2,3-Pyrazinedicarboxylates of cobalt(II), nickel(II), and copper(II); magnetic properties and crystal structures

Abstract

In 2 extended chains of copper ions are linked by double-bridging pyzdcH-groups while 3,4, and 5 have structures in which pyzdc2-ligands bridge metal centers to form extended linear chains. Magnetic susceptibility studies reveal antiferromagnetic interactions in 1,2,3,4, and 6 (6 is Cu(pyzdc)). The magnitude of exchange (-zJ = 0.033 cm-I for 1 and -J = O.l1,0.74,0.049, and 1.14 cm-' for 2,3,4, and 6, respectively) is discussed in terms of the structures and d-electron configurations involved.Key words: metal 2,3-pyrazinedicarboxylates, synthesis, X-ray structure, antiferromagnetism. Mors c l b : pyrazine-2.3-dicarboxylates mCtalliques, synthbse, structure par diffraction des rayons X, antiferrornagnitisme.[Traduit par la rCdaction]

Extended chain 2,3-pyrazinedicarboxylate complexes of manganese(II) and cadmium(II); synthesis and structure and magnetic properties

“…To compare complexes with different d" configurations it is appropriate to compare values of ~S'J (where S is the total spin) rather than J (15). The upper limit of this parameter for 1 is 0.43 cm-', comparable to, though greater than, the value 0.1 1 cm-I for [Cu(py~dcH)~],~2xH~O (4). A structural feature of the pyzdc2-bridge in 1 that is not seen in the depiction in Fig.…”

“…By employing dilute aqueous I solutions to obtain products, as described previously (4), polymer formation is slow and as a result all four compounds I reported here were obtained in crystalline form suitable for single crystal X-ray diffraction studies.…”

TG, DTA, FTIR and Raman spectral analysis of Zna/Mgbammonium sulfate mixed crystals

“…It is not surprising therefore, that many authors have investigated the nature of metal and ligand bonds by examination of their thermal and spectral properties [14][15][16][17]. In our previous papers, we described the thermoanalytical properties of Mg(II), Cu(II), Ni(II), Co(II) and Fe(III) complexes with pyridine and its derivatives [18][19][20][21][22][23][24][25][26][27][28][29][30].…”

A crossing double chain {[Cu(PZDC 2 ] · 3(H 2 O) · 2(IDZC)} n (H 2 PZDC=2,3-pyrazinedicarboxylic acid, IDZC=imidazole cation)

“…When the two ligands are combined, such as pyrazinecarboxylic acid, pyrazinedicarboxylic acid and pyrazineteracarboxylic acid, it is very likely to obtain some structurally novel and magnetically interesting complexes. For 2,3-pyrazinedicarboxylic acid, several complexes were previously characterized and magnetically investigated [3][4][5]. We report here on the first example of a crossing double chain complex bridged by a substituted pyrazine ligand, which exhibits ferromagnetic intrachain coupling.…”