Association between halothane and oxygenated solvents by 1H NMR spectroscopy

1995 ◽  
Vol 73 (9) ◽  
pp. 1406-1411 ◽  
Author(s):  
Marcela Tkadlecová ◽  
Jaroslav Havlíček ◽  
Vladimír Dohnal
Keyword(s):  
Nmr Spectroscopy ◽  
Complex Formation ◽  
Equilibrium Constants ◽  
Solution Model ◽  
Methyl Tert Butyl Ether ◽  
Ideal Solution ◽  
Butyl Ether ◽  
Complex Formation Equilibria ◽  
H Nmr ◽  
Halothane Concentration

Using 1H NMR spectroscopy the complex-formation equilibria between halothane (2-bromo-2-chloro-1,1,1-trifluoroethane) and methyl tert-butyl ether or tetrahydrofuran in various inert solvents (hexane, heptane, decane, cyclohexane) were measured as a function of temperature. For two different association models (ideal solution and athermal solution), assuming only the formation of a 1:1 H-bonded complex, the equilibrium constants and the standard enthalpies of the complex-formation reaction were calculated. The ideal solution model provides values of the equilibrium constant that differ for different inert solvents. The athermal solution model makes this false solvent effect much smaller. For the low halothane concentration used, its dimerization was neglected. This assumption was verified experimentally. Keywords: 1H NMR, association, complex formation, halothane.

Equilibrium Constants for Methyl tert-Butyl Ether and Ethyl tert-Butyl Ether Liquid-Phase Syntheses using C4 Olefinic Cut

1994 ◽  
Vol 33 (11) ◽  
pp. 2830-2835 ◽  
Author(s):  
Jose F. Izquierdo ◽  
Fidel Cunill ◽  
Meritxell Vila ◽  
Montserrat Iborra ◽  
Javier Tejero
Keyword(s):  
Liquid Phase ◽  
Equilibrium Constants ◽  
Methyl Tert Butyl Ether ◽  
Butyl Ether ◽  
Tert Butyl

scholarly journals NMR Study of the Complex Formation in Solution

2018 ◽  
Vol 1 (3) ◽  
pp. e00025
Author(s):  
V.O. Zavelsky ◽  
I.P. Kalashnikova ◽  
V.P. Kazachenko ◽  
V.E. Baulin ◽  
O.A. Raevsky
Keyword(s):  
Nmr Spectroscopy ◽  
Complex Formation ◽  
13C Nmr ◽  
Nmr Spectra ◽  
Equilibrium Constants ◽  
High Sensitivity ◽  
Organic Ligands ◽  
Nmr Method ◽  
Natural Concentration ◽  
Nmr Study

NMR spectroscopy has been used to study the complexation of organic ligands, that are of interest for biology and medicine, with ions of biologically significant metals (Li+, Na+, Ca2 +, Ga3+). The possibilities and advantages of NMR spectroscopy methods in the study of complex formation are shown. A high sensitivity of the NMR signal to the formation of a complex even with a very small natural concentration of the magnetic isotopes is detected. The formation of a complex with a low stability constanthas has been found by 43Ca NMR spectroscopy. The equilibrium constants of the complexes and the parameters of their NMR spectra are obtained. The possibility of using the 31P and 13C NMR method for initial testing of the complexation of cyclene derivatives with the cation Ga3+ in D2O is shown.

Die reversible Dimerisierung von o-Phenylendioxydimethylsilan als Modell für die Oligomerisierung ringgespannter Kieselsäureester / The Reversible Dimerisation of o-Phenylenedioxydimethylsilane – an Example for the Oligomerisation Reactions of Ring-strained Organosiliconates

1975 ◽  
Vol 30 (7-8) ◽  
pp. 488-490 ◽  
Author(s):  
Heinrich Meyer ◽  
Günter Nagorsen ◽  
Armin Weiss
Keyword(s):  
Nmr Spectroscopy ◽  
Equilibrium Constants ◽  
Kcal Mole ◽  
Ring Strain ◽  
H Nmr

The dimerisation equilibrium of o-phenylenedioxydimethylsilane (2,2-dimethyl-1,3,2-benzodioxasilole) has been established and studied by 1H NMR spectroscopy. Equilibrium constants between 36 and 130°C have been determined. The enthalpy of dimerisation (about 5 kcal/mole) was obtained from these data and was attributed mainly to ring strain in the five membered dioxasilole ring. A mechanism for the reaction has been proposed.

