کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1336091 | 979567 | 2011 | 8 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Syntheses, molecular and supramolecular structures, electrochemistry and magnetic properties of two macrocyclic dinickel(II) complexes Syntheses, molecular and supramolecular structures, electrochemistry and magnetic properties of two macrocyclic dinickel(II) complexes](/preview/png/1336091.png)
The work in this paper reports syntheses, molecular and supramolecular structures, electrochemistry and magnetic properties of two diphenoxo-bridged dinickel(II) compounds [NiII2L(N3)2(H2O)2]·CH3CN (1) and [NiII2L(N3)2(H2O)] (2), where H2L is the tetraimino diphenolate macrocyclic ligand, obtained on [2 + 2] condensation of 4-methyl-2,6-diformylphenol and 2,2′-dimethyl-1,3-diaminopropane. Brown colored compound 1 and green colored compound 2 are produced from the same reaction mixture as a function of temperature; 1 is formed from the reaction mixture in acetonitrile at low temperature (ca. 5 °C), while 2 is formed on heating the reaction mixture in acetonitrile. Crystals of compounds 1 and 2 are monoclinic (space group P21/c) and orthorhombic (space group P212121), respectively. Analyses of the crystal packing of the crystalline phases reveal that two-dimensional topologies are resulted in both 1 and 2 due to hydrogen bonding interactions. Variable-temperature (2–300 K) magnetic susceptibility measurements of the two compounds reveal that the metal centers in both the complexes are coupled by moderate antiferromagnetic interactions with J values (H = –2JS1·S2) −18.8 and −34.2 cm−1 for 1 and 2, respectively. Electrochemical analyses of 2 reveal that this compound exhibits two-step reduction couples at E½ = −977 and −1155 mV.
Syntheses, molecular and supramolecular structures, electrochemistry and magnetic properties of two diphenoxo-bridged dinickel(II) compounds [NiII2L(N3)2(H2O)2]·CH3CN (1) and [NiII2L(N3)2(H2O)] (2) derived from a tetraimino diphenolate macrocyclic ligand H2L, obtained on [2 + 2] condensation of 4-methyl-2,6-diformylphenol and 2,2′-dimethyl-1,3-diaminopropane, are presented. Compounds 1 and 2 are produced as a function of temperature from the same reaction mixture of the reactants.Figure optionsDownload as PowerPoint slideHighlights
► Syntheses, structures, and magnetic properties of two diphenoxo-bridged macrocyclic dinickel(II) complexes.
► Formation of two complexes from the same reaction mixture as function of temperature.
► Stabilization of one square pyramidal and one octahedral nickel(II) centers in a symmetrical dinucleating preorganized ligand.
► Weak interaction assisted two-dimensional topologies.
► Antiferromagnetic coupling between metal centers in the title compounds.
Journal: Polyhedron - Volume 30, Issue 11, 21 June 2011, Pages 1906–1913