A Mixed Valence CoIICoIII2 Field-Supported Single Molecule Magnet: Solvent-Dependent Structural Variation |
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| Authors: | Susanta Hazra Cyril Rajnk Jn Titi&#x; M Ftima C Guedes da Silva Roman Bo
a Armando J L Pombeiro |
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| Institution: | 1.Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisbon, Portugal;2.Department of Chemistry, Faculty of Natural Sciences, University of SS Cyril and Methodius, 91701 Trnava, Slovakia; (C.R.); (J.T.); (R.B.);3.Peoples’ Friendship University of Russia (RUDN University), 6 Miklukho-Maklaya Street, 117198 Moscow, Russia |
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| Abstract: | One-pot reaction of the Schiff base N,N’-ethylene bis(salicylaldimine) (H2L), CoCl2.6H2O, and Ph2SnCl2] in acetone produces the mixed valence CoIICoIII2 compound CoIICoIII2(μ-L)2(Ph)2(μ-Cl)2]·(CH3)2CO·H2O (1). Our recent study already revealed that the same reaction mixtures in methanol or ethanol produced a heterometallic SnIVCoIII (2) or monometallic CoIII complex (3), respectively. Comparison of these organometallic systems shows that the 2,1-intermetallic Ph shift occurs in any of those solvents, but their relevant structural features (mononuclear, dinuclear-heterometallic, and trinuclear mixed valence) are solvent dependent. Geometrical structural rotation is also discussed among the related organometallic CoIICoIII2 systems. The AC magnetic susceptibility measurements indicate that 1 is a single molecule magnet (SMM), exhibiting a field-induced slow magnetic relaxation with two modes. The relaxation time for the low-frequency channel is as slow as τ~0.6 s at T = 2.0 K and BDC = 1.0 T. |
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| Keywords: | Schiff base mixed valence organometallic pH shift structural variation single molecule magnet |
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