Equilibrium constants for methyl tert-butyl ether liquid-phase synthesis

1992 ◽  
Vol 37 (3) ◽  
pp. 339-343 ◽  
Author(s):  
Jose Felipe Izquierdo ◽  
Fidel Cunill ◽  
Meritxell Vila ◽  
Javier Tejero ◽  
Montserrat Iborra
Keyword(s):  
Liquid Phase ◽  
Equilibrium Constants ◽  
Methyl Tert Butyl Ether ◽  
Butyl Ether ◽  
Phase Synthesis ◽  
Tert Butyl

scholarly journals Lewis acid complexes of 1,2-diketones and their derivatives. The synthesis of seven-membered rings

1983 ◽  
Vol 61 (9) ◽  
pp. 1981-1986 ◽  
Author(s):  
Christopher Blackburn ◽  
Ronald F. Childs ◽  
Roger A. Kennedy
Keyword(s):  
Nmr Spectroscopy ◽  
Complex Formation ◽  
Lewis Acid ◽  
Proton Resonance ◽  
Vinyl Proton ◽  
Enol Ether ◽  
Charge Delocalization ◽  
Silyl Ethers ◽  
Downfield Shift ◽  
H Nmr

The structures and charge distributions of Lewis and complexes of butane-2,3-dione, 1, cyclohexane-1,2-dione, 2, and 2-methoxycyclohex-2-en-1-one, 5, have been investigated by 1H nmr spectroscopy. A 1:1 complex was formed between 1 and SnCl4 which appeared to have a bridged structure. In the case of 2 and 5 both oxygens were again involved in complex formation with TiCl4 or SnCl4. In each case the large downfield shift of the vinyl proton resonance, H3, indicated extensive charge delocalization within the complexes and that these systems can be regarded as complexed α,β-unsaturated enones. The reactions of Lewis acid complexes of 2, 5, and the silyl ethers 2-(trimethylsiloxy)cyclohex-2-en-1-one, and 3-(trimethylsiloxy)-but-3-en-2-one, 11, with butadiene have been investigated. The acyclic enol ether 11 reacted with butadiene in the presence of either TiCl4 or SnCl4 to give products corresponding to both 4C + 3C and 4C + 2C cycloaddition reactions; in all other cases 4C + 2C products only could be isolated.

Complex Formation of Carnosine with Purine Nucleotides in Aqueous Solution

1980 ◽  
Vol 35 (7-8) ◽  
pp. 557-561 ◽  
Author(s):  
Klaus J. Neurohr ◽  
Henry H. Mantsch
Keyword(s):  
Aqueous Solution ◽  
Complex Formation ◽  
Equilibrium Constants ◽  
Purine Nucleotide ◽  
Purine Nucleotides ◽  
Purine Base ◽  
H Nmr ◽  
Nmr Study ◽  
Stacking Pattern ◽  
Proton Resonances

This 1H-NMR study provides experimental evidence for an intermolecular interaction between the dipeptide camosine (β-alanyl-ʟ-histidine) and the purine nucleoside 5′-monophosphates 5′-AMP, 5′-IMP and 5′-GMP. From the observed upfield shifts of the purine nucleotide and imidazole proton resonances it is concluded that the interaction is of the stacking type and that it involves the purine base of the nucleotide and the histidine moiety of camosine. Apparent microscopic equilibrium constants and complex shifts are obtained with a microscopic model, which considers the formation of both 1:1 and 1:2 complexes. The stacking pattern for complex formation between the histidine moiety of camosine and the adenine moiety of 5′-AMP is constructed by Fitting the experimental 5′-AMP complex shifts to the calculated isoshielding contours for histidine.

Darstellung und Reaktionen der Oxovanadin(V)-tricarboxylate / Synthesis and Reactions of Oxovanadium(V) Tricarboxylates

1980 ◽  
Vol 35 (7) ◽  
pp. 817-823 ◽  
Author(s):  
Fritz Preuss ◽  
Willi Towae ◽  
Joachim Woitschach
Keyword(s):  
Nmr Spectroscopy ◽  
Carboxylic Acid ◽  
Complex Formation ◽  
Chemical Reactions ◽  
Acid Anhydride ◽  
Carboxylate Ligands ◽  
H Nmr ◽  
Silver Carboxylate ◽  
Carboxylic Acid Anhydride

Monomeric oxovanadium(V) tricarboxylates VO(RCOO)3 are prepared by reaction of VOCl3 with an excess of silver carboxylate in CH2Cl2 or by depolymerization of (VO2RCOO)n in carboxylic acid anhydride. Their properties are studied by IR and 1H NMR spectroscopy as well as by chemical reactions such as thermolysis, solvolysis, redistribution and complex formation. The structure of 2,2′-dipyridyl and 1,10-phenanthroline complexes [VO(RCOO)3 · B] (B = C10H8N2, C12H8N2) has been found to be octahedral with meridional arrangement of the carboxylate ligands. Syntheses of Na[VO(CH3COO)4] and Ba[VO2(CH3COO)3] · 2CH3COOH are described

Sign in / Sign up

Export Citation Format

Share Document