TY - JOUR
T1 - An evidence for the chiral discrimination of naproxen enantiomers
T2 - A combined experimental and theoretical study
AU - Wei, Yanli
AU - Wang, Sufang
AU - Chao, Jianbin
AU - Wang, Songbai
AU - Dong, Chuan
AU - Shuang, Shaomin
AU - Paau, Man Chin
AU - Choi, Martin M.F.
N1 - Financial support from the National Natural Science Foundation of China (20875059), Natural Science Foundation of Shanxi Province (2010021010-2), and Research Project Supported by Shanxi Scholarship Council of China (200809) is gratefully acknowledged.
PY - 2011/3/17
Y1 - 2011/3/17
N2 - Naproxen enantiomers possess strong room temperature phosphorescence (RTP) in β-cyclodextrin (β-CD) system with a small amount of 1,2-dibromoethane (1,2-DBE) under ambient conditions. The effects of pH, concentration of β-CD, and 1,2-DBE on the RTP of naproxen enantiomers have been investigated in detail. Time-resolved RTP spectroscopy shows that both naproxen enantiomers exhibit biexponential decay pattern with lifetimes of τ1 = 4.79 ± 0.13 and τ2 = 1.51 ± 0.096 ms for R-naproxen and τ1 = 6.67 ± 0.15 and τ2 = 2.13 ± 0.061 ms for S-naproxen. The lifetime differences between these enantiomers are δτ1 = 1.88 and δτ2 = 0.62 ms, indicating that chiral discrimination of naproxen enantiomers can be achieved in β-CD/1,2-DBE system. Naproxen enantiomers can form stable complexes with β-CD and 1,2-DBE in stoichiometric ratios of 1:1:2 and 1:1:1 (naproxen:β-CD:1,2-DBE), and the association constants are 3.20 × 103 M-4 and 2.43 × 103 M-3 for the S- and R-enantiomers, respectively. The chiral discrimination of R-naproxen and S-naproxen is realized via their difference in interaction with the chiral cavity of β-CD due to their difference in stereochemical structure. Finally, molecular modeling is performed to determine the chiral recognition on a molecular level, and the results are in good agreement with the experimental data.
AB - Naproxen enantiomers possess strong room temperature phosphorescence (RTP) in β-cyclodextrin (β-CD) system with a small amount of 1,2-dibromoethane (1,2-DBE) under ambient conditions. The effects of pH, concentration of β-CD, and 1,2-DBE on the RTP of naproxen enantiomers have been investigated in detail. Time-resolved RTP spectroscopy shows that both naproxen enantiomers exhibit biexponential decay pattern with lifetimes of τ1 = 4.79 ± 0.13 and τ2 = 1.51 ± 0.096 ms for R-naproxen and τ1 = 6.67 ± 0.15 and τ2 = 2.13 ± 0.061 ms for S-naproxen. The lifetime differences between these enantiomers are δτ1 = 1.88 and δτ2 = 0.62 ms, indicating that chiral discrimination of naproxen enantiomers can be achieved in β-CD/1,2-DBE system. Naproxen enantiomers can form stable complexes with β-CD and 1,2-DBE in stoichiometric ratios of 1:1:2 and 1:1:1 (naproxen:β-CD:1,2-DBE), and the association constants are 3.20 × 103 M-4 and 2.43 × 103 M-3 for the S- and R-enantiomers, respectively. The chiral discrimination of R-naproxen and S-naproxen is realized via their difference in interaction with the chiral cavity of β-CD due to their difference in stereochemical structure. Finally, molecular modeling is performed to determine the chiral recognition on a molecular level, and the results are in good agreement with the experimental data.
UR - http://www.scopus.com/inward/record.url?scp=79953191150&partnerID=8YFLogxK
U2 - 10.1021/jp108464r
DO - 10.1021/jp108464r
M3 - Journal article
AN - SCOPUS:79953191150
SN - 1932-7447
VL - 115
SP - 4033
EP - 4040
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
IS - 10
ER -