We provide a rigorous model-free definition and a detailed theoretical analysis of the electron- charge displacements making up the donation and back-donation compo- nents of the Dewar–Chatt–Duncanson model in some realistic catalytic inter- mediates of formula L–AuI–S in which L is an N-heterocyclic carbene or Cl and S is an eta2-coordinated substrate containing a C C multiple bond. We thus show, contrary to a widely held view, that the gold substrate bond is characterized by a large p back-donation component that is comparable to, and often as large as, the s donation. The back-donation is found to be a highly tunable bond component and we analyze its relationship with the nature of the auxiliary ligand L and with structural (interdependent) factors such as metal–substrate bond lengths and carbon pyramidalization.
On the Dewar-Chatt-Duncanson model for catalytic gold(I) complexes
BELPASSI, LEONARDO;TARANTELLI, Francesco
2010
Abstract
We provide a rigorous model-free definition and a detailed theoretical analysis of the electron- charge displacements making up the donation and back-donation compo- nents of the Dewar–Chatt–Duncanson model in some realistic catalytic inter- mediates of formula L–AuI–S in which L is an N-heterocyclic carbene or Cl and S is an eta2-coordinated substrate containing a C C multiple bond. We thus show, contrary to a widely held view, that the gold substrate bond is characterized by a large p back-donation component that is comparable to, and often as large as, the s donation. The back-donation is found to be a highly tunable bond component and we analyze its relationship with the nature of the auxiliary ligand L and with structural (interdependent) factors such as metal–substrate bond lengths and carbon pyramidalization.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
