Reactions of potassium iodomercurate(II) with crown ethers and cryptands: Crystal structures of bis[di(benzo-15-crown-5)potassium]-, di[(benzo-18-crown-6)potassium]-, di[(cryptand 221)potassium]-, and di[(cryptand 222)potassium] hexaiododimercurate (II)

The reactions of potassium iodomercurate(II) with the crown ethers benzo-15-crown-5, and benzo-18-crown-6, resp. as well as with the cryptands 221 and 222 were investigated. In all cases only the potassium ion was complexed. As anions only hexaiododimercurate(II) ions were formed but no higher oligomers. If the complexed potassium ion is not completely shielded by the ligand, further coordination by terminal iodine atoms of the mercurate anions takes place, leading to the formation of dimers or chains.