| Abstract
| - Twelve indole derivatives have been prepared and studied. Five were 1-substituted: 1, methyl; 2,n-hexyl; 3, n-octyl; 4, n-octadecyl; and 5, cholestanyloxycarbonylmethyl. Four were 3-substituted: 6, methyl; 7, n-hexyl; 8, n-octyl; and 9, n-octadecyl. Three were disubstituted as follows: 10, 1-n-decyl-3- n-decyl; 11, 1-methyl-3-n-decyl; and 12, 1,3-bis(n-octadecyl)indole. Sonication of aqueoussuspensions afforded stable aggregates from 3−5 and 8−12. Laser light scattering, dye entrapment,and electron microscopy were used to characterize the aggregates. Aggregates formed fromN-substituted indoles proved to be more robust than those formed from 3-alkylindoles. A stablemonolayer formed from 3-n-octadecylindole but not from N- or 1,3-disubstituted analogues by usinga Langmuir−Blodgett trough. The formation of aggregates was explained in terms of stacking bythe relatively polar indole headgroup. In the monolayer experiment, this force was apparentlyoverwhelmed by H-bonding interactions with the aqueous phase.
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