Isolated pentaiodide anions in [K(18-crown-6)]I(5)

Acta Crystallogr C. 2003 Oct;59(Pt 10):M427-8. doi: 10.1107/s010827010301953x. Epub 2003 Sep 30.

Abstract

(1,4,7,10,13,16-Hexaoxacyclooctadecane-kappa(6)O)potassium pentaiodide, [K(C(12)H(24)O(6))]I(5), obtained by slow evaporation of an ethanol solution of KI, 18-crown-6 and I(2), contains [K(18-crown-6)](+) cations (C(i) symmetry) and I(5)(-) anions (C(2) symmetry), which are arranged in alternating layers parallel to (001). In contrast to the well known tendency of I(5)(-) ions to form chains and nets, the I(5)(-) units in the title compound are isolated.