scholarly journals Mechanistic Insights into RNA Transphosphorylation from Kinetic Isotope Effects and Linear Free Energy Relationships of Model Reactions

2014 ◽  
Vol 20 (44) ◽  
pp. 14336-14343 ◽  
Author(s):  
Haoyuan Chen ◽  
Timothy J. Giese ◽  
Ming Huang ◽  
Kin-Yiu Wong ◽  
Michael E. Harris ◽  
...  
2005 ◽  
Vol 83 (9) ◽  
pp. 1606-1614 ◽  
Author(s):  
Salai Cheettu Ammal ◽  
Hiroshi Yamataka

Ab initio calculations at the MP2/6-31G* level and density functional theory (B3LYP/6-311+G**) calculations have been performed on acid-catalyzed ionizations of substituted neophyl alcohols to investigate whether a variation of the transition-state (TS) structure is reflected in the kinetic isotope effects (KIE) and linear free energy relationship. The effect of substituents on KIEs, TS structures, and activation and reaction energies was calculated. This study revealed that a curved Brønsted-type plot could arise for a single-step process from the variation of TS structure with the substituent, whereas the Hammett plots with a dual-parameter treatment can not detect such TS variation. The variation of KIEs at various positions of neophyl alcohol reflects the variation of TS structures in a manner consistent with the More O'Ferrall – Jencks type reaction diagram analyses.Key words: transition-state variation, substituent effect, kinetic isotope effect, linear free energy relationship.


2005 ◽  
Vol 83 (9) ◽  
pp. 1667-1719 ◽  
Author(s):  
J MW Scott

The hydrolyses of a series of organic halides, nitrates, sulphonates, and perchlorates are examined from the standpoint of thermodynamics, kinetics, temperature dependence, isotope effects, the Kurz equation, and the Guthrie linear free energy relationship. The thermodynamics of several definite bimolecular displacements are also examined. Some mechanistic revisions are suggested to reach an improved accommodation with the experimental observations.Key words: kinetics, thermodynamics, hydrolytic displacements, mechanism, ionic displacements, nucleofugality, linear free energy relationships.


2007 ◽  
Vol 42 (11) ◽  
pp. 1496-1503 ◽  
Author(s):  
Eduardo A. Solano Espinoza ◽  
Elena Stashenko ◽  
Jairo Martínez ◽  
Uriel Mora ◽  
Vladimir Kouznetsov

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