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An Inherently Chiral Au 24 Framework with Double‐Helical Hexagold Strands
Author(s) -
Sugiuchi Mizuho,
Shichibu Yukatsu,
Konishi Katsuaki
Publication year - 2018
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201804087
Subject(s) - chirality (physics) , diphosphines , crystallography , square antiprism , helicene , enantiomer , chemistry , circular dichroism , steric effects , stereochemistry , physics , lanthanide , molecule , symmetry breaking , catalysis , chiral symmetry breaking , biochemistry , organic chemistry , quantum mechanics , nambu–jona lasinio model , ion
2,3‐bis(diphenylphosphino)butane enantiomers (chiraphos, L) used as chiral auxiliaries results in the preferential formation of an unprecedented Au 24 framework with inherent chirality. The crystal structure of [Au 24 L 6 Cl 4 ] 2+ ( 1 ) has a square antiprism‐like octagold core twinned by two helicene‐like hexagold motifs, where the inherent chirality is associated with the helical arrangement. The clusters carrying ( R , R )‐ and ( S , S )‐ diphosphines had right‐ and left‐handed strands, respectively. Circular dichroism spectra showed peaks in the visible to near‐IR region, some of which did not coincide with absorption bands, suggesting the enantiomeric Au 24 frameworks possess unique chiroptical properties. The Au 24 frameworks were thermally robust, which could be attributed to the superatomic concept (18 e − system) and the steric constraint effects of the bridging ligand units.