HYDROGEN-BONDING .54. NMR-STUDY OF THE EFFECTS OF ANESTHETICS ON HYDRATION OF CHOLINE, ACETYLCHOLINE AND TETRAETHYLAMMONIUM HALIDES IN AQUEOUS-SOLUTION

The onset and development of N-14 to C-H coupling on sequential diluti on of saturated solutions of the chloride and bromide salts of choline , acetylcholine and tetraethylammonium cations were used to determine the effect of the anesthetic substances chloroform, methane, argon and diethyl ether on the formation of primary and secondary hydration str uctures. The addition of anesthetics tends to reduce the number of H2O molecules required to form the primary structure. Anesthetics reduce the number of H2O molecules in the secondary structures of salts that form secondary structures in the absence of anesthetics, and promote t he formation of secondary structures for salts that do not form second ary structures in the absence of anesthetics. These phenomena are disc ussed in terms of competition between salt and anesthetic substance as structure formers. Anesthetics appear to disrupt the ''iceberg'' wate r of hydration of acetylcholine; this effect might play some role in t heir action in anesthesia.