کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1337434 | 979630 | 2012 | 7 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: A dinuclear manganese(II) complex {[Na2(H2O)4Mn2(μ-pmtz)4(NCS)2]·xH2O}n with 5-(pyrimidyl)tetrazolato bridges involved in 1D ladder-like chains: Synthesis, X-ray structure, magnetic properties and DFT calculations A dinuclear manganese(II) complex {[Na2(H2O)4Mn2(μ-pmtz)4(NCS)2]·xH2O}n with 5-(pyrimidyl)tetrazolato bridges involved in 1D ladder-like chains: Synthesis, X-ray structure, magnetic properties and DFT calculations](/preview/png/1337434.png)
A dinuclear manganese(II) unit of the composition {[Na2(H2O)4Mn2(μ-pmtz)4(NCS)2]·xH2O}n (1·xH2O) (x = 3 or 0.5), where pmtz = 5-(pyrimidyl)tetrazolate(1−), involved in 1D ladder-like chains mediated through pmtz bridges, was prepared and characterized by elemental analysis, FT-IR spectroscopy, simultaneous thermogravimetric (TG) and differential thermal (DTA) analyses, single crystal X-ray analysis and magnetic measurements, accompanied by DFT calculations. The magnetic data, treated with the spin Hamiltonian formalism, revealed a weak antiferromagnetic exchange mediated via the κ2N1,N7:κN2 chelating/bridging mode of pmtz. This finding was also supported by the DFT calculations performed on the experimentally determined geometry of the dinuclear manganese(II) unit at the B3LYP/TZVP and B2PLYP/TZVP levels of theory.
An unusual 1D ladder-like manganese(II) complex, {[Na2(H2O)4Mn2(μ-pmtz)4(NCS)2] ·xH2O}n (1·xH2O) (x = 3 or 0.5), involving two types of 5-(pyrimidyl)tetrazolato (pmtz) bridges has been prepared. The magnetic analysis revealed a very weak antiferromagnetic exchange mediated by the κ2N1,N7:κN2 chelating/bridging mode of pmtz. The non-isotropic axial zero-field splitting term, D, was essential for a proper description of the overall magnetic behaviour. A weak antiferromagnetic exchange was also supported by the DFT calculations.Figure optionsDownload as PowerPoint slideHighlights
► An unusual 1D ladder-like chain assembled from 5-(pyrimidyl)tetrazolato bridged dinuclear manganese(II) units.
► An antiferromagnetic exchange mediated through the tetrazole rings was found.
► DFT calculations at the B3LYP and B2PLYP/TZVP levels support a weak isotropic exchange.
Journal: Polyhedron - Volume 42, Issue 1, 25 July 2012, Pages 50–56