DI-MU-CHLORO-BIS[DICARBONYLPALLADIUM(I)] MOLECULAR-STRUCTURE CHARACTERIZATION BY HARTREE-FOCK AND LOCAL SPIN-DENSITY METHODS

Molecular electronic structure calculations of the experimental hinge and hypothetical planar molecular conformations of the title compound have been carried out. To obtain a reasonable description we have used restricted and unrestricted Hartree-Fock (HF); singlets and triplets configuration interaction and local spin density (LSD) followed by non local corrections. All our results for the experimental hinge conform ation confirm a B-3 ground state. For the planar conformation all meth ods, except LSD, predict B-3 as the ground state. For the hinge and pl anar conformations a negative large Mulliken bond order is shown for t he Pd-Pd bond. This Pd-Pd interaction is larger for the B-3 State than for the (1)A state. A dissociation of the molecule in hinge conformat ion is obtained when a geometry optimization of the B-3 and (1)A state s is carried out. This dissociation is obtained with both the HF and t he LSD methods. This last result is in agreement with the experimental observation of extremely low stability of the compound, together with the low yield of the synthesis. (C) 1997 Elsevier Science B.V.