Results 221 to 230 of about 26,157 (280)

Hydrogen-Bonded Encapsulation Complexes in Protic Solvents

Journal of the American Chemical Society, 2004
We describe here the behavior of the hydrogen-bonded capsule 1.1 and its complexes in protic solvents. The kinetics and thermodynamics of the encapsulation process were determined through conventional (1)H NMR methods. The enthalpies and entropies of encapsulation are both positive, indicating a process that liberates solvent molecules.
Toru, Amaya, Julius, Rebek
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Proton solvation in protic and aprotic solvents

Journal of Computational Chemistry, 2016
Protonation pattern strongly affects the properties of molecular systems. To determine protonation equilibria, proton solvation free energy, which is a central quantity in solution chemistry, needs to be known. In this study, proton affinities (PAs), electrostatic energies of solvation, and pKA values were computed in protic and aprotic solvents.
Emanuele, Rossini, Ernst-Walter, Knapp
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On the Roles of Protic Solvents in Imidazolidinone‐Catalyzed Transformations

Angewandte Chemie International Edition, 2011
Step by step: The effect of protic solvents on the rate and stereochemical outcome of the imidazolidinone-catalyzed Diels–Alder cycloaddition was rationalized. The following picture emerges: the solvent accelerates iminium ion formation (step 1), the Diels–Alder cycloaddition is reversible (step 2), and the solvent intercepts the iminium ion adduct ...
Brazier, John B., Jones, Kevin M., Platts, James A., Tomkinson, Nicholas C.O.   +3 more
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Anion solvation in protic solvents

Journal of the Chemical Society, Chemical Communications, 1977
Spectroscopic evidence is advanced in favour of the concept of continuous hydrogen-bonding from anions into bulk solvent with no intervention of an intermediate structureless region.
Susan E. Jackson, Imants M. Strauss, Martyn C. R. Symons   +2 more
openaire   +1 more source

Solvent-mediated molar conductivity of protic ionic liquids

Physical Chemistry Chemical Physics, 2015
The molar conductivity, Λm, of protic ionic liquids (PILs) in molecular solvents is measured at 298.15 K.
Sachin, Thawarkar, Nageshwar D, Khupse, Anil, Kumar   +2 more
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Nucleofugality and Nucleophilicity of Fluoride in Protic Solvents

The Journal of Organic Chemistry, 2012
A series of p-substituted benzhydryl fluorides (diarylfluoromethanes) were prepared and subjected to solvolysis reactions, which were followed conductometrically. The observed first-order rate constants k(1)(25 °C) were found to follow the correlation equation log k(1)(25 °C) = s(f)(N(f) + E(f)), which allowed us to determine the nucleofuge-specific ...
Christoph, Nolte, Johannes, Ammer, Herbert, Mayr   +2 more
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Photophysical properties of safranine O in protic solvents

Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2004
Spectroscopic and photophysical properties of safranine O (Sf) were investigated in binary water/solvent mixtures. It was found that these properties are strongly solvent-dependent. A blue shift is observed for both the ground-state absorption and the triplet-triplet main absorption band when the solvent polarity augments.
María L, Gómez, Carlos M, Previtali, Hernán A, Montejano   +2 more
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New protic salts of aprotic polar solvents

Tetrahedron Letters, 2004
Abstract Aprotic polar solvents such as DMF, acetonitrile or DMSO can be protonated to form stable triflate salts when treated with triflic acid. The reaction of the same solvents with N , N -bis(trifluoromethanesulfonyl)imide led to the isolation of the corresponding N , N -bis(trifluoromethanesulfonyl)imide salts.
Isabelle Favier, Elisabet Duñach
openaire   +1 more source

Rotational diffusion in aprotic and protic solvents

Chemical Physics, 1978
Abstract We present the orientational relaxation times in protic and aprotic solvents for rose bengal in its lowest excited singlet state. The method uses a mode locked dye laser for polarized excitation, and time correlated single photon counting for determination of the time resolved polarized fluorescence.
Kenneth G. Spears, Laurence E. Cramer
openaire   +1 more source