Studies of helical aggregates of molecules. II. The sense of twist in the fibrous aggregates from the Alkali metal soaps of optically active 12-hydroxystearic acid

Abstract

Under an electron microscope, it was observed that the alkali metal soaps of 12-D(or L)-hydroxystearic acid separated out twisted fibers from various solutions. A symmetrical relationship regarding the sense of the twist was found between the soap fibers of the D-enantiomer and those of the L-enantiomer. In the case of the soap fibers of the D-enantiomer, the sense of twist was right-handed for the Li soap and left-handed for the Rb and Cs soaps. The Na- and the K- soap fibers produced both right-handed and left-handed fibers. A solvent effect with respect to the sense of twist was found for the fibers of the free acid and its Li soap. The cause of the twisting was discussed in connection with the structure and the growth process of the soap crystal.