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

• Published in: Tetrahedron 2003-06, Vol.59 (23), p.4069-4076
• Main Authors: Dukh, M., Šaman, D., Kroulı́k, J., Černý, I., Pouzar, V., Král, V., Drašar, P.
• Format: Article
• Language: English
• Subjects: assembling; cholic acid; gels; NMR; phenanthroline
• ISSN: 0040-4020; 1464-5416
• DOI: 10.1016/S0040-4020(03)00587-8

(3α,7α,12α)-Trihydroxy- N-[1,10-phenanthrolin-5-yl]-5β-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. 70°C reversibly forms a gel again, without chemical change as proven by NMR spectrometry. Structures of the gels of cholic amide–phenanthroline and its Zn 2+ complex were studied by SEM. Steroid–phenanthroline conjugate was found to be a powerful gelating agent for methanol–water. Formation of phenanthroline–zinc (II) 2:1 complex changes the gelating properties; when stored, it dissolves into solution and this solution, when heated reversibly forms a gel again. Complexes and gels were studied by spectroscopic methods and SEM.