65283-60-5Relevant articles and documents
A coumarin-based chiral fluorescence sensor for the highly enantioselective recognition of phenylalaninol
Jiao, Jiemin,Liu, Xunhua,Mao, Xuerong,Li, Junfeng,Cheng, Yixiang,Zhu, Chengjian
, p. 317 - 322 (2013)
A chiral host L1 incorporating (S)-BINOL and substituted coumarin moieties was synthesized via a nucleophilic addition-elimination reaction, and ligand L2 could be obtained by the reduction reaction of the imine-based L1 with NaBH 4. The fluorescence responses of chiral compounds L1 and L2 on (l)-/(d)-phenylalaninol were investigated by fluorescence spectra. The fluorescence intensity of L1 in cooperation with (l)-/(d)-phenylalaninol shows a gradual enhancement upon addition of (l)-/(d)-phenylalaninol and keeps a nearly linear correlation with the concentration molar ratios from 1:10 to 1:180. Stoichiometries and association constants of L1 with (l)-/(d)-phenylalaninol were calculated. The results indicate that chiral sensor L1 can exhibit a remarkable "turn-on" fluorescence enhancement response and excellent enantioselective behaviour for (l)-phenylalaninol by direct visual observation at low concentration, and the value of the enantiomeric fluorescence difference ratio (ef) is 3.07. On the contrary, no obvious fluorescence response and enantioselective recognition effect can be detected for L2 towards either (l)-/(d)-phenylalaninol.
A fluorescence sensor based on chiral polymer for highly enantioselective recognition of phenylalaninol
Meng, Jie,Wei, Guo,Huang, Xiaobo,Dong, Yu,Cheng, Yixiang,Zhu, Chengjian
, p. 363 - 367 (2011)
The chiral polymer P-1 incorporating (S)-2,2′-binaphthol (BINOL) and (S)-2,2′-binaphthyldiamine (BINAM) moieties in the main chain of the polymer backbone was synthesized by the polymerization of (S)-6,6′- dibutyl-3,3′-diformyl-2,2′-binaphthol (S-M-1) with (S)-2,2′-binaphthyldiamine (S-M-2) via nucleophilic addition-elimination reaction, and the chiral polymer P-2 could be obtained by the reduction reaction of P-1 with NaBH4. The fluorescence intensity of the chiral polymer P-1 exhibits gradual enhancement upon addition of (d)- or (l)-phenylalaninol and keeps nearly a linear correlation with the concentration molar ratios of (d)- or (l)-phenylalaninol. The value of enantiomeric fluorescence difference ratio (ef) is 6.85 for the chiral polymer on (d)-phenylalaninol. On the contrary, the chiral polymer P-2 shows no obvious fluorescence response toward either (d)- or (l)-phenylalaninol.
Synthesis and fluorescent properties of a chiral conjugated polymer based on (S)-2,2′-binaphtho-20-crown-6
Huang, Hui,Miao, Qian,Kang, Yixiong,Huang, Xiaobo,Xu, Jinqian,Cheng, Yixiang
, p. 1116 - 1124 (2008)
Linear conjugated polymer was obtained by the polymerization of 2,3-dibutoxy-1,4-diethynylnaphthalene (M-l) and (S)-5,5′-dibromo-6, 6′-dibutyl-2,2′-binaphtho-20-crown-6 (S-M-2) via Pd-catalyzed Sonogashira reaction. The conjugated polymer shows strong green-blue fluorescence due to the extended Π-electronic structure between the chiral repeating unit (S)-6,6′-dibutyl-2,2′-binaphtho-20-crown-6 and the conjugated linker 2,3-dibutoxynaphthyl group via acetylene bridge. The responsive properties of the chiral polymer on K+, Pb2+, Hg2+, and AsIII were investigated by fluorescent spectra. The results show that Hg2+ and AsIII can cause effective fluorescent quenching of the polymer, whereas, K+ and Pb2+ do not produce obvious changes in the polymer fluorescence. The obvious fluorescent influence shows that the 2,2′-binaphtho-20-crown-6 moiety plays an important role in fluorescent recognition for Hg2+ and AsIII due to the effective photoinduced electron transfer (PET) and charge transfer (PCT) between the conjugated polymer backbone and receptor species.
