Classification of Low-Energy Conformations of Met-Enkephalin in the Gas Phase and in a Model Solvent Based on the Extended Scaled Particle Theory

1999 ◽  
Vol 72 (8) ◽  
pp. 1717-1729 ◽  
Author(s):  
Ayori Mitsutake ◽  
Masayuki Irisa ◽  
Yuko Okamoto ◽  
Fumio Hirata
Keyword(s):  
Gas Phase ◽  
Low Energy ◽  
Scaled Particle Theory ◽  
Particle Theory ◽  
Low Energy Conformations

Low Energy Conformations and Gas-Phase Acidity and Basicity of Pyrrolysine

2014 ◽  
Vol 118 (34) ◽  
pp. 7085-7095 ◽  
Author(s):  
Lingbiao Meng ◽  
Zhuo Wang ◽  
Jicheng Zhang ◽  
Minjie Zhou ◽  
Weidong Wu
Keyword(s):  
Gas Phase ◽  
Low Energy ◽  
Gas Phase Acidity ◽  
Acidity And Basicity ◽  
Low Energy Conformations

scholarly journals Use of scaled-particle theory in the assessment of the Ph4As+/Ph4B− assumption for single ions

1979 ◽  
Vol 57 (1) ◽  
pp. 71-76 ◽  
Author(s):  
Michael H. Abraham ◽  
Asadollah Nasehzadeh
Keyword(s):  
Free Energy ◽  
Recent Work ◽  
Scaled Particle Theory ◽  
Cavity Formation ◽  
Energy Term ◽  
Free Energies ◽  
Particle Theory ◽  
Novel Method ◽  
Energy Of Interaction ◽  
Solvent Molecules

A novel method for the assessment of the Ph4As+/Ph4B− assumption for free energies of transfer of single ions has recently been suggested by Treiner, and used by him to deduce that the assumption is not valid for transfers between water, propylene carbonate, sulpholane, dimethylsulphoxide, N-methyl-2-pyrrolidone, and perhaps also dimethylformamide. The basis of the method is the estimation of the free energy of cavity formation by scaled-particle theory, together with the hypothesis that the free energy of interaction of Ph4As+ (or Ph4B−) with solvent molecules is the same in all solvents, ΔGt0(int) = 0. It is shown in the present paper that (a) whether or not the Ph4As+/Ph4B− assumption applies to transfer to a given solvent depends on which other solvent is taken as the reference solvent in Treiner's method, (b) the calculation of the cavity free energy term by scaled-particle theory and by the theory of Sinanoglu – Reisse – Moura Ramos (SRMR) yields values so different that the method cannot be considered reliable, (c) the calculation of cavity enthalpies and entropies for Ph4As+ or Ph4B− by scaled-particle theory yields results that are chemically not reasonable, (d) the hypothesis that ΔGt0(int) = 0 conflicts with SRMR theory, and (e) the conclusions reached by Treiner are not in accord with recent work that in general supports the Ph4As+/Ph4B− assumption for solvents that are rejected by Treiner.

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