Počet záznamů: 1
CH Stretching Region: Computational Modeling of Vibrational Optical Activity
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SYSNO ASEP 0394880 Druh ASEP J - Článek v odborném periodiku Zařazení RIV J - Článek v odborném periodiku Poddruh J Článek ve WOS Název CH Stretching Region: Computational Modeling of Vibrational Optical Activity Tvůrce(i) Hudecová, Jana (UOCHB-X) RID, ORCID
Profant, V. (CZ)
Novotná, P. (CZ)
Baumruk, V. (CZ)
Urbanová, M. (CZ)
Bouř, Petr (UOCHB-X) RID, ORCIDCelkový počet autorů 6 Zdroj.dok. Journal of Chemical Theory and Computation . - : American Chemical Society - ISSN 1549-9618
Roč. 9, č. 7 (2013), s. 3096-3108Poč.str. 13 s. Jazyk dok. eng - angličtina Země vyd. US - Spojené státy americké Klíč. slova density-functional theory ; circular-dichroism spectra ; N-methyl acetamide ; alpha-pinene ; Raman Vědní obor RIV CF - Fyzikální chemie a teoretická chemie CEP GAP208/11/0105 GA ČR - Grantová agentura ČR LH11033 GA MŠMT - Ministerstvo školství, mládeže a tělovýchovy Institucionální podpora UOCHB-X - RVO:61388963 UT WOS 000321793100025 EID SCOPUS 84880016893 DOI 10.1021/ct400285n Anotace Most organic compounds provide vibrational spectra within the CH stretching region, yet the signal is difficult to interpret because of multiple difficulties in experiment and modeling. To better understand various factors involved, the ability of several harmonic and anharmonic computational approaches to describe these vibrations was explored for a-pinene, fenchone, and camphor as test compounds. Raman, Raman optical activity (ROA), infrared absorption (IR), and vibrational circular dichroism (VCD) spectra were measured and compared to quantum chemical computations. Surprisingly, the harmonic vibrational approach reasonably well reproduced the measured spectral patterns, including the vibrational optical activity (VOA). The CH stretching, however, appeared to be more sensitive to the basis set and solvent variations than lower-frequency vibrations. For a higher accuracy in frequencies and spectral shapes, anharmonic corrections were necessary. Accurate harmonic and anharmonic force fields were obtained with the mPW2PLYP double-hybrid functional. A limited vibrational configuration interaction (LVCI) where the CH stretching motion was decoupled from other vibrations provided the best simulated spectra. A balanced harmonic oscillator basis set had to be used, containing also states indirectly interacting with fundamental vibrations. A simpler second-order perturbational approach (PT2) appeared less useful. The modeling provided unprecedented agreement with experimental vibrational frequencies; spectral shapes were reproduced less faithfully. The possibility of ab initio interpretation of the CH, spectral region for relatively large molecules further broadens the application span of vibrational spectroscopy. Pracoviště Ústav organické chemie a biochemie Kontakt asep@uochb.cas.cz ; Kateřina Šperková, Tel.: 232 002 584 ; Jana Procházková, Tel.: 220 183 418 Rok sběru 2014
Počet záznamů: 1