A Ternary Crown Ether “Supercomplex”: X‐Ray Structure Analysis of the 1:1:1 Adduct of Dibenzo‐[18]‐Crown‐6, Potassium Iodide, and Thiourea

For the formation of ternary “super complexes” the character of the participating anions is of decisive importance. In the polymeric 1:1:1 complexes of dibenzo‐18‐crown‐6, potassium iodide, and thiourea, K⁺ is situated in the center of the crown ether cavity and is additionally coordinated by I⁻; thiourea forms polymeric chains linked by H‐bridges. Only readily polarizable ions such as I ⁻ are capable of functioning as connecting links between crown ether complexes and thiourea chain.