂₂]·2MeCN (1), [(DB18C6)Na(MeCN)₂]₄[Bi₈I₂₈]·6MeCN (2), [(DB18C6)Na(MeCN)₂]₂[Bi₆I₂₀]·3MeCN (3) and [(DB18C6)K(MeCN)]₄[Bi₆I₂₂]·2MeCN (4) have been used to explore the templating effect of different crown ether based cations and the influence of the I/Bi ratio and I⋯I interactions on the optical properties of iodidobismuthates. Compound 3 contains the strand-like anion ¹_∞[Bi₆I₂₀]²⁻, which displays a I/Bi ratio of 3.33, closer to the binary BiI₃ than any other iodidobismuthate.