ISSN:
0749-1581
Keywords:
13C and 19F chemical shifts
;
Multisubstituted methanes
;
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The 13C and 19F (when appropriate) chemical shifts of a variety of di-, tri- and tetrasubstituted methanes of the type CH2XCOOEt (I), CHXYCOOEt (II) and CXYZCOOEt (III), where the substituents X, Y and Z are F, Br, OEt, OPh, SEt, SPh and NO2, were determined. The prediction of the observed C-α chemical shifts of I, II and III based on the simple additivity of substituent effects in monosubstituted methanes [MeX; SCS(IV)] is not satisfactory, although those of I are well correlated with SCS (IV). The C-α chemical shifts of II and III can be correlated in terms of the multi-parameter analysis of individual SCS (I), the difference between δ (CH2XCOOEt) and δ (CH3COOEt). The origin of the chemical shifts is discussed. The 19F chemical shifts of I, II and III were also satisfactorily analysed in terms of σI and σR0.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/mrc.1260300111
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