Ligand open-chain quadridentate

Studies of the mechanism of stereoselective synthesis of quadridentate open-chain ligands by copper(II)-directed condensation of amino acids have included molecular mechanics analysis of possible intermediates. From racemic aniline, the only condensation product detected for [Cu(2,5,8-trimethyl-5-nitro-3,7-diazanonanedioate)] was the (2R, 85) isomer. A model was proposed to explain this selectivity. With a racemic amino acid, one side is blocked, as shown in Figure 11. Molecular mechanics calculations were performed with... 

By reaction of benzil monohydrazone, 2,3-butanedione or 3,3 -dimethyl-l,2-butanedione monohydrazone with acetone in the presence of nickel(n), complexes [Ni(L122)]-(Ni(L124)] containing quadridentate open-chain ligands were obtained (Eq. 2.69). They consist of two residues of a monohydrazone a-dicarbonyl com-... 

Co(LLLL)(L)X] + and [Co(LLLLL)X] + Complexes. Included in this section are studies in which the non-leaving group is an open-chain or cyclic quadridentate (LLLL) or quinquedentate (LLLLL) ligand. Excluded are the complexes of edta and related ligands discussed earlier and the dioximato-complexes covered in the next section. 

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