Spectrochemical series of ligands

To our knowledge, the only low-spin complex, for which specdal data are reported, is the Mn(CN)6 anion [42]. A rough estimate of the ligand field parameters for the latter polyhedron yields, if one utilises the factorisations according to the nephelauxetic and spectrochemical series of ligands [6] in relation to the known A and B parameters for fluoride (Table 4) ... 

The ligand field spectra of orthoaxial chromium(iii) complexes have been studied by calculations utilizing the angular overlap model. A two-dimensional spectrochemical series of ligands has been established for Cr ". Certain observations do point towards a chemical significance for such parameters. ... 

This series is not quite as regular as the spectrochemical series of ligands, but some general regularities are seen ... 

We see, then, that the magnetic properties of coordination compounds are consistent with CFT. Furthermore, these properties can be used to substantiate the spectrochemical series of ligands. 

Backward Ni(OC) is clearly inferior to Ni(CO), because Kq is inferior to c as a donor, and the n co acceptor is polarized away from the contact point with Ni, thus diminishing its advantage as a 7r -acceptor relative, to H2O or other Uq donors. Thus, from (8.20) and (8.21) we can anticipate the qualitative order of ligand coordinative strength, consistent with the well-known empirical spectrochemical series of ligands. 

The cobalt(II) complexes with R-dtp and related ligands are readily oxidized by air and other oxidizing agents to yield the corresponding cobalt III) tm-chelates. Electronic spectra and Co NMR spectra data 334,33s) hayg shown that the spectrochemical series of sulfur ligands is ... 

Not only does the central atom itself influence the activity of the chelate concerned but also its immediate neighbors. The activity of the symmetrical plane square Co and Fe complexes, like the ligand field strength, decreases according to the spectrochemical series of the donor atoms concerned in the order... 

Figure 1-7. The spectrochemical series arranges ligands in the order of their effect upon the magnitude of A. Iodide is a weak field ligand and gives small ligand field splittings, whereas carbon monoxide gives a strong field and a large A.

Fig. 20-45. A qualitative two-dimensional spectrochemical series of some ligands, as...

To summarize the present results, Co (II) ions can be introduced into the Type A molecular sieves into the S-II type positions, where they are stable and resist both oxidation and reduction. These ions bind nitrous oxide, cyclopropane, water, and ammonia as additional ligands, their spectra being simultaneously changed in a defined fashion. The spectrochemical series of these ligands is, in the order of increasing ligand strength,... 

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