SCF CI calculation of the electronic spectra of cis and trans isomers of stilbene and azo-benzene

1964 ◽  
Vol 2 (3) ◽  
pp. 215-218 ◽  
Author(s):  
Rama Basu
1970 ◽  
Vol 48 (10) ◽  
pp. 1481-1491 ◽  
Author(s):  
E. J. Bounsall ◽  
S. R. Koprich

A series of complexes of the type Rh(cyclam)X2+ and Rh(cyclam)XYn+ have been prepared and characterized, where cyclam represents 1,4,8,11-tetraazacyclotetradecane and X and Y represent OH−, H2O, Cl−, Br−, I−, N3−, NCS−, and NO2−. The infrared and electronic spectra are discussed with respect to assignment of the cis and trans isomers, the linkage isomers, and the Rh–ligand stretching frequencies above 250 cm−1. The thermodynamic trans effect is related to shifts in the Rh–ligand stretching frequencies. The intensities of the d–d transitions are related to distortion of the octahedral field to support the cis and trans assignments, and compared to show the decrease in bond constraint for propylene linkages in place of ethylene. Steric constraint accounts for the single case of stereoisomerization by cis-Rh(cyclam)I2+.


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 ◽  
...  

1957 ◽  
Vol 35 (8) ◽  
pp. 757-760 ◽  
Author(s):  
K. K. Carroll

The malonic ester synthesis of nervonic acid (tetracos-15-enoic acid) has been modified so that the product consists of pure cis rather than a mixture of cis and trans isomers. The modified synthesis has been used for the preparation of C14-labelled erucic and nervonic acids.


2002 ◽  
Vol 67 (1) ◽  
pp. 47-54 ◽  
Author(s):  
Zenon Łotowski ◽  
Jacek W. Morzycki ◽  
Izabella S. Niewczas ◽  
Marta Zdanowicz

Treatment of 16α-bromo-17-oxosteroids 1 and 2 with gaseous ammonia and successive air-oxidation afforded the cis and trans isomers of D-linked bis-steroid pyrazines. Analogous reaction of 1α-bromo-4-nor-5α-cholestan-2-one (3) led to unexpected hydrolysis products.


1965 ◽  
Vol 7 (8) ◽  
pp. 1504-1509 ◽  
Author(s):  
R.S. Muromova ◽  
I.D. Pletneva ◽  
T.V. Demidova ◽  
I.V. Shkhiyants ◽  
G.A. Tokareva

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