Octanuclear Bis(triple-helical) Metal(II) Complexes

Abstract

pounds 3Ϫ5 which range from colourless to orange in appearance. The compositions of these complexes were determined by FAB mass spectrometry (FAB ϭ fast-atom bombardment). The FAB-MS spectrum of complex [Zn 8 O 2 L 2B 6 ] (3) exhibits the correct molecular peak and isotopic pattern at m/z 2519 (Figure 1). According to their FAB-MS data, the corresponding cadmium (4) and manganese (5) complexes have the same composition.

Complexes of a novel multinucleating poly-β-diketonate ligand

“…A few complexes of poly-b-diketone ligands have been published previously by other groups. [12][13][14] We recently reported the synthesis of the pentadentate ligand 1,3-bis-(3-oxo-3-phenylpropionyl)-2-hydroxy-5-methylbenzene (H 3 L, see scheme I). 11 The structure of this molecule displays two b-diketone units and one phenol group, disposing five oxygen donor atoms in a linear array, aimed at inducing the aggregation of transition metals in the form of short, molecular chains.…”

The new multi-directional polydentate ligand 2,4,6-(di-pyridin-2-yl-amino)-[1,3,5]triazine (dpyatriz) can discriminate between Zn(II) and Co(II) nitrate

“…Ligand field spectra of the solid compounds were recorded on a PerkinÁ/Elmer Lambda 900 UV Á/VisÁ/ NIR spectrometer in the diffuse reflectance mode with MgO as reference. 2,4,6-(Di-pyridin-2-yl-amino)- [1,3,5]triazine (dpyatriz) was prepared as previously described [15]. …”

“…Results and discussion 3.1. Ligand synthesis, structure and general observations 2,4,6-(Di-pyridin-2-yl-amino)- [1,3,5]triazine (dpyatriz, (1), Fig. 1) was synthesized from 2,4,6-trichloro-1,3,5-triazine and 2,2?-pyridylamine according to a published procedure [15].…”

“…In the present study, it was investigated whether the large, potentially nonadentate polypyridyl ligand 2,4,6-(di-pyridin-2-yl-amino)- [1,3,5]triazine (dpyatriz) [14], could discriminate between two rather similar metal ions such as Zn(II) and Co(II). Therefore, representative nitrate complexes were prepared and structurally characterized; for comparison also the structure of the free ligand is reported.…”

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The new multi-directional polydentate ligand 2,4,6-(di-pyridin-2-yl-amino)- [1,3,5] , where each ligand binds to three Zn ions. Two of the Zn ions are five coordinated in a ZnO 3 N 2 chromophore (the trigonal bipyramidal geometry is completed by two monodentate nitrato ligands).

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