Encapsulation of sodium alkyl sulfates by the cyclotriveratrylene-based, [Pd6L8]12+ stella octangula cage

2014 ◽  
Vol 43 (15) ◽  
pp. 5657-5661 ◽  
Author(s):  
Nikki J. Cookson ◽  
James J. Henkelis ◽  
Richard J. Ansell ◽  
Colin W. G. Fishwick ◽  
Michaele J. Hardie ◽  
...  
Keyword(s):  
Alkyl Sulfate ◽  
Nmr Studies ◽  
H Nmr ◽  
Sodium Alkyl Sulfates ◽  
Alkyl Sulfates ◽  
Chain Lengths

1H NMR studies have revealed that a [Pd6L8]12+ stella octangula cage can act as host to two molecules of alkyl sulfate; with chain lengths of 8–14 carbons.

Bis-imidazolium salts with alkyl sulfates as counterions: synthesis and liquid crystalline properties

2017 ◽  
Vol 41 (19) ◽  
pp. 11113-11124 ◽  
Author(s):  
Theodora A. Ilincă ◽  
Iuliana Pasuk ◽  
Viorel Cîrcu
Keyword(s):  
Liquid Crystalline ◽  
Alkyl Sulfate ◽  
Imidazolium Salts ◽  
Alkyl Sulfates ◽  
Chain Lengths

A series of flexibly linked bis-imidazolium salts with alkyl sulfate anions having different chain lengths (10, 12, 14) was investigated for their thermotropic behavior.

1H NMR Conformational Studies in Water of Angiotensin II Analogues Modified at the N- and C-Termini: Interactions of the Aromatic Side Chains and Folding of the N-Terminal Domain

1994 ◽  
Vol 59 (11) ◽  
pp. 2523-2532 ◽  
Author(s):  
John Hondrelis ◽  
John Matsoukas ◽  
George Agelis ◽  
Paul Cordopatis ◽  
Ning Zhou ◽  
...  
Keyword(s):  
Shielding Effect ◽  
Resonance Spectroscopy ◽  
Nmr Studies ◽  
Previous Suggestion ◽  
Aminoisobutyric Acid ◽  
H Nmr ◽  
Neutral Ph ◽  
Angiotensin Ii Analogues ◽  
Proton Resonances ◽  
Cosy Nmr

The conformation of [Sar1]angiotensin II in water at neutral pH has been examined by proton magnetic resonance spectroscopy at 400 MHz and in particular by comparing its 1H NMR spectral data with those of analogues modified at positions 1,4 and 6, namely [Sar1,Cha8]ANGII, [Des Asp1,Cha8]ANGII, [Aib1,Tyr(Me)4]ANGII, [Aib1,Tyr(Me)4,Ile8]ANGII, [N-MeAib1,Tyr(Me)4]ANGII, [N-MeAib1,Tyr(Me)4,Ile8]ANGII, ANGIII and [Sar1,Ile8]ANGII. Assignment of all proton resonances in these analogues was made possible by 2D COSY NMR experiments. The H-2 and H-4 protons for the histidine ring in [Sar1]ANGII, ANGII and ANGIII were shielded compared with the same protons in [Sar1,Ile8]ANGII, [Sar1,Cha8]ANGII and [Des Asp1,Cha8]ANGII; this shielding effect was not disturbed upon methylation of the tyrosine hydroxyl and/or replacement of residue 1 (sarcosine or aspartic acid) with aminoisobutyric acid (Aib) or N-methyl aminoisobutyric acid (N-MeAib). These data are consistent with our previous suggestion based on NMR studies in neutral DMSO that a characteristic folded conformation for ANGII previously observed in non-polar solvents can also be detected in water at neutral pH, but to a lesser degree.

Rotationsbarriere der Endgruppen bei Poly- methinoxonolen verschiedener Kettenlänge / Rotation Barrier of the End Groups of Polymethine Oxonols with Different Chain Lengths

1976 ◽  
Vol 31 (8) ◽  
pp. 1017-1018 ◽  
Author(s):  
H. Oehling ◽  
F. Baer
Keyword(s):  
Nmr Spectra ◽  
Rotation Barrier ◽  
Free Enthalpy ◽  
Temperature Dependent ◽  
Restricted Rotation ◽  
H Nmr ◽  
Enthalpy Of Activation ◽  
End Groups ◽  
Electron Contribution ◽  
Chain Lengths

Abstract Polymethine oxonols show temperature dependent 1H-NMR-spectra because of restricted rotation of the end groups. The dependence of the value of the corresponding free enthalpy of activation AGt on the length of the poly-methine chain can be explained by the change of the π-electron contribution to ⊿G≠.

