Hierarchical transfer of chiral information from the molecular to the mesoscopic scale by Langmuir–Blodgett deposition of tetrasteroid-porphyrins. (19th December 2016)

• Record Type: Journal Article
• Authors: Lettieri, Raffaella; Cardová, Lenka; Gatto, Emanuela; Mazzuca, Claudia; Monti, Donato; Palleschi, Antonio; Placidi, Ernesto; Drašar, Pavel; Venanzi, Mariano
• Is Part Of: New journal of chemistry. Volume 41:Number 2(2017)
• Page Start: 639
• Page End: 649
• Publication Date: 2016-12-19
• Subjects: Chemistry -- Periodicals; Chimie -- Périodiques; 540
• DOI: 10.1039/c6nj02947g
• Languages: English
• ISSNs: 1144-0546

Abstract

Abstract : Transfer of chiral information from the molecular level to the mesoscale has been obtained by hierarchical self-assembly of tetrasteroid-porphyrins. Abstract : Chiral mesoscopic structures were obtained by Langmuir–Blodgett (LB) deposition of two tetrasteroid-porphyrins differing by the number of hydroxy groups functionalizing the steroid rings. The morphology of the porphyrin aggregates was characterized by spectroscopy (UV-Vis absorption, steady-state fluorescence, circular dichroism) and microscopy (fluorescence, scanning electrons, atomic force) techniques. Molecular Mechanics calculations were also carried out to analyze the hierarchical self-assembly process leading to the propagation of the structural properties of the tetrasteroid-porphyrin building blocks to the mesoscopic scale of the imaged chiral architectures. It has been found that, while the transfer of chiral information from the molecular to the nanoscale is determined by the winding of the tetrasteroid chains functionalizing the porphyrin scaffold, the morphology of the mesoscopic aggregates (rods or twisted ribbons) is determined by the amphiphilic (rods) or hydrophobic (ribbons) character of the outer surface of the interacting porphyrin nanostructures.