Abstract
When two benzene rings are fused to a tetraaryl-o-quinodimethane skeleton, sterically hindered helical molecules 1 acquire a high thermodynamic stability. Because the tetraarylbutadiene subunit contains electron-donating alkoxy groups, 1 undergo reversible two-electron oxidation to 22+, which can be isolated as deeply colored stable salts. Intramolecular transfer of the point chirality (e.g., sec-butyl) on the aryl groups to helicity induces a diastereomeric preference in dications 2 b2+ and 2 c2+, which represents an efficient method for enhancing circular-dichroism signals. Thus, those redox pairs can serve as new electrochiroptical response systems. X-ray analysis of dication 22+ revealed π-π stacking interaction of the diarylmethylium moieties, which is also present in solution. The stacking geometry is the key contributor to the chirosolvatochromic response.
Original language | English |
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Pages (from-to) | 117-123 |
Number of pages | 7 |
Journal | Chemistry - A European Journal |
Volume | 19 |
Issue number | 1 |
DOIs | |
Publication status | Published - 2013 Jan 2 |
Externally published | Yes |
Keywords
- chirality
- circular dichroism
- electrochromism
- helical structures
- redox chemistry
ASJC Scopus subject areas
- Catalysis
- Organic Chemistry