Organolanthanide chemistry

The growth of organoactinide chemistry, like that of organolanthanide chemistry, is comparatively... 

A review article entitled "Bulky amido ligands in rare-earth chemistry Syntheses, structures, and catalysis" has been published by Roesky. Benzamidinate ligands are briefly mentioned in this contexD The use of bulky benzamidinate ligands in organolanthanide chemistry was also briefly mentioned in a review article by Okuda et al. devoted to "Cationic alkyl complexes of the rare-earth metals S mthesis, structure, and reactivity." Particularly mentioned in this article are reactions of neutral bis(alkyl) lanthanide benzamidinates with [NMe2HPh][BPh4] which result in the formation of thermally robust ion pairs (Scheme 55). ... 

Anwander R (1999) Principles in Organolanthanide Chemistry. 2 1-62 Arends IWCE, Kodama T, Sheldon RA (2004) Oxidations Using Ruthenium Catalysts. 11 277-320... 

Analysis of possible structures and reaction pathways in reactions 1-4 led to various model structures for these complexes (9t25). Some of these involved C-H activation of the substituents attached to the unsaturated carbon atoms. To test the validity of these models, two additional types of metal vapor reactions were examined. In one case, reactions with simpler unsubstituted hydrocarbons were examined. In another case, substrates ideally set up for oxidative addition of C-H to the metal center were examined. As described in the following paragraphs, both of these approaches expanded the horizons of organolanthanide chemistry. 

Tris(i/5-cyclopentadienyl)lanthanides were the first authentic organolanth-anides to be prepared1 and bis(t/5-cyclopentadienyl)lanthanide(II) compounds have played a germinal part in the development of lower oxidation state organolanthanide chemistry.2 These cyclopentadienyls are sources of coordination compounds of structural interest and are reagents for the synthesis of other organolanthanides, for example, bis- and mono(t)5-cyclopentadienyl)lanthanide(III) derivatives.2... 

Table 1. Review articles covering predominantly Ln-C based organolanthanide chemistry"...

Table 2. Review articles covering Ln-N and Ln-O based organolanthanide chemistry...

In this article, the authors want to work out the relationship between the intrinsic properties of a lanthanide element and an organic ligand, which frequently leads to an intriguing synergism in organolanthanide chemistry. The consideration of specific properties of the lanthanide cations as well as thermo-... 

The central point in this consideration is the Ln-OH moiety, the preferred formation of which is considered to be a dilemma in organolanthanide chemistry. Organolanthanide compounds containing Ln-X a-bonds such as alkyls, amides and alkoxides readily hydrolyze when exposed to moist air, with the formation of the hydroxides. Lanthanide complexes with Ln-C linkages are considered to be oversensitive compounds [89]. Even ligands with lower pKa values than water, as exemplified by substituted phenol ligands, tend to hydrolyze in organic solvents because the insoluble hydroxides formed act as... 

Ln-Halides. The complexation/solvation criteria is just one reason why lanthanide halides are the most common precursors in organolanthanide chemistry. In this evaluation, lanthanide iodides are often preferred to bromides and chlorides, however the former are more difficult to synthesize and are much more expensive [96f. Waterfree, solid Ln-halides are ionic substances with high melting points which immediately absorb water when exposed to air, forming hydrates (I > Br > Cl ). Therefore, they have to be handled under an inert gas atmosphere. The main use of the halides is for the production of pure metals [96]. Some methods of preparing Ln(III)-chlorides are summarized in Scheme IV [96],... 

No doubt, donor-functionalized ligands are becoming more and more popular in organolanthanide chemistry. The availability of donor-functionalities may be helpful not only in the fine-tuning of the above-mentioned spectator ligand environment. Intramolecular ring formation via dative bonds [183] can produce monomeric, homoleptic systems which show remarkable properties... 

Scheme VIII gives a representative selection of donor-functionalized ligands employed in the main classes of organolanthanide chemistry. Ln-O- and Ln-N-based systems are exhaustively treated in the following articles of this book [185-188]. Donor-functionalization is also applied as a route to thermally stable...

Scheme VIII. Donor-functionalized ligands applied in organolanthanide chemistry...

The efficiency of functionalized cyclopentadienyl complexes is meanwhile well established [78,191-202]. Because cyclopentadienyl ligands still dominate the field of organolanthanide chemistry, a selection of the functionalized ligands utilized is depicted in Fig. 11. In the field of aryl complexes, which represented the first well-characterized homoleptic derivatives [203], multiple functionalization has already been started [204]. 

The text of this chapter on Features of Organolanthanide Chemistry has been geared to the precursor chemistry of potential applications in the fields of catalysis and material sciences, which are certainly two of the most-discussed topics in current publications. However, organolanthanide chemistry has also penetrated other important areas for example, in a text on macrocyclic derivatives the topic probes in life is to be found [92]. 

Organolanthanide chemistry has mainly been developed using the cyclopen-tadienyl CsHsfCp) group and its substituted derivatives, such as CsMes (Cp ), largely because their size allows some steric protection of the large metal center. 

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