文摘
The Ni6C(CO)9(AuPPh3)4 bimetallic carbide carbonyl cluster was obtained from the reaction of [Ni9C(CO)17]2鈥?/sup> with Au(PPh3)Cl. It contains a rare carbon-centered (distorted) Ni6C octahedral core decorated by four Au(PPh3) fragments. These are 渭3-bonded to four contiguous Ni3-triangular faces and display weak intramolecular Au路路路Au d10鈥揹10 interactions. The cluster has been characterized in the solid state on two different solvato crystals, i.e., Ni6C(CO)9(AuPPh3)4路THF and Ni6C(CO)9(AuPPh3)4路THF路0.5C6H14. The two solvates show some interesting differences concerning the weak Au路路路Au contacts. Density functional theory calculations have demonstrated that the presence of the two isomers is related to solid-state packing effects and not to the existence of two double minima in the potential energy surface. This, in turn, confirms that Au路路路Au d10鈥揹10 interactions are rather soft and thus influenced also by weak van der Waals forces because of the interaction of the cluster with the cocrystallized solvent molecules.