Ligand-field strengths, determination

Ligand field strength may determine coordination geometry. For example, NiCll" occurs as a tetrahedral complex (small splitting—small At ), whereas... 

In the case of mixed ligands photoreactivity may be predicted empirically from considerations of the ligand field strength (Adamson s rule). For O/, complex, the axis having the weakest average held as determined by the position of its respective ligands in the spectroehemical series will... 

This correlation has been used in the work of Konig and Kremer212-213) who parameterized the experimental susceptibility data by a temperature dependent energy separation e(T) = E(5T2) - E( Ax) determined by the ligand field strength. 

State. When both iron environments contain only iron(II), the resulting salt is not colored (Prussian White). The oxidation state localization in PB has been studied extensively. Structures, electrochemical behavior (electrodes batteries), and uses in medicine (treatment of Cs and of thallium poisoning) of Prussian Blue are mentioned in a review of cyanide complexes. In cobalt-iron Prussian Blue analogues, NaxCo3,Fe(CN)6-zH20 electronic and spin states are controlled by temperature and the ligand field strength around the Co + ions, which in turn is determined by the Co Fe ratio. ... 

Would it be better to use octahedral Ni2+ complexes or octahedral Cr2+ complexes to determine whether a ligand is a high-field or low-field ligand by determining experimentally the number of unpaired electrons How else could the relative ligand field strengths be determined ... 

In order to increase the solubility of porphyrin and phthalocyanine complexes, several structural modifications have been made, a, jS, y, 6-Tetra-(4-pyridyl)-porphin complexes of copper(II), nickel(II), and zinc(II) have been synthesized (35) and their ultraviolet spectra determined in chloroform and in acid solution. By utilizing sulfonic acid groups to increase solubility, complexes of 4,4, 4",4" -tetrasulfophthalocyanine complexes of many metals were prepared (94j 95). This chelating agent was found to have a ligand field strength comparable to cyanide (94y 95). 

Steady state absorption allows determination of the ligand field strength acting on the Cr " ion. The absorption due to T2 spin-allowed transition peaks around 650 to... 

Pr(Tp)3] has been reported, structurally characterized, and its absorption and luminescence spectra discussed. The global field experienced by Pr3+ and the individual ligand field strength due to the Tp ligand, as also nephelauxetic parameters were determined.605... 

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