Abstract
Rotational barrier energy studies to date have focused on the amide bond of aromatic compounds from a kinetic perspective using quantum calculations and nuclear magnetic resonance (NMR). These studies provide valuable information, not only regarding the basic conformational properties of amide bonds but also the molecular gear system, which has recently gained interest. Thus, we investigate the precise motion of the amide bonds of two aromatic compounds using an experimental rotational barrier energy estimation by NMR experiments and a theoretical evaluation of the density functional theory calculation. The theoretical potential energy surface scan method combined with the quadratic synchronous transit 3 method and consideration of additional functional group rotation with optimization and frequency calculations support the results of the variable temperature1H NMR, with deviations of less than 1 kcal/mol. This detailed experimental and theoretical research strongly supports molecular gear motion in the aromatic amide system, and the difference in kinetic energy indicates that the electronic effect from the aromatic structure has a key role in conformational movements at different temperatures. Our study provides an enhanced basis for future amide structural dynamics research.
| Original language | English |
|---|---|
| Article number | 2294 |
| Journal | Molecules |
| Volume | 23 |
| Issue number | 9 |
| DOIs | |
| Publication status | Published - 2018 Sep 8 |
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Keywords
- Amide bond
- Density functional theory
- Kinetic
- Nuclear magnetic resonance
- Rotational barrier energy
ASJC Scopus subject areas
- Analytical Chemistry
- Chemistry (miscellaneous)
- Molecular Medicine
- Pharmaceutical Science
- Drug Discovery
- Physical and Theoretical Chemistry
- Organic Chemistry
Cite this
Electronic effect on the molecular motion of aromatic amides : Combined studies using VT-NMR and quantum calculations. / Kim, Sungsoo; Kim, Jungyu; Kim, Jieun; Won, Daeun; Chang, Suk Kyu; Cha, Wansik; Jeong, Keunhong; Ahn, Sangdoo; Kwak, Kyungwon.
In: Molecules, Vol. 23, No. 9, 2294, 08.09.2018.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Electronic effect on the molecular motion of aromatic amides
T2 - Combined studies using VT-NMR and quantum calculations
AU - Kim, Sungsoo
AU - Kim, Jungyu
AU - Kim, Jieun
AU - Won, Daeun
AU - Chang, Suk Kyu
AU - Cha, Wansik
AU - Jeong, Keunhong
AU - Ahn, Sangdoo
AU - Kwak, Kyungwon
PY - 2018/9/8
Y1 - 2018/9/8
N2 - Rotational barrier energy studies to date have focused on the amide bond of aromatic compounds from a kinetic perspective using quantum calculations and nuclear magnetic resonance (NMR). These studies provide valuable information, not only regarding the basic conformational properties of amide bonds but also the molecular gear system, which has recently gained interest. Thus, we investigate the precise motion of the amide bonds of two aromatic compounds using an experimental rotational barrier energy estimation by NMR experiments and a theoretical evaluation of the density functional theory calculation. The theoretical potential energy surface scan method combined with the quadratic synchronous transit 3 method and consideration of additional functional group rotation with optimization and frequency calculations support the results of the variable temperature1H NMR, with deviations of less than 1 kcal/mol. This detailed experimental and theoretical research strongly supports molecular gear motion in the aromatic amide system, and the difference in kinetic energy indicates that the electronic effect from the aromatic structure has a key role in conformational movements at different temperatures. Our study provides an enhanced basis for future amide structural dynamics research.
AB - Rotational barrier energy studies to date have focused on the amide bond of aromatic compounds from a kinetic perspective using quantum calculations and nuclear magnetic resonance (NMR). These studies provide valuable information, not only regarding the basic conformational properties of amide bonds but also the molecular gear system, which has recently gained interest. Thus, we investigate the precise motion of the amide bonds of two aromatic compounds using an experimental rotational barrier energy estimation by NMR experiments and a theoretical evaluation of the density functional theory calculation. The theoretical potential energy surface scan method combined with the quadratic synchronous transit 3 method and consideration of additional functional group rotation with optimization and frequency calculations support the results of the variable temperature1H NMR, with deviations of less than 1 kcal/mol. This detailed experimental and theoretical research strongly supports molecular gear motion in the aromatic amide system, and the difference in kinetic energy indicates that the electronic effect from the aromatic structure has a key role in conformational movements at different temperatures. Our study provides an enhanced basis for future amide structural dynamics research.
KW - Amide bond
KW - Density functional theory
KW - Kinetic
KW - Nuclear magnetic resonance
KW - Rotational barrier energy
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UR - http://www.scopus.com/inward/citedby.url?scp=85053065867&partnerID=8YFLogxK
U2 - 10.3390/molecules23092294
DO - 10.3390/molecules23092294
M3 - Article
C2 - 30205542
AN - SCOPUS:85053065867
VL - 23
JO - Molecules
JF - Molecules
SN - 1420-3049
IS - 9
M1 - 2294
ER -