Other Configurations Involving d Orbitals

Both quadripositive and quinquepositive molybdenum and tungsten form complexes with eight oyanide groups. In these complexes a molybdenum atom has available five Ad orbitals, one 5s orbital, and 

214 (1943). Racah finds that the best eight equivalent dap orbitals have strength 2.9886 they are direoted toward the corners of a tetragonal antiprism, with angle 60°54 with the tetragonal axis. 

The substances K8Re(CN)8 and K8Re(CN)8, recently reported,74 probably contain Re(V) and Re(VI) with ligancy 8 and the same configuration as the molybdenum octacyanide complexes. 

The configuration of the eight oxygen atoms bonded to the thorium atom in thorium(IV) acetylacetonate, Th(C H70 )4, has been found76 to be that of the tetragonal antiprism (Fig. 5-16). Each bidentate ligand connects adjacent corners of one of the squares of the polyhedron. 

The same configuration has been reported also for molybdenum pentachloride,7 MoCl , antimony pentachloride,80 SbCli, and the tri-methylstibine dihalides,81 (CH ) 3bX. Molybdenum pentachloride 

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