PMID- 22263528
OWN - NLM
STAT- MEDLINE
DCOM- 20120605
LR  - 20131121
IS  - 1520-6904 (Electronic)
IS  - 0022-3263 (Linking)
VI  - 77
IP  - 3
DP  - 2012 Feb 3
TI  - Kinetic solvent effects on hydrogen abstraction from phenol by the cumyloxyl 
      radical. Toward an understanding of the role of protic solvents.
PG  - 1267-72
LID - 10.1021/jo201454c [doi]
AB  - A time-resolved kinetic study of the hydrogen atom abstraction reactions from 
      phenol by the cumyloxyl radical (CumO(*)) was carried out in different solvents. 
      The hydrogen atom abstraction rate constant (k(H)) was observed to decrease by 
      almost 3 orders of magnitude on going from isooctane to MeOH. In TFE, MeCN/H(2)O 
      2:1, and MeOH, the measured k(H) values were lower than expected on the basis of 
      the Snelgrove-Ingold (SI) equation that correlates log k(H) to the solvent 
      hydrogen bond acceptor (HBA) ability parameter beta(2)(H). As these solvents also 
      act as hydrogen bond donors (HBDs), we explored the notion that a more thorough 
      description of solvent effects could be provided by including a solvent HBD 
      ability term, alpha(2)(H), into the SI equation via beta(2)(H)(1 + alpha(2)(H)). The 
      inclusion of such a term greatly improves the fitting for TFE, MeCN/H(2)O 2:1, 
      and MeOH but at the expense of that for tertiary alkanols. This finding suggests 
      that, for the reaction of CumO(*) with phenol, the HBA and HBD abilities of both 
      the solvent and the substrate could be responsible for the observed KSEs. but 
      this requires that primary and tertiary alkanols exhibit different solvation 
      behaviors. Possible explanations for this different behavior are explored.
FAU - Bietti, Massimo
AU  - Bietti M
AD  - Dipartimento di Scienze e Tecnologie Chimiche, Universita Tor Vergata, Via della 
      Ricerca Scientifica, 1 I-00133 Rome, Italy. bietti@uniroma2.it
FAU - Salamone, Michela
AU  - Salamone M
FAU - DiLabio, Gino A
AU  - DiLabio GA
FAU - Jockusch, Steffen
AU  - Jockusch S
FAU - Turro, Nicholas J
AU  - Turro NJ
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, Non-P.H.S.
DEP - 20120120
PL  - United States
TA  - J Org Chem
JT  - The Journal of organic chemistry
JID - 2985193R
RN  - 0 (Benzene Derivatives)
RN  - 0 (Free Radicals)
RN  - 0 (Phenols)
RN  - 0 (Solvents)
RN  - 7YNJ3PO35Z (Hydrogen)
SB  - IM
MH  - Benzene Derivatives/*chemistry
MH  - Free Radicals/*chemistry
MH  - Hydrogen/*chemistry
MH  - Kinetics
MH  - Phenols/*chemistry
MH  - Solvents/*chemistry
EDAT- 2012/01/24 06:00
MHDA- 2012/06/06 06:00
CRDT- 2012/01/24 06:00
PHST- 2012/01/24 06:00 [entrez]
PHST- 2012/01/24 06:00 [pubmed]
PHST- 2012/06/06 06:00 [medline]
AID - 10.1021/jo201454c [doi]
PST - ppublish
SO  - J Org Chem. 2012 Feb 3;77(3):1267-72. doi: 10.1021/jo201454c. Epub 2012 Jan 20.