
TY  - JOUR
A1  - Hush, NS 
A1  - Livett, MK 
A1  - Peel, JB 
A1  - Willett, GD 
T1  - Variable-Temperature Ultraviolet Photoelectron-Spectroscopy of the Keto-Enol Tautomers of Pentane-2,4-Dione
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1987
VL  - 40
IS  - 3
SP  - 599
EP  - 609
KW  - 
UR  - https://doi.org/10.1071/CH9870599 
N2  - The HeI photoelectron spectra of pentane-2,4-dione measured at various temperatures have been subjected to a spectrum-stripping technique to enable isolation of the complete HeI photoelectron spectra of the keto and enol tautomers. The resulting spectrum-stripping coefficients allow evaluation of the enolization equilibrium constant at each temperature and subsequently the enthalpy of enolization. Interpretation of the photoelectron spectra is achieved with the use of ab  initio  molecular orbital calculations. Photoionization of non-bonding oxygen, and &#960; -type electrons, contribute to the low ionization energy region of the spectrum, with a &#960;CC < no- <&#960;CO ordering for the enol tautpmer , and no- < no+ < &#960;CO+ for the keto tautomer . Because of different electronic relaxation effects, &#8710;SCF calculations are required to predict correctly the observed &#960;CC/no- spacing for the enol tautomer. 
ER  -

