Thermodynamic studies of protein-salt interaction. Phycocyanin-tetrabutylammonium bromide and -tetraethylammonium bromide

1977 ◽  
Vol 81 (2) ◽  
pp. 125-129 ◽  
Author(s):  
Chang-Hwei Chen ◽  
Donald S. Berns
Keyword(s):  
Tetrabutylammonium Bromide ◽  
Tetraethylammonium Bromide ◽  
Thermodynamic Studies

Calixarene Phosphorylation: Cation Control of Reaction Pathways

1993 ◽  
Vol 46 (11) ◽  
pp. 1673 ◽  
Author(s):  
LT Byrne ◽  
JM Harrowfield ◽  
DCR Hockless ◽  
BJ Peachey ◽  
BW Skelton ◽  
...  
Keyword(s):  
Phase Transfer ◽  
Tetrabutylammonium Bromide ◽  
Crystal Structure Analysis ◽  
Bidentate Ligand ◽  
Tetraethylammonium Bromide ◽  
Cone Conformation ◽  
Formation Reaction ◽  
Partial Cone ◽  
Major Reaction Product ◽  
Major Reaction

The hydroxide ion catalysed phosphorylation of p-t- butylcalix [4] arene by diethyl chlorophosphate under heterogeneous conditions shows a marked sensitivity to the nature of the phase transfer catalyst used. Thus, substitution of tetraethylammonium bromide for the tetrabutylammonium bromide prescribed for the synthesis of the calixarene tetraphosphate leads to a major reaction product becoming a bis (phosphate) in which the calixarene binds as a unidentate ligand to one phosphorus and as a bidentate ligand to the other. An X-ray crystal structure analysis on this new compound shows the calixarene to adopt a somewhat distorted 'cone' conformation with an unusual orientation of one of the t-butyl substituents into the cone cavity. It also reveals that a significant diastereoselectivity must operate in the formation reaction. The only other reaction product detected in this system appears to be the calixarene tetraphosphate in a partial cone conformation.

scholarly journals Activation of sub 2 nm Water Soluble and Insoluble Standard Ions with Saturated Vapors of Butanol in a Boosted TSI Ultrafine CPC.

Atmosphere ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 665 ◽  
Author(s):  
Attoui ◽  
Kangasluoma
Keyword(s):  
Water Solubility ◽  
Detection Efficiency ◽  
Aerosol Particles ◽  
Tetrabutylammonium Bromide ◽  
Water Soluble ◽  
Tetraethylammonium Bromide ◽  
Particle Counter ◽  
Condensation Particle Counter ◽  
Singly Charged ◽  
Nm Range

Tetraheptylammonium bromide (THABr), tetrabutylammonium bromide (TBABr) and tetraethylammonium bromide (TEABr) dissolved in methanol or water methanol mixtures (~ 1mM) produce via positive electrospray atomization and high resolution classification electrical classification standard clean ions (monomer and dimer) which are singly charged. THABr is hydrophobic and insoluble in water, TBABr and TEABr are hygroscopic and water soluble (0.6 and 2.8 kg/l respectively). These ions are used to study the effect of hygroscopicity on the activation of aerosol particles in the sub 2 nm range via the detection efficiency measurement of a boosted ultrafine TSI condensation particle counter (3025A). Water solubility of particles seems to play a role in the activation and growth with butanol vapor in the CPC (condensation particle counter) independently of the size.

scholarly journals On a Ti Study of Molecular Motion in Some Tetra Substituted Ammonium Halides

1979 ◽  
Vol 34 (11) ◽  
pp. 1296-1300
Author(s):  
Fevzi Köksal
Keyword(s):  
Molecular Motion ◽  
Relaxation Times ◽  
Tetrabutylammonium Bromide ◽  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
Tetraethylammonium Bromide ◽  
Tetraethylammonium Chloride ◽  
Spin Lattice ◽  
Ammonium Halides ◽  
Tetramethylammonium Bromide

The spin-lattice relaxation times of tetramethylammonium bromide (CH3)4NBr , iodide (CH3)4NI, tetraethylammonium chloride (CH3CH2)4NCl, bromide (CH3CH2)4NBr, iodide (CH3CH2)4NI , tetrapropylammonium iodide [CH3(CH2)2]4NI, tetrabutylammonium bromide [CH3(CH2)3]4NBr, iodide [CH3(CH2)3]4NI, tetraheptylammonium bromide [CH3(CH2)6]4NBr and iodide [CH3(CH2)6]4NI were measured at 60 MHz in the temperature interval 100 K to near the melting points. Two minima of T1 were observed for tetramethylammonium halides, for tetraethylammonium bromide and iodide and for tetrapropylammonium iodide. The minima in T1 were attributed to CH3 group reorientations and reorientations of the tetramethyl, ethyl and propylammonium cations. The activation energies of the processes were determined

Viscosities of some tetraalkylammonium bromides in 2-ethoxyethanol at 308.15, 313.15, 318.15, and 323.15 K

2005 ◽  
Vol 83 (5) ◽  
pp. 499-504 ◽  
Author(s):  
Purushottam Haldar ◽  
Bijan Das
Keyword(s):  
Transition State ◽  
Tetrabutylammonium Bromide ◽  
Viscosity Data ◽  
Tetraethylammonium Bromide ◽  
Tetraalkylammonium Ions ◽  
Free Energy Of Activation ◽  
Tetrapropylammonium Bromide ◽  
Ionic Contribution ◽  
Tetraalkylammonium Ion ◽  
B Coefficients

