THE EFFECT OF SOLVENT AND TEMPERATURE ON THE CIS–TRANS ISOMERISM OF ORTHO-tert-ALKYL PHENOLS

1961 ◽  
Vol 39 (3) ◽  
pp. 481-487 ◽  
Author(s):  
K. U. Ingold ◽  
D. R. Taylor
Keyword(s):  
Trans Isomers ◽  
Infrared Band ◽  
Effect Of Solvent ◽  
Cis And Trans Isomers ◽  
Stretching Vibration ◽  
Alkyl Phenols ◽  
Enthalpy And Entropy ◽  
Cis And Trans

The effects of different solvents and of a change of temperature on the infrared band due to the fundamental hydroxyl stretching vibration in several 2,6-di-t-alkyl phenols and in the corresponding ortho-t-alkyl phenols have been examined. The conclusion that the two bands observed in ortho-t-alkyl phenols represent cis and trans isomers has been confirmed. The differences in enthalpy and entropy between the two isomers have been measured for six different phenols.

THE INFRARED FREQUENCIES AND INTENSITIES OF THE HYDROXYL BAND OF ORTHO-ALKYL PHENOLS IN THE VAPOR PHASE

1962 ◽  
Vol 40 (1) ◽  
pp. 111-121 ◽  
Author(s):  
K. U. Ingold
Keyword(s):  
Vapor Phase ◽  
Hydroxyl Group ◽  
Trans Isomers ◽  
Polar Solvents ◽  
Cis And Trans Isomers ◽  
Stretching Vibration ◽  
Alkyl Phenols ◽  
Infrared Frequencies ◽  
Cis And Trans ◽  
Hydroxyl Band

The infrared frequencies and intensities of the fundamental stretching vibration of the hydroxyl group have been measured for a number of ortho-alkyl phenols in the vapor phase over a range of temperatures. Both quantities have been shown to depend on internal steric and environmental factors. The differences in enthalpy between the cis and trans isomers of several 2-tert-alkyl phenols have been measured, and it is concluded that the latter are not significantly stabilized relative to the former by solvation in non-polar solvents.

THE INFRARED FREQUENCIES AND INTENSITIES OF THE HYDROXYL BAND IN ORTHO-SUBSTITUTED PHENOLS

1961 ◽  
Vol 39 (3) ◽  
pp. 471-480 ◽  
Author(s):  
K. U. Ingold ◽  
D. R. Taylor
Keyword(s):  
Alkyl Substituent ◽  
Hydroxyl Group ◽  
Cis And Trans Isomers ◽  
Stretching Vibration ◽  
Alkyl Phenols ◽  
The Difference ◽  
Ortho Cresol ◽  
Infrared Frequencies ◽  
Cis And Trans ◽  
Hydroxyl Band

The infrared frequencies, intensities, and half-band widths of the fundamental stretching vibration of the hydroxyl group have been measured for a large number of ortho-alkyl phenols. It has been found that phenols containing a single ortho-alkyl substituent exist as cis and trans isomers in unequal amounts, the trans isomer being the more abundant. The difference in free energy between the two isomers in dilute solution in carbon tetrachloride at 24 °C has been measured for ortho-cresol, 2,3-dimethyl phenol, and several ortho-tert-alkyl phenols.

scholarly journals Identification of Anthocyanin Compounds in Butterfly Pea Flowers (Clitoria ternatea L.) by Ultra Performance Liquid Chromatography/Ultraviolet Coupled to Mass Spectrometry

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4539
Author(s):  
Nguyen Minh Thuy ◽  
Vo Minh ◽  
Tran Ben ◽  
My Tuyen Thi Nguyen ◽  
Ho Ha ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Ultra Performance Liquid Chromatography ◽  
Negative Ion ◽  
Trans Isomers ◽  
Clitoria Ternatea ◽  
Flower Extract ◽  
Cis And Trans Isomers ◽  
Butterfly Pea ◽  
Cis And Trans

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.

Unveiling the coexistence of cis- and trans-isomers in the hydrolysis of ZrO2: A coupled DFT and high-resolution photoelectron spectroscopy study

2020 ◽  
Vol 153 (24) ◽  
pp. 244308
Author(s):  
Ali Abou Taka ◽  
Mark C. Babin ◽  
Xianghai Sheng ◽  
Jessalyn A. DeVine ◽  
Daniel M. Neumark ◽  
...  
Keyword(s):  
High Resolution ◽  
Photoelectron Spectroscopy ◽  
Spectroscopy Study ◽  
Trans Isomers ◽  
Cis And Trans Isomers ◽  
Cis And Trans ◽  
Hydrolysis Of

PREPARATION OF ERUCIC AND NERVONIC ACIDS LABELLED WITH CARBON-14

1957 ◽  
Vol 35 (8) ◽  
pp. 757-760 ◽  
Author(s):  
K. K. Carroll
Keyword(s):  
Enoic Acid ◽  
Nervonic Acid ◽  
Malonic Ester ◽  
Ester Synthesis ◽  
Trans Isomers ◽  
Carbon 14 ◽  
Cis And Trans Isomers ◽  
Cis And Trans

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.

Synthesis of cis and trans Isomers of D-Ring Linked Bis-Steroid Pyrazines from 16α-Bromo-17-oxosteroids

2002 ◽  
Vol 67 (1) ◽  
pp. 47-54 ◽  
Author(s):  
Zenon Łotowski ◽  
Jacek W. Morzycki ◽  
Izabella S. Niewczas ◽  
Marta Zdanowicz
Keyword(s):  
Gaseous Ammonia ◽  
Analogous Reaction ◽  
Air Oxidation ◽  
Trans Isomers ◽  
Hydrolysis Products ◽  
Cis And Trans Isomers ◽  
Cis And Trans

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.

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