ISSN:
0749-1581
Keywords:
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Aromatic 13C chemical shifts are reported for an extensive set (15 common substituents) of 1,3-disubstituted benzenes measured at low concentration in deuteriochloroform. The substituent chemical shift data show systematic non-additivity. Data for the para- and two meta-positions to the variable substituent were analysed using the recently developed non-linear resonance (DSP-NLR) and standard (DSP) dual substituent parameter equations. It is shown for these positions that mutual substituent interaction is responsible for the non-additive shifts and that (a) this interaction has both an inductive (polar) and a resonance component, even for meta-oriented substituents, and (b) the shift-charge ratio term extends past the ipso-position. These results are discussed in terms of local paramagnetic shielding contributions to 13C shifts.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/mrc.1260241004