The viscosities of the solutions of tetraethylammonium bromide (Et4NBr), tetrapropylammonium bromide (Pr4NBr), tetrabutylammonium bromide (Bu4NBr), tetrapentylammonium bromide (Pen4NBr), and tetraheptylammonium bromide (Hep4NBr) in 2-ethoxyethanol have been reported at 308.15, 313.15, 318.15, and 323.15 K. The viscosity data have been analyzed by the Jones–Dole equation for the associated electrolytes to evaluate the viscosity B coefficients of the electrolytes. These data have also been analyzed by the transition-state treatment to obtain the contribution of the solutes to the free energy of activation for viscous flow of the solution. The viscosity of the solvent is found to be greatly modified by the presence of all of the tetraalkylammonium ions investigated. Moreover, the tetraalkylammonium ions are found to be unsolvated in 2-ethoxyethanol solutions, they behave neither as structure-breaker nor as structure-maker and the formation of the transition state is made less favorable in their presence.Key words: viscosity, electrolytes, tetraalkylammonium ion, 2-ethoxyethanol, ionic contribution, solvation, transition-state treatment.

Volumetric studies of ion solvation in propylene carbonate + N,N-dimethylformamide electrolyte solutions

2003 ◽  
Vol 81 (4) ◽  
pp. 307-314 ◽  
Author(s):  
Yang Zhao ◽  
Jianji Wang ◽  
Xiaopeng Xuan ◽  
Ruisen Lin
Keyword(s):  
Propylene Carbonate ◽  
Tetrabutylammonium Bromide ◽  
Partial Molar Volumes ◽  
Lewis Base ◽  
Ion Solvation ◽  
Scaled Particle Theory ◽  
Solvent Mixtures ◽  
Tetraethylammonium Bromide ◽  
Molar Volumes ◽  
Tetraalkylammonium Cations

Apparent molar volumes V2,ϕ and standard partial molar volumes V°2,ϕ for tetraethylammonium bromide (Et4NBr), tetrapropylammonium bromide (Pr4NBr), tetrabutylammonium bromide (Bu4NBr), and tetrahexylammonium bromide (Hex4NBr) have been determined at 298.15 K from precise density measurements in solvent mixtures of propylene carbonate (PC) with N,N-dimethylformamide (DMF). Combined with our previous data for LiClO4 and LiBr in the same solvents, ionic molar volumes of Li+, Et4N+, Pr4N+, Bu4N+, Hex4N+, and related anions have been deduced from the extrapolation method suggested by Conway and co-workers. It is shown that the molar volumes of these cations are quite independent of the nature of the solvent and the composition of the solvent mixtures, in contrast to those of ClO4– and Br– anions. This suggests that the Lewis-base-type solvents with similar molecular volumes have similar interactions with Li+. The constancy in partial molar volume for tetraalkylammonium ions provides helpful evidence for the lack of solvation of large tetraalkylammonium cations in organic solvents. These findings have been interpreted using scaled-particle theory. The results are discussed in terms of ion solvation, packing effects of solvent molecules in the solvation shell, and the electrostriction of solvents.Key words: ionic volumes, propylene carbonate, N,N-dimethylformamide, solvent mixtures, solvation, lithium batteries.

Aggregation Behavior and Thermodynamic Studies of Hydrotropes: A Review

2020 ◽  
Vol 57 (3) ◽  
pp. 192-202 ◽  
Author(s):  
Akash D. Patel ◽  
Meghal A. Desai
Keyword(s):  
Aggregation Behavior ◽  
Thermodynamic Studies

Thermodynamic Studies of SN38 Hydrolysis in the Presence of Human and Bovine Serum Albumin

2011 ◽  
Vol 1 (2) ◽  
pp. 140-151 ◽  
Author(s):  
Balasubramanian Sivakumar ◽  
Rishi Thakur ◽  
Sasank Kunadharaju ◽  
Michalakis Savva
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Bovine Serum ◽  
Thermodynamic Studies

The effect of cation concentration on the nitrogen splitting constant of nitroxide free radicals

1990 ◽  
Vol 55 (10) ◽  
pp. 2377-2380
Author(s):  
Hamza A. Hussain
Keyword(s):  
Hydrogen Peroxide ◽  
Hydrogen Bonding ◽  
Free Radicals ◽  
Esr Spectroscopy ◽  
The Other ◽  
Tetraethylammonium Bromide ◽  
Splitting Constant ◽  
The One ◽  
Positively Charged ◽  
Two Equilibria

Nitroxide free radicals prepared from diethylamine, piperidine and pyrrolidine by oxidation with hydrogen peroxide were studied by ESR spectroscopy. The changes in the 14N splitting constant (aN) caused by the addition of KBr or tetraethylammonium bromide were measured in dependence on the concentration of the ions. For diethylamine nitroxide and piperidine nitroxide, the results are discussed in terms of two equilibria: the one, involving the anion, is associated with a gain or loss of hydrogen bonds to the nitroxide oxygen atom, the other is associated with the formation of solvent shared units involving the cation, which results in changes in the hydrogen bonding strenght. The large increase in the aN value in the case of pyrrolidine nitroxide is explained in terms of an interaction from one side of the positively charged N atom; the increase in aN in the case of diethylamine and piperidine nitroxides is explained in terms of interactions with both sides of the positively charged N atom.

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