Self Assembled Organizations of Thermotropic Amphiphiles in Molecular Electronics (Synthesis, Characterization and Utility)

Abstract

Amphiphilic molecules such as lipids and fatty acids tend to self assemble in micellar organizations when dispersed in aqueous medium. Non-amphiphilic biomolecules having special properties can be incorporated in the matrix of these amphiphiles to achieve molecular level organizates. Alternatively, amphiphilic analogues of desired molecules can be synthesized such that they can exhibit self-assembling properties without affecting their intrinsic special properties. Flavins are strong fluorophores and are known to undergo one/two electron redox reactions. Films made from these molecules can be used to make fluorescent display devices. Amphiphilic analogues of Riboflavin and Flavin Adenine Dinucleotide have been prepared by covalently linking fatty acid chains of varying lengths to native molecule. These molecules have been characterized using NMR, ESR, Optical Spectroscopy, Microscopy, DSC etc. Riboflavin modified with stearate chains was found to possess desirable thermotropic characteristics and self-assembling properties suitable for formation of superior quality films on solid substrates.

Amphiphilic analogue of Protoporphyrin IX is formed by effecting covalent linkage with the lipid Phosphatidylethalnoamine. Metallated (Fe) versions of this amphiphile has been found to self-assemble into mesoscopic structures which exhibit desirable magnetic properties.