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Metal Olefin Complexes: Revisiting the Dewar − Chatt − Duncanson Model and Deriving Reactivity Patterns from Carbon‐13 NMR Chemical Shift
Author(s) -
Gordon Christopher P.,
Andersen Richard A.,
Copéret Christophe
Publication year - 2019
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.201900151
Subject(s) - olefin fiber , chemistry , reactivity (psychology) , protonolysis , ligand (biochemistry) , metal , catalysis , carbon 13 nmr , atomic orbital , computational chemistry , stereochemistry , organic chemistry , electron , medicine , biochemistry , physics , alternative medicine , receptor , pathology , quantum mechanics
Metal olefin complexes that are ubiquitous intermediates in catalysis are investigated by a detailed analysis of their 13 C‐NMR chemical shift tensors. This analysis allows evidencing specific electronic features, namely the olefin‐to‐metal σ ‐donation and the metal‐to‐olefin π ‐backdonation as proposed in the Dewar−Chatt−Duncanson model. Apart from these interactions, the chemical shift tensor analysis reveals an additional ligand‐to‐metal π ‐donation of the olefin σ (C=C) orbital in systems with suitably oriented vacant d‐orbitals. This interaction which is not accounted for in the Dewar−Chatt−Duncanson model explains the reactivity of this type of metal olefin complexes towards oxidative cyclization (olefin insertion) and protonolysis.