Synthesis, structure and magnetism of new polynuclear transition metal aggregates assembled with Schiff-base ligand and anionic N-donor ligands Article - 2008

Rodolphe Clérac, Lollita Lecren, Yangguang Li, Qiong Wu

Rodolphe Clérac, Lollita Lecren, Yangguang Li, Qiong Wu, « Synthesis, structure and magnetism of new polynuclear transition metal aggregates assembled with Schiff-base ligand and anionic N-donor ligands  », Journal of Molecular Structure, 2008, pp. 339-345. ISSN 0022-2860

Abstract

Three new polynuclear aggregates [Co6(sae)4(N3)6(MeO)2(MeOH)2]0.5H2O (1) [Mn4O(sae)4(C(CN)3) (MeOH)3](NO3)MeOH (2) and [NaFe6(sae)6(MeO)6] (N(CN)2)H2O (3) have been synthesized with mixed ligands of Schiff-base (salicylidene-2-ethanolamine, H2sae) and various anionic N-donor ligands (N3, N(CN)2 or C(CN)3) and transition metal salts in methanol solution. Crystallographic data for 1 : trigonal, R3, a = 26.113(4) Å, b = 26.113(4) Å, c = 20.689(4) Å, c = 120, V = 12,218(3) Å3, Z = 9, R1(wR2) = 0.0753 (0.2176) ; for 2 : orthorhombic, Pna21, a = 20.746(4) Å, b = 13.357(3) Å, c = 17.992(4) Å, V = 4985.6(2) Å3, Z = 4, R1(wR2) = 0.0357(0.0969) ; for 3 : monoclinic, C2/c, a = 30.311(6) Å, b = 12.452(3) Å, c = 20.789(4) Å, b = 94.75(3), V = 7820(3) Å3, Z = 4, R1(wR2) = 0.0773(0.2299). Compound 1 exhibits a new rod-like [CoIII 4 CoII 2] structural feature. Compound 2 contains an unusual tetranuclear [MnIII 4 ] cationic core. Compound 3 possesses awell-knowncircle-like [FeIII 6 ] unit encapsulated a central sodiumcation.Magnetic properties of these compounds have been studied revealing the presence of (i) intra-molecular antiferromagnetic interactions in 2 and 3 that induce an overall ST = 0 ground state and (ii) CoII–CoII ferromagnetic interactions in complex 1

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