Coordination complexes synthesis

Coordination Complexes. The coordination and organometaHic chemistry of thorium is dominated by the extremely stable tetravalent ion. Except in a few cases where large and stericaHy demanding ligands are used, lower thorium oxidation states are generally unstable. An example is the isolation of a molecular Th(III) complex [107040-62-0] Th[Tj-C H2(Si(CH2)3)2]3 (25). Reports (26) on the synthesis of soluble Th(II) complexes, such as... 

The only reports of directed synthesis of coordination complexes in ionic liquids are from oxo-exchange chemistry. Exposure of chloroaluminate ionic liquids to water results in the formation of a variety of aluminium oxo- and hydroxo-contain-ing species [4]. Dissolution of metals more oxophilic than aluminium will generate metal oxohalide species. FFussey et al. have used phosgene (COCI2) to deoxochlori-nate [NbOa5] - (Scheme 6.1-1) [5]. 

The most effective catalysts for enantioselective amino acid synthesis are coordination complexes of rhodium(I) with 1,5-cyclooctadiene (COD) and a chiral diphosphine such as (JR,jR)-l,2-bis(o-anisylphenylphosphino)ethane, the so-called DiPAMP ligand. The complex owes its chirality to the presence of the trisubstituted phosphorus atoms (Section 9.12). 

This index contains over 25 000 entries to the 6562 text pages of Volumes 1-6. The index covers general types of coordination complex, specific coordination complexes, general and specific organic compounds where their synthesis or use involves coordination complexes, types of reaction (insertion, oxidative addition, etc.), spectroscopic techniques (NMR, IR, etc.), and other topics involving coordination complexes, such as medicinal and industrial applications. 

Other iron-imido complexes have also been reported. Holland and coworkers reported the synthesis of the imidoiron(III) complex [L FeNAd] [40, 41]. This imidoiron(III) complex has not been isolated and was found to convert to a purple high-spin iron(III) complex. It has an S = 3/2 ground state from EPR measurement. Based on the results of QM/MM computations, [L EeNAd] is a three-coordinated complex with an Fe-N distance of 1.68 A and has a nearly linear Fe=N-C unit with Fe-N-C angle of 174.1°. Chirik and coworkers made use of liable ligands to prepare iron-imido complexes by treatment of C PDI)-Fe(N2)2 ( PDI = (2,6- Pr2CgH3N = CMe)2C5H3N) with a series of aryl azides [47]. 

A template synthesis employing Ni(OAc)2, 2,5-dihydroxy-2,5-dimethyl-1,4-dithiane, and 3,3 -iminobis(propylamine) gave the water-soluble five-coordinate complex [Ni(495)], the crystal structure of which shows trigonal bipyramidal coordination of Ni11 with the central amine and terminal thiolates in plane and the two imino nitrogens in axial positions. Solvatochromism of the complex is interpreted in terms of S" H bonding, which may be of relevance to the catalytic cycle in hydrogenases.1341... 

A tridentate SNO ligand coordinates with a bipyridine to give ((2,2 -bipyridine)[2-(2-mercapto-phenyl)iminophenoxy])zinc. The monomeric complex has a distorted trigonal bipyramidal geometry with a phenolate and a thiolate coordinated. The synthesis was carried out electrochemically from anodic zinc in the presence of a disulfide-linked ligand precursor.867... 

There is no other vitamin which exemplifies the interdependence between the human race and microorganisms better than Vitamin B12. Mankind still relies for its very existence upon the capability of a few species of bacteria to synthesize this fascinating coordination complex. A concerted effort is being made in a number of laboratories to determine procedures for the chemical synthesis of this vitamin. However, even the most talented synthetic chemists would have to admit that the organic chemist s lament is applicable to Vitamin B12 ... 

In this review we shall not deal with the synthesis of this coordination complex, but we shall deal with the chemical properties of B 12-coenzymes with special emphasis on how these properties relate to Bi2-enzyme mechanisms. Also, we shall show how B -catalyzed methyl-transfer reactions have special significance in the biosynthesis of methylated heavy metals in the aqueous environment, and how the synthesis of these organometallic compounds has special relevance to problems concerned with continuing global environmental health hazards. 

Aryl derivatives of the heavier group 6 derivatives can also serve for the synthesis of arylmercury compounds.52 For instance, treatment of the diaryltellurium complex 30 with HgCl2 leads to the formation of a coordination complex which undergoes a slow dismutation reaction to afford the arylmercury chloride derivative 31 and the corresponding tellurium species (Scheme 3).53... 

Prior to their work with the Strecker reaction the Jacobsen group reported a combinatorial approach to the discovery of coordination complexes (29). A modular approach was taken in the synthesis of libraries of potential ligands for transition metals. Four variable components were used. Two amino acids were placed at positions 1 and 2, with a turn element connecting these groups (Scheme 9). The... 

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