Synthesis ligand exchange

There are two principal synthetic routes to dicarboxylate complexes. One of these uses an aqueous solution of the alkali metal dicarboxylate and the corresponding metal halide,93 while the other depends upon the dicarboxylic acid reduction of higher oxidation state metals. This reductive property of oxalic acid results in its ready dissolution of iron oxides and hence a cleaning utility in nuclear power plants.94 Mention must also be made of the successful ligand exchange synthesis of molybdenum dicarboxylates, Mo(dicarboxylate)2 H2 O, from the corresponding acetate complex. Unfortunately the polymeric, amorphous and insoluble nature of these complexes has restricted the study of these systems, which may well provide examples of multiple M—M bonding in dicarboxylate coordination chemistry.95... 

Deacon, GB. and Forsyth, C.M. (2003) A half-sandwich perfluoroorganoytterbium(ll) complex from a simple redox transmetalation/ligand exchange synthesis. Organometallics, 22, 1349. 

Woehrle GH, Hutchison JE. Thiol-functionalized undecagold clusters by ligand exchange Synthesis, mechanism, and properties. Inorg Chem 2005 44 6149-6158. 

Early examples of enantioselective extractions are the resolution of a-aminoalco-hol salts, such as norephedrine, with lipophilic anions (hexafluorophosphate ion) [184-186] by partition between aqueous and lipophilic phases containing esters of tartaric acid [184-188]. Alkyl derivatives of proline and hydroxyproline with cupric ions showed chiral discrimination abilities for the resolution of neutral amino acid enantiomers in n-butanol/water systems [121, 178, 189-192]. On the other hand, chiral crown ethers are classical selectors utilized for enantioseparations, due to their interesting recognition abilities [171, 178]. However, the large number of steps often required for their synthesis [182] and, consequently, their cost as well as their limited loadability makes them not very suitable for preparative purposes. Examples of ligand-exchange [193] or anion-exchange selectors [183] able to discriminate amino acid derivatives have also been described. 

R R M were prepared by reduction of the dibromides R R MBr2 with lithium naphthalenide (method A), by thermolysis of a disilene (method B), and the ligand exchange of divalent group 14 element species (method C). In all cases except for the synthesis of Tip2PbS4, exclusively tetrasulfides R R MS4... 

Here, we have used this method for the synthesis of Au SG clusters. Undecagold clusters (Aun ) stabilized by triphenyl phosphine (TFF) were prepared according to the literature [6]. An aqueous solution of GSH was placed on top of a chloroform solution of Au TFF. The Au SG clusters were transferred to the aqueous phase as a result of ligand exchange reactions [19]. 

The synthesis of asymmetrically substituted stannylenes is most efficiently achieved by ligand exchange reactions between two stannylenes, SnXj and SnY2 (see Chapter 4). For example, the stannylenes [(Me3Si)2NJClSn and (C5H5)ClSn can be synthesized according to Eqs. (36) and (37) 86,93 94). 

We successfully reproduced the synthesis of the Mo(IV) oxo-chloro complex 1 from [MoCl4(thf)2] and PMe3 in aqueous THF as well as the ligand exchange reaction with dmpe. Reaction of 1 with the tetradentate ligand prP4, however, did not lead to an isolable product. 

Chemisorption Adsorbate Orientation Competitive Chemisorption Adsorbate Exchange Adsorbate Reactivity Electrocatalvsis Synthesis Mode of Coordination Ligand Substitution Ligand Exchange Ligand Reactivity Homoqeneous Catalysis... 

SCHEME 3.75 Schematic reaction to synthesis/ac-Ir(ppy)3 via bidentate acac ligand exchange. 

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