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Substituent effects on magnetic non‐ equivalence in acetals
Author(s) -
Rattet Lana S.,
Goldstein J. H.
Publication year - 1969
Publication title -
organic magnetic resonance
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0030-4921
DOI - 10.1002/mrc.1270010308
Subject(s) - electronegativity , halogen , substituent , methylene , chemistry , spectral line , proton magnetic resonance , chemical shift , symmetry (geometry) , atom (system on chip) , crystallography , computational chemistry , stereochemistry , physics , medicinal chemistry , nuclear magnetic resonance , mathematics , organic chemistry , quantum mechanics , alkyl , geometry , computer science , embedded system
The proton and 13 CH satellite spectra of five diethyl haloacetals have been analyzed and their spectral parameters obtained. The parameters for the ethoxy methylene protons indicate the extent of their magnetic nonequivalence. It has been found that these parameters are dependent on the degree of halogen substitution in the group Z, which is bonded to the central carbon atom, and correlate well with the corresponding group electronegativity values, a′ z , proposed by Huheey. The parallel behavior of the methylenic J (CH) and chemical shifts indicates that a primarily through‐bond mechanism is responsible for propagation of both the electronic and symmetry effects observed. Transmission factors calculated from the spectral data agree with independent estimates reasonably well, thus supporting the conclusions reached here.