1. Helicity-Dependent Regiodifferentiation in the Excited-State Quenching and Chiroptical Properties of Inward/Outward Helical Coumarins.
- Author
-
Mukhopadhyay A, Hossen T, Ghosh I, Koner AL, Nau WM, Sahu K, and Moorthy JN
- Subjects
- Circular Dichroism, Coumarins chemical synthesis, Electron Transport, Hydrogen Bonding, Molecular Conformation, Quantum Theory, Solvents chemistry, Spectrophotometry, Stereoisomerism, Coumarins chemistry
- Abstract
Influence of helicity on the excited-state as well as chiroptical properties of two sets of regiohelical coumarins that are differentiated by "inward" and "outward" disposition of the pyran-2-one ring has been investigated. A subtle difference in the helicities manifests in divergent excited-state properties and significant differences in the dipole moments. The latter permit heretofore unprecedented regiodifferentiation in the O-H⋅⋅⋅O hydrogen-bond assisted electron-transfer quenching by phenols. Furthermore, the enantiopure hexahelical coumarins exhibit strong Cotton effects and lend themselves to a very high differentiation in the specific rotations and anisotropic dissymmetry factors. The specific rotation observed for 6-in turns out being the highest of the values reported for all hexahelicenes reported so far., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2017
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