Metal coordination as a tool for controlling the self-assembling and gelation properties of novel type cholic amide-phenanthroline gelating agent

(3alpha,7alpha,12alpha)-Trihydroxy-N-[1,10-phenanthrolin-5-yl]-5beta-cholan-24-amide was found to be a powerful gelating agent for methanol-water in gelator to solvent ratio starting from 0.1% in absence of metal ion. Formation of phenanthroline-zinc (II) 2:1 complex changes dramatically gelating properties; when stored, it dissolves into clear solution without Tyndall effect and this solution, when heated to ca. 70degreesC reversibly forms a gel again, without chemical change as proven by NMR spectrometry. Structures of the gels of cholic amide-phenanthroline and its Zn2+ complex were studied by SEM. (C) 2003 Elsevier Science Ltd. All rights reserved.