An Experimental Determination of the Inter-Nitrogen Distance in Some Bis-Quaternary Ammonium Ganglionic and Neuromuscular Blocking Agents

Abstract

The conductances in water of hexamethonium bromide and iodide, decamethonium bromide and iodide, hexadecamethonium iodide, and decaethonium iodide have been measured. The values of the limiting cationic conductances have been interpreted in terms of molecular shape, and the internitrogen distance for the above compounds calculated, using hydrodynamic relationships. The internitrogen distances found were 6·3 Å for hexamethonium, 9·5 Å for decamethonium, 13·5 Å for hexadecamethonium, and 10·2–13·5 Å for decaethonium. The effect of the hydrocarbon/water interfacial energy on the extended lengths of these molecules is discussed.