Ligand substitution reactions lanthanides

The photochemistry of lanthanide ions is limited to photoredox reactions. Photo substitution has not been studied because of the lability of metal ions, and since ligand substitution reactions are rapid even under thermal conditions. 

Lanthanides, 9, 361-380 Lead compounds, 6, 247-250 7, 245-256 Ligand substitution reactions in metal tt-complexes, 10, 347-409 Lithium alkyls, 6, 202 8, 168-170... 

The rate constants for the reaction of murexide with lanthanides obtained by Geier [21] are of similar magnitude as those of oxalate complexes. The forward rate is insensitive to the nature of the entering ligand which provides support for the operation of the four-step mechanism proposed by Eigen [18]. The substitution reactions of lanthanides appear to be governed by the four-step mechanism. The rate determining step in this mechanism is the... 

To create a ligand scale, corresponding to the second substitution reaction of Section 2, we consider the differences between stability constant logarithms for soft and hard metal ions for several ligands. Hg + stands as the preeminent soft metal ion. Sc + is the hardest metal ion in all three of the above scales, but results are limited. More hgands may be included if results for the smaller and heavier lanthanides are considered for the hard metal ion. For 16 ligands, the difference between the stability constant logarithms for Hg + minus a lanthanide in parentheses is as follows. 

The kinetics have been reported for the formation of several edta-5-sulfosalicylate ternary complexes of lanthanide ions, and ligand substitution in trimalonatovanadium(III) with edta and nta . Reports have also appeared on the formation of ternary complexes involving Fe(III), pyridoxamine, and pyridoxal and the formation of bis- and tris(acetohy-droxamato)Fe(III) and activation volume evidence has been provided for a dissociative mechanism in the reaction of thiocyanate with diaqua[mcso-tetrakis(Af-methyl-4-pyridyl)porphinato] cobalt(III). 

It should be noted that the basic reactions used to prepare phthalocyanine derivatives today are fundamentally those developed by Linstead and coworkers in the 1930s [52-54]. Due to the large number of substituted phthalocyanines described in the literature, space limitations mean that a detailed review of synthetic aspects cannot be provided here. The following discussion is concerned with the synthesis of lanthanide phthalocyanines via (i) template tetramerization of phthalonitrile with lanthanide salts, (ii) direct metalation of the metal-free ligands by the salts or (iii) metal exchange of a labile metal ion or ions for a lanthanide. 

Within solution inorganic chemistry, there would be no apparent reason to obtain NMR spectra at high pressures in structural characterization studies. It prevails that most applications of hp NMR spectroscopy relate to solvent exchange reactions on solvated metal ions their mechanisms often have direct bearing upon the kinetics and mechanisms of substitution of one or more solvent molecules from a metal center by other ligands. The first part of the results section provides ample illustration of the value of high-pressure measurements on transition metal and lanthanide ions, fully... 

Figure 5.3 Synthetic conditions for the mixed-ligand Pc complexes, containing one Pc ligand. Route 1 interaction of o-dicyanobenzene(s) and their analogues with lanthanide salts. Route 2 metallation reaction of the macrocyclic ligand or its dianione by lanthanide compounds. Route 3 reactions of axial substitution in the environment of the central atom in lanthanide complexes ([96] and references cited therein). (From Ref. 96, with permission.)...

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