Bond involving d orbitals

From the observed values of interatomic distances in complex ions such as [SnCh]—, [PbBr0], and [SeBr ]— and from crystals such as TiS2 with the cadmium iodide structure the octahedral radii given in Table 7-17 have been obtained. These correspond not to cPsp bonds, involving d orbitals of the shell within the valence shell, but to sp d2 orbitals, use being made of the unstable d orbitals of the valence shell itself. 

From the limited data available, we may assume that the two S-S distances are normally equal for isolated molecules of symmetrically substituted 1,6,6aS rv-trithi apentalenes, but these S-S bonds involving d orbitals seem very sensitive to extramolecular influences in the crystal lattice111 and to intramolecular perturbations, such as unsymmetrical substitution. Unequal spacing of the sulfur atoms may perhaps also result from steric interactions between symmetrically placed substituents.114... 

Jaffe, H. H. Studies in Molecular Orbital Theory of Valence. III. Multiple Bonds Involving d-Orbitals. J. physic. Chem. 58, 185—190 (1954). 

Directional natiire oj bonds involving d orbitals— The atoms of the transition elements may take part in both c and n bonds in the formation of a compound. The number of a bonds formed by the central atom cannot exceed the number of surrounding atoms or groups since between any pair of atoms, only one a bond is permissible, but the number of less than the number of neighbours, since bonds other than the covalent are possible, e.g, bonds due to ion-dipole and dispersion forces. 

Craig DP, Macoll A, Nyholm RS, Orgel LE (1954) Chemical bonds involving d orbitals I. J Chem Soc 332-353... 

Jaffe HH (1954) Studies in molecular orbital theory of valence multiple bonds involving d-orbitals. J Phys Chem 58 185-190... 

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