Structure and bonding in neutral and cationic 14-electron gold alkyne pi complexes.
Cyclododecyne (5) as a prototype unstrained alkyne was coordinated to either the neutral [AuCl] fragment or to two different cationic [Au(NHC)](+) entities (NHC = N-heterocyclic carbene), and the resulting complexes 6, 8, and 10 were characterized by X-ray crystallography and NMR spectroscopy. Since the structure of cyclododecyne in the solid state could also be obtained after in situ crystallization, a comparison was possible that provides insights into structural changes imposed on the alkyne by the different gold fragments. These data are interpreted on the basis of a DFT analysis of the bonding situation in the individual compounds, which provides insights into the very first elementary step common to many gold-catalyzed transformations.
Flügge
Susanne
S
Max-Planck-Institut für Kohlenforschung, 45470 Mülheim an der Ruhr (Germany), Fax: (+49) 208-306-2994.
Anoop
Anakuthil
A
Max-Planck-Institut für Kohlenforschung, 45470 Mülheim an der Ruhr (Germany), Fax: (+49) 208-306-2994.
Goddard
Richard
R
Max-Planck-Institut für Kohlenforschung, 45470 Mülheim an der Ruhr (Germany), Fax: (+49) 208-306-2994.
Thiel
Walter
W
Max-Planck-Institut für Kohlenforschung, 45470 Mülheim an der Ruhr (Germany), Fax: (+49) 208-306-2994.
Fürstner
Alois
A
Max-Planck-Institut für Kohlenforschung, 45470 Mülheim an der Ruhr (Germany), Fax: (+49) 208-306-2994.