Publications by authors named "A Kartouzian"
Unlocking the hidden dimension: power of chirality in scientific exploration.
Philos Trans A Math Phys Eng Sci
October 2024
Article Synopsis
- Chirality is an important property that describes how objects can have "handedness," like left and right hands, and it affects many areas of science.
- This article discusses how understanding chirality can help scientists solve problems in fields ranging from tiny particles to huge galaxies.
- The author encourages researchers to explore chirality more since it could lead to new materials and solutions for today's technology challenges.
Article Synopsis
- The observed relationship between circular dichroism (CD) and enantiomeric excess (ee) in chiral systems is usually linear, but there are rare cases of negative nonlinear (NN) behavior that are not well understood.
- Researchers found a strong NN CD-ee dependence in polycrystalline thin films of BINOL using advanced techniques like SHG-CD and CD spectroscopy.
- This NN behavior is linked to changes in supramolecular chirality and could enhance the characterization of enantiomeric excess, benefiting sectors like pharmaceuticals and asymmetric catalysis, suggesting many racemate crystals may exhibit similar behavior.
Hybrid perovskite semiconductor materials are predicted to lock chirality into place and encode asymmetry into their electronic states, while softness of their crystal lattice accommodates lattice strain to maintain high crystal quality with low defect densities, necessary for high luminescence yields. We report photoluminescence quantum efficiencies as high as 39% and degrees of circularly polarized photoluminescence of up to 52%, at room temperature, in the chiral layered hybrid lead-halide perovskites (R/S/Rac)-3BrMBAPbI [3BrMBA = 1-(3-bromphenyl)-ethylamine]. Using transient chiroptical spectroscopy, we explain the excellent photoluminescence yields from suppression of nonradiative loss channels and high rates of radiative recombination.
View Article and Find Full Text PDFSize-selected iron oxide nanoclusters are outstanding candidates for technological-oriented applications due to their high efficiency-to-cost ratio. However, despite many theoretical studies, experimental works on their oxidation mechanism are still limited to gas-phase clusters. Herein we investigate the oxidation of graphene-supported size-selected Fe clusters by means of high-resolution X-ray Photoelectron Spectroscopy.
View Article and Find Full Text PDFHybrid organic-inorganic networks that incorporate chiral molecules have attracted great attention due to their potential in semiconductor lighting applications and optical communication. Here, we introduce a chiral organic molecule ()/()-1-cyclohexylethylamine (CHEA) into bismuth-based lead-free structures with an edge-sharing octahedral motif, to synthesize chiral lead-free ()/()-CHEABiBrI crystals and thin films. Using single-crystal X-ray diffraction measurements and density functional theory calculations, we identify crystal and electronic band structures.
View Article and Find Full Text PDF