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Principal component analysis of the 13 C NMR shifts of norbornyl derivatives
Author(s) -
Tostes J. G. Ribeiro,
Seidl P. R.,
Bruns R. E.
Publication year - 1989
Publication title -
magnetic resonance in chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0749-1581
DOI - 10.1002/mrc.1260270314
Subject(s) - 2 norbornyl cation , chemistry , steric effects , substituent , chemical shift , ring (chemistry) , molecule , principal component analysis , stereochemistry , carbon 13 nmr , component (thermodynamics) , computational chemistry , organic chemistry , physics , artificial intelligence , computer science , thermodynamics
Abstract Principal component analysis was applied to the 13 C NMR chemical shifts of the seven carbon atoms of the norbornyl framework for 75 molecules. Two two‐dimensional principal component projections are shown to be sufficient to distinguish the main electronic and steric substituent effects contributing to these shifts. These effects allow a comparison of the (three‐, four‐ and five‐membered) ring and non‐ring substituents and their influence on the shifts of carbon atoms of the norbornyl framework. Four classes of molecules, each with characteristic chemical behaviour, are identified. Exo ‐ endo class discrimination and exo ‐ endo patterns of isomer pairs are emphasized, especially with regard to cyclic substituents on norbornyl systems.