EMPTY OCTAHEDRAL HEXAZIRCONIUM CLUSTERS WITH ONLY 10 ELECTRONS, [ZR6X14(PR3)4]

No interstitial atom is found in the Zr6 octahedron of the [Zr6X14(PR3)4] cluster 1 (X = Cl, Br; R = Me. Et, Pr) according to the results to NMR studies. SCF-X-alpha-SW-MO calculations, and X-rav crystallography (structure here for X = Cl, R = Me, phosphane ligands omitted). In all the clusters examined, four terminal PR3 ligands are bound to the Zr atoms in the equatorial plane, two halogen atoms cap the axial Zr atoms, and all the edges of the octahedron are bridged by halogen atoms. Cluster 1 is synthesized by the reduction of ZrX4 with (nC4H9)3SnH followed by addition of phosphane.