Isomorphous Catena Transition Metal Squarates [MII(C4O4)(dmso)2(OH2)2] (M = Co,Mn) and Magnetic Investigation into their Solid Solution M = CoxMn1–x |
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Authors: | Mihaela‐Diana Şerb Manfred Speldrich Prof Dr Heiko Lueken Prof Dr Ulli Englert |
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Institution: | 1. Department of Inorganic Chemistry, Faculty of Applied Chemistry and Materials Science, University POLITEHNICA of Bucharest, Polizu 1, 011061 Bucharest, Romania;2. Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany |
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Abstract: | The crystal structures of two new isomorphous transition metal squarato complexes MII(C4O4)(dmso)2(OH2)2] MII = CoII (3d7), MnII (3d5); dmso = dimethylsulfoxide] and their magnetic properties are reported. The compounds feature two symmetrically independent chains, in which 1,3‐bridging squarato ligands connect cations in distorted octahedral surroundings of pseudo‐symmetry D4h. From an equimolar solution of CoCl2 · 6H2O and MnCl2 · 2H2O a mixed‐metal coordination polymer crystallizes; it represents a solid solution and adopts the same structure as the corresponding monometallic compounds. The results of the diffraction experiment unambiguously proof the presence of both CoII and MnII cations in either independent site albeit no precise ratio between the metal cations involved may be deduced from these findings. The difference in the magnetic properties between CoII and MnII cations in the given ligand field has allowed us to establish their ratio in the solid solution more reliably than by X‐ray diffraction: Accounting for ligand field potential and spin‐orbit coupling of CoII and regarding MnII as a pure spin system, the calculations yielded a fraction of 73 % CoII in the mixed‐metal polymer. With respect to superexchange effects only weak antiferromagnetic interactions have been detected for the three coordination polymers. |
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Keywords: | Squarate complexes Cobalt Manganese Chain polymers Magnetic properties |
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