Internal dynamics in helical molecules studied by X-ray diffraction, NMR spectroscopy and DFT calculations

0474961 - ÚOCHB 2018 RIV GB eng J - Journal Article
Dračínský, Martin - Storch, Jan - Církva, Vladimír - Císařová, I. - Sýkora, Jan
Internal dynamics in helical molecules studied by X-ray diffraction, NMR spectroscopy and DFT calculations.
Physical Chemistry Chemical Physics. Roč. 19, č. 4 (2017), s. 2900-2907. ISSN 1463-9076. E-ISSN 1463-9084
R&D Projects: GA ČR GA15-11223S; GA ČR GA15-12719S
Institutional support: RVO:61388963 ; RVO:67985858
Keywords : helicene * NMR spectroscopy * DFT calculations
OECD category: Physical chemistry; Physical chemistry (UCHP-M)
Impact factor: 3.906, year: 2017
http://pubs.rsc.org/en/content/articlehtml/2013/cp/c6cp07552e

The conformational behaviour of a prototype helical molecule, [6] helicene, and its derivatives was studied in solution and the solid state. Available crystal structures of [6] helicene revealed surprisingly large flexibility of this molecule and variable-temperature NMR experiments provided unusual temperature dependence of chemical shifts of hydrogen, carbon and fluorine atoms in the peripheral aromatic rings of [6] helicene and tetrafluoro[6] helicene. These chemical shift changes were interpreted as a consequence of the helicene 'pitch' opening with elevated temperature, and the experimental data were corroborated by DFT calculations of the chemical shift dependence on the helicene conformation and by variable-temperature DFT molecular dynamics simulations.
Permanent Link: http://hdl.handle.net/11104/0271854