Synthesis and Chiral Recognition Properties of a Novel Colorimetric Chiral Sensor for Carboxylic Anions

2008 ◽  
Vol 61 (4) ◽  
pp. 310 ◽  
Author(s):  
Zhi-Hong Chen ◽  
Yong-Bing He ◽  
Chen-Guang Hu ◽  
Xiao-Huan Huang ◽  
Ling Hu
Keyword(s):  
Mass Spectrometry ◽  
1H Nmr ◽  
1H Nmr Spectroscopy ◽  
Chiral Recognition ◽  
Colour Change ◽  
Colorimetric Sensor ◽  
Naked Eye ◽  
Vis Spectroscopy ◽  
Carboxylic Anions ◽  
Stoichiometric Complex

Chiral colorimetric sensor 4 has been synthesized, and the structure characterized by IR and 1H NMR spectroscopy, mass spectrometry, and elemental analysis. The chiral recognition of the receptor was studied by 1H NMR and UV-vis spectroscopy. The results of non-linear curve fitting indicate that the receptor 4 and l- or d-mandelate and alanine anions form a 1:1 stoichiometric complex. The obvious colour change of receptor 4 can be observed by the naked eye when the enantiomers of mandelate and alanine anions are added, which demonstrates that receptor 4 may be used as the colorimetric sensor for the two carboxylic anions.

Discrimination of Enantiomers of Amides with Two Stereogenic Centers Enabled by Chiral Bisthiourea Derivatives Using 1H NMR Spectroscopy

2021 ◽  
Author(s):  
Hanchang Zhang ◽  
Hongmei Zhao ◽  
Jie Wen ◽  
Zhanbin Zhang ◽  
Pericles Stavropoulos ◽  
...  
Keyword(s):  
Amino Acids ◽  
Nmr Spectroscopy ◽  
1H Nmr ◽  
1H Nmr Spectroscopy ◽  
Chiral Recognition ◽  
Stereogenic Centers

Enantiomers of a few new amides containing two stereogenic centers have been derived from D- and L-α-amino acids as guests for chiral recognition by 1H NMR spectroscopy. A variety of...

scholarly journals CRYSTAL STRUCTURE AND TAUTOMERISM OF ALKYLAMINO-β-KETOENOLS IN SOLUTIONS

2019 ◽  
Vol 85 (8) ◽  
pp. 73-82
Author(s):  
VIKTOR CHERNII
Keyword(s):  
Mass Spectrometry ◽  
Nmr Spectroscopy ◽  
1H Nmr ◽  
Trifluoroacetic Acid ◽  
1H Nmr Spectroscopy ◽  
Keto Group ◽  
Polymethine Chain ◽  
X Ray Diffraction ◽  
The Stability ◽  
Crystalline System

The structure of alkylamino-β-ketoenols obtained by opening of the pyran cycle of chalcones based on dehydracetic acid was studied by X-ray diffraction, IR, 1H NMR spectroscopy and chromatography-mass spectrometry. The infrared spectra of the compounds appear to be typical of β-ketoenols. The crystalline structure (2Z,5Z,7E,9E)-6-hydroxy-2-(methylami-no)-10-phenylethoxy-2,5,7,9-tetraene-4-one was first determined. A comparative analysis of it with 2 pre-viously published structures has been carried out. All of these compounds are crystallized in the form of yellow plates in the monoclinic crystalline system (spatial group P21/n), they have a planar arrangement of the polyene chain and β-ketoenol fragment con-jugated to the aromatic ring. It has been established that the planar configuration of the β-ketoenol fragment is stabilized by hydrogen bonds between the hydroxy and keto group and the amino and keto group in the crystalline state. The length of the polymethine chain, the nature of the substituents in the aromatic and aliphatic part of the molecule do not significantly affect the size and geometry of the alkylamino-β-ketoenolate fragment. Approximately the same lengths of bonds, the distance between atoms and the corners indicate that all these com-pounds may have similar chelating properties. Ac-cording to 1H NMR spectroscopy in various deu-terated solvents (benzene, DMSO, chloroform, ace-tone, methanol and trifluoroacetic acid), most of the main signals of the obtained compounds have sa-tellites, which indicates the existence of several isomeric forms in solutions. The analysis of integral intensities of labile protons in 1H NMR spectra does not allow to obtain accurate results regarding the ratio of tautomers in a solution, but for a series of compounds their approximate ratio in chloroform, DMSO and trifluoroacetic acid have been established (from 70:30 in CDCl3 to 90:10 in DMSO and CF3CO2D). The stability of the tautomers in the solutions is confirmed by the data of chromatogra-phy-mass spectrometry.

Synthesis and properties of new N,N′-phenyltetrazole podand

2016 ◽  
Vol 70 (3) ◽  
Author(s):  
Agnieszka Pazik ◽  
Beata Kamińska ◽  
Anna Skwierawska ◽  
Sandra Nakonieczna ◽  
Tadeusz Ossowski
Keyword(s):  
Colour Change ◽  
Electrochemical Methods ◽  
Naked Eye ◽  
Vis Spectroscopy ◽  
Eye Colour

AbstractThe synthesis of a new chromogenic N,N′-phenyltetrazole receptor is reported here. The cationbinding properties of this receptor in solution were investigated by naked-eye colour change, electrochemical methods and UV-Vis spectroscopy in various solvents (CH

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