Metal Cluster Topology. 5. Infinite Delocalization in One and Two Dimensions: Lanthanide and Early Transition Metal Halide Clusters Built from Fused Octahedra.
Abstract
It is shown how graph theory derived models for metal cluster bonding can be extended to infinite one-dimensional chains and infinite two-dimensional sheets of fused metal octahedra using lanthanide and early transition metal halide clusters as examples. Discrete octahedral metal clusters have the following skeletal bonding topologies distinguished by their electron counts: 1) Twelve edge-localized two-center bonds as in the Mo6(Mu3-X)8L6(4+) clusters; 2)Eight face-localized three-center bonds as in the Nb6(Mu2-X12)L6(2+) clusters; 3)Globally delocalized bonding with six two-center core bond as in the octahedral boranes, carboranes, and metal carbonyl clusters (e.g., Rh6(CO)16) and the zirconium octahedron clusters with light interstitial atoms such as Zr6CL12Be, Zr6CL13Be(-), Zr6CL16Be(4-), Zr6CL13B, Zr6CL14B(-), Zr6CL15B(2-), Zr6CL14C, and Zr6Cl15N. The infinite one-dimensional chains of fused octahedra in Gd2CL3 as well as the infinite two-dimensional sheets of fused octahedra in the zirconium monohalides have electron and orbital counts corresponding to six-center core bonds in each octahedral cavity and multicenter bonds in the two tetrahedral cavities for each octahedral cavity. A similar bonding model for bulk metals leads to the prediction of maximum heats of atomization for the group 6 metals.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 13, 1986
- Accession Number
- ADA174201
Entities
People
- R. B. King
Organizations
- University of Georgia