Configurational in octahedral complexes

It is not clear why this luminescence does not appear in solution. Complexes of d metals of the second and third transition row do not seem to show an LF emission. Such metal ions exist only in low-spin configurations. In octahedral complexes they then possess an electron hole in their dn subshell. It follows that such compounds are often characterized by low-energy LMCT transitions [8]. Accordingly, LF emissions are not likely to occur. 

For which d electron configurations in octahedral complexes is it possible to distinguish between high-spin and low-spin arrangements ... 

In high-spin species (to which the theorem is not restricted), perusal of the appropriate configurations for octahedral complexes across the transition period (see Fig. 5-1) shows that d" and configurations are candidates for the Jahn-Teller... 

Term labels appropriate for d3 and d6 configurations in octahedral ligand fields will be used in this review to designate the ligand field or d-d excited states of cobalt(III) and chromium(III) complexes. This... 

In a complex that possesses a center of symmetry, all states arising from a dn configuration have the g character inherent in the d orbitals. Since the dipole moment vectors belong to odd representations, all of the integrals such as / y/gXi//g dr are identically zero because the direct product of two g functions can never span any u representations. On this basis alone, we would predict that transitions between the various states arising from dn configurations in octahedral environments would have zero absorption intensity. In fact, these transitions do take place but the absorption bands are only —lO"3 times the intensity expected for symmetry allowed electronic transitions. Thus the prediction we have made is substantially correct, but at the same time there is obviously some intensity giving mechanism that has been overlooked. 

In octahedral complexes, the choice between high-spin and low-spin electron configurations arises only for dA-d7 complexes. Explain. 

Rigorous chemical correlation of optical configuration of octahedral complexes must therefore rest at present on reactions where no bond to the metal is broken. Unlike organic chemistry few such cases have been reported. Fortunately even rather trivial cases are of value for example, coordinated water and coordinated hydroxide ion have different ligand field strengths, and thus the changes of O. R. D. and C. D. in reactions such as... 

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