Characterization Of Molecular Arrangement Of Long-Chain Ferrocenyl Derivatives Having Asymmetric Carbon By Method Of Organized Molecular Films And Formation Of Its Helical Nanofibers

Formation of organized molecular film and helical nanofibers of ferrocene derivatives having R-12-hydroxystearyl chains with asymmetric carbon was investigated. The 12-hydroxystearyl chain, which induces "thixotropy" due to the formation and breakage of intermolecular hydrogen bonds, was introduced into the ferrocenyl unit. The structure of this derivative as a monolayer on the water surface and its Langmuir-Blodgett (LB) film properties were analyzed. The monolayer showed a two-dimensional phase transition, corresponding to the formation of fibrous morphology. In the LB multilayers, intermolecular hydrogen bonding between hydroxyl groups at the 12-position of the chain and crystalline packing was observed. Raman mapping revealed the difference in surface morphology of each derivative depending on the number of 12-hydroxystearyl chains. The derivative having the single chain showed a right-handed helical morphology in the film and this behavior is similar to those having two and three chains. In circular dichroism spectra, the film showed a positive Cotton effect. Since the helical chains easily entangle with each other to form a sponge-like organization, it was expected that the solvent uptake was the origin of gelation induction to its contact solvent.