4PM 21 January 2004, Physics Lecture Theatre, University of Warwick
Dr John E McGrady, University of York
Adventures with agostics: complex equilibria in alkyl niobium compounds.
This talk will present a combined experimental and computational investigation of the agostic bonding in a family of complexes with general formula Tp*NbCl ( MeC ß CMe ) R, where the alkyl substituent, R, can be either acyclic (C2H5, i-C3H7, sec-C4H9) or cyclic (c-C3H5, c-C5H9, c-C6H11).
The different ligands participate in a remarkable range of interactions with the metal centre, including - and -C-H agostics, and, in the case of c-C3H5, a highly unusual -C-C agostic bond. Calculations performed using the hybrid Quantum Mechanics Molecular Mechanics (QMMM) technique reveal that the delicate balance between these agostic isomers (which are often observed in dynamic equilibrium) is caused by a subtle interplay of steric and electronic factors.For further information contact: Jeremy Ireland (Jeremy.Ireland@warwick.ac.uk)