Relative stability of the cis and trans isomers of octahedral cobalt(iii) complexes of the type [Co(N2O2)X2] with tetradentate salen type Schiff bases: a combined theoretical and experimental study

CrystEngComm ◽  
2019 ◽  
Vol 21 (40) ◽  
pp. 6026-6037
Author(s):  
Kousik Ghosh ◽  
Snehasis Banerjee ◽  
Shouvik Chattopadhyay
Keyword(s):  
Experimental Study ◽  
Dft Calculations ◽  
Schiff Bases ◽  
Relative Stability ◽  
Trans Isomers ◽  
Cis And Trans Isomers ◽  
Cis And Trans

Energies of cis and trans isomers of a series of octahedral cobalt(iii) complexes with salen type Schiff bases have been estimated by DFT calculations.

A Computational and Experimental Study on the Relative Stabilities of Cis and Trans Isomers ofN-Alkylamides in Gas Phase and in Solution

2002 ◽  
Vol 106 (19) ◽  
pp. 4942-4950 ◽  
Author(s):  
Antonio García Martínez ◽  
Enrique Teso Vilar ◽  
Amelia García Fraile ◽  
Paloma Martínez-Ruiz
Keyword(s):  
Experimental Study ◽  
Gas Phase ◽  
Trans Isomers ◽  
Relative Stabilities ◽  
Cis And Trans Isomers ◽  
Cis And Trans

scholarly journals Nucleophilic Substitution at Tetracoordinate Phosphorus.Stereochemical Course and Mechanisms of Nucleophilic Displacement Reactions at Phosphorus in Diastereomeric cis- and trans-2-Halogeno-4-methyl-1,3,2-dioxaphosphorinan-2-thiones: Experimental and DFT Studies

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3655
Author(s):  
Marian Mikołajczyk ◽  
Barbara Ziemnicka ◽  
Jan Krzywański ◽  
Marek Cypryk ◽  
Bartłomiej Gostyński
Keyword(s):  
Dft Calculations ◽  
Alkaline Hydrolysis ◽  
Density Functional ◽  
Phosphorus Pentachloride ◽  
Major Product ◽  
Trans Isomers ◽  
Cis And Trans Isomers ◽  
Displacement Reactions ◽  
Single Transition ◽  
Cis And Trans

Geometrical cis- and trans- isomers of 2-chloro-, 2-bromo- and 2-fluoro-4-methyl-1,3,2-dioxaphosphorinan-2-thiones were obtained in a diastereoselective way by (a) sulfurization of corresponding cyclic PIII-halogenides, (b) reaction of cyclic phosphorothioic acids with phosphorus pentachloride and (c) halogen–halogen exchange at PIV-halogenide. Their conformation and configuration at the C4-ring carbon and phosphorus stereocentres were studied by NMR (1H, 31P) methods, X-ray analysis and density functional (DFT) calculations. The stereochemistry of displacement reactions (alkaline hydrolysis, methanolysis, aminolysis) at phosphorus and its mechanism were shown to depend on the nature of halogen. Cyclic cis- and trans-isomers of chlorides and bromides react with nucleophiles (HO−, CH3O−, Me2NH) with inversion of configuration at phosphorus. DFT calculations provided evidence that alkaline hydrolysis of cyclic thiophosphoryl chlorides proceeds according to the SN2-P mechanism with a single transition state according to the potential energy surface (PES) observed. The alkaline hydrolysis reaction of cis- and trans-fluorides afforded the same mixture of the corresponding cyclic thiophosphoric acids with the thermodynamically more stable major product. Similar DFT calculations revealed that substitution at phosphorus in fluorides proceeds stepwise according to the A–E mechanism with formation of a pentacoordinate intermediate since a PES with two transition states was observed.

The relative stability of cis and trans isomers

1995 ◽  
Vol 341 (1-3) ◽  
pp. 141-147 ◽  
Author(s):  
L.L. Boyle ◽  
R.F. Hudson ◽  
J.D. Wallis
Keyword(s):  
Relative Stability ◽  
Trans Isomers ◽  
Cis And Trans Isomers ◽  
Cis And Trans

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
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