Relationships between main-chain chirality and photophysical properties in chiral conjugated polymers
Zheng, Chao,An, Zhongfu,Nakai, Yosuke,Tsuboi, Taiju,Wang, Yang,Shi, Huifang,Chen, Runfeng,Li, Huanhuan,Ji, Yimu,Li, Junfeng,Huang, Wei
, p. 7336 - 7347 (2014)
A series of R- and S-binaphthyl-containing polyfluorenes, bearing different contents and types of axial chirality in the main chain, have been synthesized through Suzuki polycondensation to investigate the influence of the covalently incorporated chirality on the photophysical properties of chiral conjugated polymers. The experimental measurements obtained by UV-Vis and photoluminescence (PL) spectroscopy, cyclic voltammetry, and circular dichroism spectroscopy reveal that the chiral copolymers possess high thermostability, high luminescence efficiency, reversible electrochemical properties, and intrachain transferred dichroism. Surprisingly, the R-chiral polymers exhibit better spectral thermostability, stronger suppressing ability upon the β-phase formation of the main-chain, and higher PL quantum efficiency than S-chiral polymers in solid films. The theoretical insights obtained by either ab initio density functional theory (DFT) calculations or molecular dynamics (MD) simulations suggest that these differences probably resulted from the more planar chain conformation of S-chiral polymers, which leads to stronger interchain interaction and an increased tendency to form inefficient and unstable excimers or quenchers. The different effects of enantiomers on the photophysical properties of chiral conjugated polymers may provide an import update in the understanding of chiro-optics. This journal is the Partner Organisations 2014.
Irradiation-Wavelength Directing Circularly Polarized Luminescence in Self-Organized Helical Superstructures Enabled by Hydrogen-Bonded Chiral Fluorescent Molecular Switches
He, Yanrong,Zhang, Shu,Bisoyi, Hari Krishna,Qiao, Jinghui,Chen, Hong,Gao, JingJing,Guo, Jinbao,Li, Quan
supporting information, p. 27158 - 27163 (2021/10/25)
Two light-driven chiral fluorescent molecular switches, (R,S,R)-switch 1 and (R,S,R)-switch 2, are prepared by means of hydrogen-bonded (H-bonded) assembly of a photoresponsive (S) chiral fluorescent molecule, respectively with a cyano substitution at different positions as an H-bond acceptor and an opposite (R) chiral molecule as an H-bond donor. The resulting two switches exhibit tunable and reversible Z/E photoisomerization irradiated with 450 nm blue and 365 nm UV light. When doped into an achiral liquid crystal, both switches are found to be able to form a CPL tunable luminescent helical superstructure. In contrast to the tunable CPL characteristics of the system incorporating switch 2, exposure of the system incorporating switch 1 to 365 nm and 450 nm radiation can lead to controllable different photostationary CPL behavior, including switching-off and polarization inversion. In addition, optical information coding is demonstrated using the system containing switch 1.
Resolution of Vaulted Biaryl Ligands via Borate Esters of Quinine and Quinidine
Cagnon, Brian R.,Mohammadlou, Aliakbar,Wulff, William D.,Yin, Xiaopeng,Zheng, Li
, p. 10432 - 10450 (2020/09/23)
Given the sudden and unexplained rise in the cost of (+)- A nd (-)-sparteine, an alternative method for the resolution of vaulted biaryls has been developed. This method involves the reaction of a racemic vaulted biaryl ligand with one equivalent of BH3·SMe2 and one equivalent of either quinine or quinidine. A precipitate then forms from the resulting mixture of diastereomeric borates as a result of differential solubilities. Hydrolysis of the precipitate then liberates the (S)-ligand in the case of quinine and the (R)-ligand in the case of quinidine, both with >99% ee. This method has been applied to 16 different vaulted biaryl ligands, including 10 whose preparation is described here for the first time. In addition, proof of principle has been demonstrated for the dynamic thermodynamic resolution of the vaulted biaryl ligands with this method in combination with a nonchiral copper(II) complex that can racemize the ligand.
