Baciu, Bianca C., Bronk, Pawel Jaroslaw, Ara, Tamara de, Rodríguez, Rafael, Morgante, Pierpaolo, Vanthuyne, Nicolas, Sabater, Carlos, Untiedt, Carlos, Autschbach, Jochen, Crassous, Jeanne, Guijarro, Albert
Dithia[9]helicenes: Molecular design, surface imaging, and circularly polarized luminescence with enhanced dissymmetry factors
Journal of Materials Chemistry C. 2022, 10: 14306-14318. https://doi.org/10.1039/D2TC02910C
URI: http://hdl.handle.net/10045/126704
DOI: 10.1039/D2TC02910C
ISSN: 2050-7526 (Print)
Abstract: 
We have carried out the synthesis of two dithia[9]helicenes by means of a LED-based double photocyclization. The compounds have sulfur atoms placed at the terminal rings of the helicene, and they display two alternative C2-symmetrical arrangements named exo (1) and endo (2). Separation of enantiomers of opposite helicity allowed the complete characterization of their chiroptical properties in solution, in silico, by X-ray crystallography, and adsorbed on gold. The theoretical analysis confirms the unexpected finding that endo-dithia[9]helicene displays an experimental dissymmetry factor in CPL (glum) larger than its isomer, exo-dithia[9]helicene. This enhanced glum factor ranks among the largest for a helicene-type molecule. Comparison with smaller analogues, namely exo and endo-dithia[7]helicenes (10 and 11, respectively), is also presented.
Keywords:Dithia[9]helicenes, Molecular design, Surface imaging, Circularly polarized luminescence, Enhanced dissymmetry factors
Royal Society of Chemistry
info:eu-repo/semantics/article