Ligands oxidation

Synthetic and structural chemistry of heme derivatives with nitrogen oxide ligands 99ACR350. 

It is very common for inorganic chemists to neglect or ignore the presence of solvent molecules coordinated to a metal centre. In some cases, this is just carelessness, or laziness, as in the description of an aqueous solution of cobalt(ii) nitrate as containing Co ions. Except in very concentrated solutions, the actual solution species is [Co(H20)6] . In other cases, it is not always certain exactly what ligands remain coordinated to the metal ion in solution, or how many solvent molecules become coordinated. Solutions of iron(iii) chloride in water contain a mixture of complex ions containing a variety of chloride, water, hydroxide and oxide ligands. 

Fig. 6.10 Examples of the directional effect of oxide ligand arrangement on the location of hard cations and orientation of M-O linkages.

The number of valence electrons in niobium oxychloride clusters decreases as the number of oxide hgands increases (Table 6.4). The compound Cs2LuNbi Cli70 has the VEC of 16 as found in most chloride clusters, suggesting that the presence of one oxide ligand per cluster does not tip the balance between the Nb-Nb bonding and Nb-L anti-bonding contributions to the a2u state. The VEC of most clusters... 

This chromium complex, and the molybdenum and tungsten analogues with two N-oxide ligands, were all explosive [1]. The chromium complex has exploded during desiccation [2],... 

The analogous complex of molybdenum, and that of chromium with a single N-oxide ligand, were also explosive. 

Fluorous ligands introduce an ease of purification in that the tagged phosphine ligand, the palladium catalyst complexed ligand, and the oxidized ligand can be completely removed by direct fluorous solid-phase separation (F-SPE) prior to product isolation. Similarly, an example of a fluorous palladium-catalyzed microwave-induced synthesis of aryl sulfides has been reported, whereby the product purification was aided by fluorous solid-phase extraction [91]. 

R.R. Schrock We believe so, but the t-but oxide ligand seems to be a unique alkoxide. We have prepared tungstenacyclobutadiene complexes containing other alkoxide ligands which are stable toward decomposition to an alkylidyne complex. 

Use of D2 yielded CD4, and methane was formed from reaction of the complex with just H2. The water produced in the reaction hydrolyzes the titanium complex to an inactive cluster Cp6Ti608 containing bridging oxide ligands. 

An interesting approach to rhenium bioconjugate formation that has been developed but apparently has yet to be fully evaluated from the standpoint of applicability and stability is the use of chelating and nonchelating phosphine imine and phosphine oxide ligands [110]. For... 

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