AN INVESTIGATION OF TAUTOMERIC EQUILIBRIA BY MEANS OF MASS SPECTROMETRY

被引:60
作者
ZAMIR, L
JENSEN, BS
LARSEN, E
机构
[1] Chemistry Department, Danish Atomic Energy Commission Research Establishment, Risö
[2] Chem Dept., Yale University, New Haven, Connecticut
来源
ORGANIC MASS SPECTROMETRY | 1969年 / 2卷 / 01期
关键词
D O I
10.1002/oms.1210020106
中图分类号
O62 [有机化学];
学科分类号
070303 ; 081704 ;
摘要
Changes in the mass spectra with inlet temperature were used in this work to demonstrate the dependence of keto‐enol tautomerism of acetylacetone, 3‐methyl acetylacetone and 3‐allyl acetylacetone on temperature. The largest dependence of temperature were shown by the ion [M  42]+. arising from a McLafferty type rearrangement and by the ion [M  Me]+ resulting from simple α‐cleavage. The ion [M  42]+. peak increases with the temperature of the inlet system while the ion [M  Me]+ peak decreases. By assuming that the ion [M  42]+. represents the keto form and that the ion [M  Me]+ represents the cis‐enol form (stabilized by the hydrogen bond) one sees that the direction of the intensity variation of these peaks with temperature is in accord with the expected change of keto‐enol tautomerism with temperature. A quantitative correlation on the basis of the above assumptions is also approached. Recording of the mass spectra of these three β‐diketones at different energies of the incident electrons enables us to estimate whether or not the particular ions present in the mass spectra result from energetically favourable processes. The variation of the intensities of the peaks with the temperature of the inlet at different electron energies is also discussed. Copyright © 1969 John Wiley & Sons, Ltd.
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页码:49 / &
相关论文
共 15 条
[1]   AN NMR STUDY OF KETO-ENOL TAUTOMERISM IN BETA-DIKETONES [J].
ALLEN, G ;
DWEK, RA .
JOURNAL OF THE CHEMICAL SOCIETY B-PHYSICAL ORGANIC, 1966, (02) :161-&
[2]   REARRANGEMENT REACTIONS OF SOME SIMPLE KETONES AND ESTERS UPON ELECTRON IMPACT [J].
BOWIE, JH ;
GRIGG, R ;
WILLIAMS, DH ;
LAWESSON, SO ;
SCHROLL, G .
CHEMICAL COMMUNICATIONS, 1965, (17) :403-&
[3]   STUDIES IN MASS SPECTROMETRY .9. MASS SPECTRA OF BETA-DIKETONES [J].
BOWIE, JH ;
WILLIAMS, DH ;
LAWESSON, SO ;
SCHROLL, G .
JOURNAL OF ORGANIC CHEMISTRY, 1966, 31 (05) :1384-&
[4]  
BUDZIKIEWICZ H, 1967, MASS SPECTROMETRY OR
[5]  
BUDZIKIEWICZ J, 1965, CHEM IND LONDON, P1697
[7]   MASS SPECTROMETRY IN STRUCTURAL AND STEREOCHEMICAL PROBLEMS .122. POSSIBLE OPERATION OF TAUTOMERISM BEFORE AND AFTER ELECTRON-IMPACT INDUCED FRAGMENTATION OF MOLECULAR IONS [J].
MACLEOD, JK ;
THOMSON, JB ;
DJERASSI, C .
TETRAHEDRON, 1967, 23 (05) :2095-&
[8]   THE EFFECT OF SOLVENTS ON TAUTOMERIC EQUILIBRIA [J].
POWLING, J ;
BERNSTEIN, HJ .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1951, 73 (09) :4353-4356
[9]   NUCLEAR MAGNETIC RESONANCE MEASUREMENTS IN SOLUTIONS OF ACETYLACETONE - THE EFFECT OF SOLVENT INTERACTIONS ON THE TAUTOMERIC EQUILIBRIUM [J].
REEVES, LW .
CANADIAN JOURNAL OF CHEMISTRY-REVUE CANADIENNE DE CHIMIE, 1957, 35 (11) :1351-1365
[10]  
SCHAMP N, 1966, B SOC CHIM BELG, V75, P539