scholarly journals Protons in Ambient Temperature Chloroaluminate Molten Salts: Electrochemical and NMR Studies of their Interaction with Dimethylaniline

1990 ◽  
Vol 1990-17 (1) ◽  
pp. 290-305
Author(s):  
Soo-Gil Park
Keyword(s):  
Ambient Temperature ◽  
Molten Salts ◽  
Nmr Studies

Lithium-7 NMR studies of macrobicyclic complexes in ambient temperature molten salts

Polyhedron ◽  
1988 ◽  
Vol 7 (15) ◽  
pp. 1341-1347 ◽  
Author(s):  
Rick R. Rhinebarger ◽  
Alexander I. Popov
Keyword(s):  
Ambient Temperature ◽  
Molten Salts ◽  
Nmr Studies

Friedel-Crafts reactions in ambient-temperature molten salts

1986 ◽  
Vol 51 (4) ◽  
pp. 480-483 ◽  
Author(s):  
Jeffrey A. Boon ◽  
Joseph A. Levisky ◽  
J. Lloyd Pflug ◽  
John S. Wilkes
Keyword(s):  
Ambient Temperature ◽  
Molten Salts

scholarly journals Dynamic aspect of bacteriorhodopsin as viewed from13C NMR: Conformational elucidation, surface dynamics and information transfer from the surface to inner residues

2002 ◽  
Vol 16 (3-4) ◽  
pp. 107-120 ◽  
Author(s):  
H. Saitô ◽  
R. Kawaminami ◽  
M. Tanio ◽  
T. Arakawa ◽  
S. Yamaguchi ◽  
...  
Keyword(s):  
Ambient Temperature ◽  
Information Transfer ◽  
Side Chain ◽  
Amino Acid Residues ◽  
Surface Dynamics ◽  
Transmembrane Helices ◽  
Nmr Studies ◽  
Specific Manner ◽  
Local Conformations ◽  
C Nmr

We demonstrate here how dynamic as well as conformational features of bacteriorhodopsin (bR) in purple membrane (PM) as a typical membrane protein are revealed by extensive13C NMR studies on [3-13C]-, [2-13C]-, [1-13C]Ala or [1-13C]Val-labeled bR and a variety of site-directed mutants. A number of13C NMR peaks were well-resolved for [3‒13C]Ala‒ and [1-13C]Val-bR under the condition of fully hydrated PM at ambient temperature and assigned to individual amino-acid residues, initially by regio-specific manner with reference to the data of the conformation-dependent displacements of peaks from model polypeptides and subsequently by site-specific manner with reference to the specifically reduced peak-intensities of site-directed mutant as compared with those of wild type. It is noticeable that the revealed bR structure at ambient temperature by13C NMR is not static as anticipated from the data of diffraction studies at cryo-temperature but is dynamically heterogeneous undergoing motional fluctuations with various frequencies (102–108Hz) depending upon the domains of interest. We further applied this approach to reveal how charged state of surface residues, especially at the side-chain of exracellular Glu residues (Glu 194 and 204), could be transmitted to the inner part of the helices such as Ala 53, 84, and 215 to alter their local conformations of transmembrane helices near at the Schiff base through side-chain interactions. We also analyzed how information of the protonation at Asp 85 from helix C is initially transmitted to helices B (Val 49) and G (Val 213) though modified helix‒helix interactions through the side-chains of Arg 82.

Spectroscopy of chromium compounds in molten salts

1970 ◽  
Vol 48 (1) ◽  
pp. 55-58 ◽  
Author(s):  
H. C. Brookes ◽  
S. N. Flengas
Keyword(s):  
Absorption Spectrum ◽  
Ambient Temperature ◽  
Absorption Spectra ◽  
Molten Salts ◽  
Temperature Measurements ◽  
Dilute Solutions ◽  
Heats Of Solution ◽  
Chromium Compounds

Modifications to the Hitachi Perkin–Elmer 139 ultraviolet–visible spectrophotometer are described which enable absorption spectra of molten salts to be measured to 865 °C. The instrument can be readily reconverted for ambient temperature measurements. The solubilities and the limiting heats of solution of Ag2CrO4 and PbCrO4 in equimolar NaNO3–KNO3 have been measured spectrophotometrically from 250 to 350 °C. The absorption spectrum of dilute solutions of Cr(III) in CsCl has been measured, the octahedral CrCl63− being present in solution at 700 °C.

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