STRUCTURES, DYNAMIC BEHAVIOR IN SOLUTION AND CROSS-COUPLING REACTIONSOF THE ALPHA-PALLADIATED (ETA(6)-ALKYLARENE)TRICARBONYLCHROMIUM COMPLEXES CONTAINING A PALLADIUM-CHROMIUM BOND

Structures of the complexes (eta(3)-C3H5)Pd(mu-eta(6:1)-CH2Ph)Cr(CO)(3 ) and (eta(3)-C3H5)Pd[mu-eta(6:1)-CH(Ph)Ph]Cr(CO)(3) in solution were evaluated by NMR (H-1 and C-13) and IR spectroscopy. The dynamic behav iour of the complexes was investigated. Quick rotation (on the NMR tim e scale) of the tricarbonylchromium groups around the axis passing thr ough the centre of the eta(6)-coordinated phenyl ring and the chromium atom takes place at room temperature and becomes slow on cooling. The eta(3)-allylic ligand was proved to undergo no dynamic changes in sol ution. Unlike the solid state, the semi-bridging carbonyl groups betwe en chromium and palladium atoms are absent or very weak in solution. C ross-coupling reactions of the complexes with organohalides are descri bed. (C) 1998 Elsevier Science S.A. All rights reserved.