High field 1H NMR Studies of Sol-Gel Kinetics

1986 ◽  
Vol 73 ◽  
Author(s):  
Bruce D. Kay ◽  
Roger A. Assink
Keyword(s):  
Equilibrium Distribution ◽  
Sol Gel ◽  
Nmr Studies ◽  
H Nmr ◽  
Rate Limiting Step ◽  
Rate Of Hydrolysis ◽  
Acid Catalyzed ◽  
Product Species ◽  
Rate Limiting ◽  
Kinetics Of

ABSTRACTHigh resolution 1H NMR spectroscopy at high magnetic fields is employed to study the reaction kinetics of the Si(OCH3)4:CH3OH:H2O sol-gel system. Both the overall extent of reaction as a function of time and the equilibrium distribution of species are measured. In acid catalyzed solution, condensation is the rate limiting step while in base catalyzed solution, hydrolysis becomes rate limiting. A kinetic model in which the rate of hydrolysis is assumed to be independent of the adjacent functional groups is presented. This model correctly predicts the distribution of product species during the initial stages of the sol-gel reaction.

Equilibrium thermodynamic studies for the formation of 1:1 complexes of CO and ethene with a rhodium(II) porphyrin metallo-radical

2001 ◽  
Vol 79 (5-6) ◽  
pp. 854-856 ◽  
Author(s):  
Leah Basickes ◽  
Andrew G Bunn ◽  
Bradford B Wayland
Keyword(s):  
Carbon Monoxide ◽  
Complex Formation ◽  
Equilibrium Thermodynamic ◽  
Nmr Studies ◽  
Thermodynamic Studies ◽  
H Nmr ◽  
Porphyrin Ligand ◽  
The One ◽  
Paramagnetic Shifts

Tetra(2,4,6 triisopropropyl phenyl)porphyrinatorhodium(II) ((TTiPP)RhII·1) is a persistent metal-centered radical with the odd electron in the rhodium(II) dz2 orbital. (TTiPP)RhII· forms 1:1 complexes with CO and CH2CH2 where the porphyrin ligand steric properties inhibit further reactions of the one-electron activated substrates. 1H NMR paramagnetic shifts at a series of temperatures are used in evaluating the thermodynamics for CO complex formation with 1 to form [(TTiPP)RhII(CO)]·2 (ΔH° = -5.5 ± 0.5 kcal mol-1; ΔS° = -9 ± 1 cal K-1 mol-1). Related 1H NMR studies show that the bonding of 1 with ethene is less favorable than CO.Key words: rhodium porphyrin, carbon monoxide, ethene, thermodynamics, complex formation, metal-centered radical.

Sodium alkyl sulfates as maximum suppressors

1972 ◽  
Vol 40 (2) ◽  
pp. 419-429 ◽  
Author(s):  
Vinay Kumar ◽  
T.W. Gilbert
Keyword(s):  
Sodium Alkyl Sulfates ◽  
Alkyl Sulfates

The synthesis of 11R- and 11S-HETE and of 11-R,S-HPETE methyl esters

1983 ◽  
Vol 61 (4) ◽  
pp. 712-717 ◽  
Author(s):  
George Just ◽  
Corinne Luthe ◽  
Minh Tan Phan Viet
Keyword(s):  
Methyl Esters ◽  
Nmr Studies ◽  
H Nmr ◽  
Conformational Properties

Methyl 11R- and 11S-hydroxyeicosa-5Z,8Z,12E,14Z-tetraenoate (17R, 17S) (11-HETE) and the corresponding 11-hydroperoxide 19 (11-HPETE) have been prepared from readily available starting materials. The yields were approximately 25% for 11R,S-HETE, and 5% each for 11R- and 11S-HETE.Extensive 400 MHz 1H nmr studies of 17 (nOe difference, 2D J-resolved) were undertaken to confirm the structure. Some conformational properties are discussed.

scholarly journals 1H NMR Studies of Surfactants in Aqueous Solutions

2003 ◽  
Vol 19 (07) ◽  
pp. 675-680 ◽  
Author(s):  
Mao Shi-Zhen ◽  
◽  
Du You-Ru
Keyword(s):  
Aqueous Solutions ◽  
Nmr Studies ◽  
H Nmr
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