TY  - JOUR
AU  - Wang, Bao-Yu
AU  - Bao, Xiaoguang
AU  - Yan, Zhiqing
AU  - Maslak, Veselin
AU  - Hadad, Christopher M.
AU  - Bađić, Jovica D.
PY  - 2008
UR  - https://cherry.chem.bg.ac.rs/handle/123456789/981
AB  - Molecular basket 1, composed of a semirigid tris-norbornadiene framework and three revolving pyridine-based gates at the rim, has been built to "dynamically" enclose space and as such regulate molecular encapsulation. The gates were shown to fold via intramolecular hydrogen bonding and thereby form a G(3v) symmetrical receptor: the (1)H NMR resonance for the amide N-H protons of the pyridine gates appeared downfield (delta = 10.98 ppm), and the N-H vibrational stretch (IR) was observed at 3176 cm(-1). Accordingly, density functional theory (DFT, B3LYP) investigations revealed for the closed conformers of 1 to be energetically the most stable and dominant. The gearing of the pyridine "gates", about their axis, led to the interconversion of two dynamic enantiomers 1(A) and 1(B) comprising the clockwise and counterclockwise seam of intramolecular hydrogen bonds. Dynamic (1)H NMR spectroscopic measurements and line-shape simulations suggested that the energy barrier of 10.0 kcal/mol (Delta G(A/B)(double dagger), 298 K) is required for the 1(A/B) interconversion, when CCl(4) occupies the cavity of 1. Likewise, the activation free energy for CCl4 departing the basket was found to be 13.1 kcal/mol (Delta G(double dagger), 298 K), whereas the thermodynamic stability of 1:CCl(4) complex was -2.7 kcal/mol (Delta G degrees, 298 K). In view of that, CCI4 (but also (CH(3))(3)CBr) was proposed to escape from, and a molecule of solvent to enter, the basket when the gates rotate about their axis: the exit of CCl(4) requires the activation energy of 12.7 kcal/mol (Delta G(A/B)(double dagger) + Delta G degrees), similar to the experimentally found 13.1 kcal/mol (Delta G(double dagger)).
PB  - Amer Chemical Soc, Washington
T2  - Journal of the American Chemical Society
T1  - A 3-fold "Butterfly Valve" in Command of the Encapsulation's Kinetic Stability. Molecular Baskets at Work
VL  - 130
IS  - 45
SP  - 15127
EP  - 15133
DO  - 10.1021/ja8041977
ER  - 

@article{
author = "Wang, Bao-Yu and Bao, Xiaoguang and Yan, Zhiqing and Maslak, Veselin and Hadad, Christopher M. and Bađić, Jovica D.",
year = "2008",
abstract = "Molecular basket 1, composed of a semirigid tris-norbornadiene framework and three revolving pyridine-based gates at the rim, has been built to "dynamically" enclose space and as such regulate molecular encapsulation. The gates were shown to fold via intramolecular hydrogen bonding and thereby form a G(3v) symmetrical receptor: the (1)H NMR resonance for the amide N-H protons of the pyridine gates appeared downfield (delta = 10.98 ppm), and the N-H vibrational stretch (IR) was observed at 3176 cm(-1). Accordingly, density functional theory (DFT, B3LYP) investigations revealed for the closed conformers of 1 to be energetically the most stable and dominant. The gearing of the pyridine "gates", about their axis, led to the interconversion of two dynamic enantiomers 1(A) and 1(B) comprising the clockwise and counterclockwise seam of intramolecular hydrogen bonds. Dynamic (1)H NMR spectroscopic measurements and line-shape simulations suggested that the energy barrier of 10.0 kcal/mol (Delta G(A/B)(double dagger), 298 K) is required for the 1(A/B) interconversion, when CCl(4) occupies the cavity of 1. Likewise, the activation free energy for CCl4 departing the basket was found to be 13.1 kcal/mol (Delta G(double dagger), 298 K), whereas the thermodynamic stability of 1:CCl(4) complex was -2.7 kcal/mol (Delta G degrees, 298 K). In view of that, CCI4 (but also (CH(3))(3)CBr) was proposed to escape from, and a molecule of solvent to enter, the basket when the gates rotate about their axis: the exit of CCl(4) requires the activation energy of 12.7 kcal/mol (Delta G(A/B)(double dagger) + Delta G degrees), similar to the experimentally found 13.1 kcal/mol (Delta G(double dagger)).",
publisher = "Amer Chemical Soc, Washington",
journal = "Journal of the American Chemical Society",
title = "A 3-fold "Butterfly Valve" in Command of the Encapsulation's Kinetic Stability. Molecular Baskets at Work",
volume = "130",
number = "45",
pages = "15127-15133",
doi = "10.1021/ja8041977"
}

Wang, B., Bao, X., Yan, Z., Maslak, V., Hadad, C. M.,& Bađić, J. D.. (2008). A 3-fold "Butterfly Valve" in Command of the Encapsulation's Kinetic Stability. Molecular Baskets at Work. in Journal of the American Chemical Society
Amer Chemical Soc, Washington., 130(45), 15127-15133.
https://doi.org/10.1021/ja8041977

Wang B, Bao X, Yan Z, Maslak V, Hadad CM, Bađić JD. A 3-fold "Butterfly Valve" in Command of the Encapsulation's Kinetic Stability. Molecular Baskets at Work. in Journal of the American Chemical Society. 2008;130(45):15127-15133.
doi:10.1021/ja8041977 .

Wang, Bao-Yu, Bao, Xiaoguang, Yan, Zhiqing, Maslak, Veselin, Hadad, Christopher M., Bađić, Jovica D., "A 3-fold "Butterfly Valve" in Command of the Encapsulation's Kinetic Stability. Molecular Baskets at Work" in Journal of the American Chemical Society, 130, no. 45 (2008):15127-15133,
https://doi.org/10.1021/ja8041977 . .