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Metal Chain (metal + chain)

Distribution by Scientific Domains
Chemistry100%

Selected Abstracts

Stabilization of Long Cationic EMACs by Reduction or Loss of One Metal Ion

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 27 2008
Rayyat H. Ismayilov
Abstract The new pyrimidyl- and naphthyridyl-modulated pentapyridyltetramine ligand (H3N9 -2pm) and its linear nona- and octanickel chain complexes were successfully synthesized. The nonanickel complex [Ni9(,9 -N9 -2pm)4Cl2](PF6)2 (1) contains two fully delocalized, mixed-valence [Ni2(napy)4]3+ units. Magnetic measurements performed on the defective octanuclear complex [Ni8(,8 -N9 -2pm)4Cl2](PF6)2 (2) demonstrate that the metal chain provides a pathway of magnetic superexchange coupling over the extended metal atom chain (EMAC). (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source]

Facile Synthesis of Nitrogen Tetradentate Ligands and Their Applications in CuI -Catalyzed N-Arylation and Azide,Alkyne Cycloaddition

CHEMISTRY - A EUROPEAN JOURNAL, Issue 40 2009
Fuwei Li Dr.
Abstract Five new tetradentate ligands [NNNN] with benzimidazolyl-imine or amine nitrogen donors have been synthesized in good yields under mild conditions from easily available substrates. trans - N,N,-bis(1-Ethyl-2-benzimidazolylmethylene)cyclohexane-1,2-diimine is the best accelerating ligand in this series that supports the CuI -catalyzed Ullmann N-arylation and the direct three-component azide,alkyne cycloaddition reaction to give the corresponding substituted imidazole, pyrazole, and triazole in high yields. Single-crystal X-ray diffraction analysis of its complex with CuI reveals a novel one-dimensional coordination polymer of the metal chain bridged alternately by the [NNNN] ligand and diiodides. [source]

Enantioseparation of extended metal atom chain complexes: Unique compounds of extraordinarily high specific rotation

CHIRALITY, Issue 3 2007
Molly M. Warnke
Abstract Extended metal atom chains (EMACs) contain a linear metal chain wrapped by various ligands. Most complexes are of the form M3(dpa)4X2, where M = metal, dpa = 2,2,-dipyridylamide, and X = various anions. The ligands form helical coils about the metal chain, which results in chiral EMAC complexes. The EMACs containing the metals Co and Cu were partially separated in polar organic mode using a vancomycin-based chiral stationary phase. Under similar conditions, two EMACs with Ni metal and varying anions could be baseline separated. The polar organic mode was used because of the instability of the compounds in aqueous mobile phases. Also, these conditions are more conducive to preparative separations. Polarimetric measurements on the resolved enantiomers of Ni3(dpa)4Cl2 indicate that they have extraordinarily high specific rotations (on the order of 5000 deg cc/g dm). Chirality, 2007. © 2006 Wiley-Liss, Inc. [source]