125239-74-9 4',4''-Bis(trimethylammonium)dibenzo-18-crown-6 diiodide Dibenzo(b,k)(1,4,7,10,13,16)hexaoxacyclooctadecin-2,14-diaminium, 6,7,9,10,17,18,20,21-octahydro-N,N,N,N',N',N'-hexamethyl-, diiodide