Experimental and theoretical exploration of magnetic exchange interactions and single-molecule magnetic behaviour of bis(η1:η2:μ2-carboxylate)GdIII2/DyIII2 systems. Issue 33 (1st August 2018)

• Record Type: Journal Article
• Authors: Ghosh, Sagar; Mandal, Shuvankar; Singh, Mukesh Kumar; Liu, Cai-Ming; Rajaraman, Gopalan; Mohanta, Sasankasekhar
• Is Part Of: Dalton transactions. Volume 47:Issue 33(2018)
• Page Start: 11455
• Page End: 11469
• Publication Date: 2018-08-01
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/c8dt02008f
• Languages: English
• ISSNs: 1477-9226

Abstract

Abstract : This investigation demonstrates differences in SMM properties and nature of magnetic exchange in closely related DyIII2/GdIII2 compounds. Abstract : The present report deals with the syntheses, crystal structures, dc/ac magnetic properties and DFT/ ab initio CASSCF calculations of two isomorphous bis(η 1 :η 2 :μ2 -acetate)GdIII2/DyIII2 compounds of the formula [LnIII2L2 (acetate)4 (MeOH)2 ] (1, Ln = Gd;2, Ln = Dy), where HL is ( E )- N ′-(3-ethoxysalicylidene)acetohydrazide. The two lanthanide(iii ) centres in each compound are symmetry-related owing to the presence of an inversion centre. Both compounds exhibit intramolecular ferromagnetic exchange interactions. The DyIII2 analogue is a single-molecule magnet (SMM) with U eff = 52.8 cm −1 and τ 0 = 1.52 × 10 −6 s. DFT calculations for1 and ab initio calculations for2 also reveal ferromagnetic interactions. Ab initio calculations of the SMM behaviour of2 and two other reported and structurally related compounds reveal the importance of the weak exchange interaction present between the two Dy III ions, and a relaxation mechanism has been developed to take into account the magnetic exchange interaction and to rationalize the observed difference in the U eff values.