ChemInform Abstract: CIS- AND TRANS-ISOMERS OF (RH(EN)2X2)(+) WHERE X=CL AND BR, POSSIBLE USE OF (13)C NMR SPECTROSCOPY IN THEIR IDENTIFICATION

1975 ◽  
Vol 6 (40) ◽  
Author(s):  
C. BURGESS ◽  
F. R. HARTLEY
1985 ◽  
Vol 40 (4) ◽  
pp. 470-476 ◽  
Author(s):  
J. K. Das ◽  
K. C. Dash

A number of mixed-ligand complexes of cobalt(III) containing coordinated azide ion, acetyl- acetonatc anion and the neutral base imidazole and, having the general formula [Co(acac)2(N3)(Im)] (Im = imidazole or its derivatives) have been synthesised by the reaction of K[trans-Co(acac)2(N3)2] with the biologically active ligand imidazole or its derivatives. IR and electronic spectra alongwith 1H and 13C NMR spectra have been employed to characterise the complexes and determine their geometry. In contrast to the stable trans-[Co(acac)2(NO2)(Im)] complexes, these azido complexes arc shown to undergo facile trans ⇋ cis interconversion in CHCl3 solution. The NMR spectra (1H and 13C) can be interpreted by assuming the presence of an equilibrium mixture of the cis- and trans-isomers in solution.


1981 ◽  
Vol 59 (24) ◽  
pp. 3313-3318 ◽  
Author(s):  
J. Cadet ◽  
R. Nardin ◽  
L. Voituriez ◽  
M. Remin ◽  
F. E. Hruska

N-(2′-Deoxy-β-D-erythropentofuranosyl) formamide is an ionizing radiation-induced degradation product of 2′-deoxythymidine. This work describes a facile chemical synthesis of this molecule, and discusses the results of an 1H and 13C nmr study. The rotational barrier to cis–trans isomerization about the amide linkage is calculated, and details of the molecular conformation of the cis and trans isomers in aqueous solution are presented.


Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4539
Author(s):  
Nguyen Minh Thuy ◽  
Vo Minh ◽  
Tran Ben ◽  
My Tuyen Thi Nguyen ◽  
Ho Ha ◽  
...  

Butterfly pea flower have great sensory attraction, but they have not yet been used widely in Vietnam. Extracts of butterfly pea flowers can be used conveniently as a natural blue colorant for food products. In this study, the identification of anthocyanin compounds in butterfly pea flowers was performed by UPLC coupled with a UV and Mass spectrometer instrument. Positive and negative ion electrospray MS/MS chromatograms and spectra of the anthocyanin compounds were determined. By analyzing the chromatograms and spectra for each ion, five anthocyanins were identified in the butterfly pea flower extract; these were delphinidin-3-(6”‐p-coumaroyl)-rutinoside, cyanidin 3-(6”-p-coumaroyl)-rutinoside, delphinidin-3-(p-coumaroyl) glucose in both cis- and trans- isomers, cyanidin-3-(p-coumaroyl-glucoside) and delphinidin-3-pyranoside. Additionally, based on their intensity, it was determined that cyanidin-3-(p-coumaroyl-glucoside) was the most abundant anthocyanin, followed by cyanidin 3-(6”-p-coumaroyl)-rutinoside, delphinidin-3-(p-coumaroyl-glucoside), delphinidin-3-(6”-p-coumaroyl)-rutinoside and delphinidin-3-pyranoside. In this study, cyanidin derivatives were discovered in butterfly pea flower extract, where these compounds had not been detected in previous studies.


2020 ◽  
Vol 153 (24) ◽  
pp. 244308
Author(s):  
Ali Abou Taka ◽  
Mark C. Babin ◽  
Xianghai Sheng ◽  
Jessalyn A. DeVine ◽  
Daniel M. Neumark ◽  
...  

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