Absolute Configuration of a Cyclic Dipeptide Reflected in Vibrational Optical Activity: Ab Initio and Experimental Investigation

0377378 - ÚOCHB 2013 RIV US eng J - Článek v odborném periodiku
Li, X. - Hopmann, K. H. - Hudecová, Jana - Stensen, W. - Novotná, J. - Urbanová, M. - Svendsen, J. S. - Bouř, Petr - Ruud, K.
Absolute Configuration of a Cyclic Dipeptide Reflected in Vibrational Optical Activity: Ab Initio and Experimental Investigation.
Journal of Physical Chemistry A. Roč. 116, č. 10 (2012), s. 2554-2563. ISSN 1089-5639. E-ISSN 1520-5215
Grant CEP: GA ČR GAP208/11/0105; GA MŠMT(CZ) LH11033
Grant ostatní: AV ČR(CZ) M200550902
Výzkumný záměr: CEZ:AV0Z40550506
Klíčová slova: cyclic dipeptide * vibrational otpical activity * density functional theory * dispersion * electronic circular dichroism
Kód oboru RIV: CF - Fyzikální chemie a teoretická chemie
Impakt faktor: 2.771, rok: 2012

The ability of Raman optical activity (ROA) and vibrational circular dichroism (VCD) experiments to determine the absolute configuration of chiral molecules with multiple stereogenic centers was explored for four diastereoisomers of a conformationally flexible cyclic dipeptide, cyclo(Arg-Tyr-(OMe)). The reliability of the interpretation depended on the correct description of the molecular conformation, which was found to be strongly affected by intramolecular interactions. In particular, when dispersion corrections were included in the density functional theory calculations, the simulated spectra matched the experimental observations well. Experimental and theoretical ROA and VCD spectra were well correlated for all the absolute configurations (RS, SR, SS, and RR) of protonated cyclo(Arg-Tyr(OMe)). These spectroscopies thus appear useful not only for reliable determination of the absolute configuration and conformation but also in revealing the role of hydrogen bonds and C-R center dot center dot center dot pi interactions in the structure stabilization, which can potentially be used when designing enzyme inhibitors and supramolecular architectures.
Trvalý link: http://hdl.handle.net/11104/0007004