Construction of a new double phenoxo bridged asymmetric manganese (III) Schiff base complex: Observation of ferromagnetic interaction within the dimer and antiferromagnetic interaction between dimers

A dimeric phenoxo bridged manganese(III) complex, [Mn2L2(OH2)(CH3OH)](ClO4)(2) [H2L = N,N'-bis((2-hydroxy-1-phenyl)ethylidene)ethane-1,2-diamine] has been synthesized and characterized. The structure has been confirmed by single crystal X-ray crystallography. The chi T-M value at room temperature is slightly higher than that expected for two non-interacting species with S = 2 (g = 2), that corresponds to two high spin manganese(III) centers. That chi T-M value increases gradually with lowering temperature to reach a maximum and then an abrupt decrease of chi T-M value is observed at lower temperature. A ferromagnetic interaction (J = 1.44 cm(-1)) between the manganese(III) centers within the dimer is counter balanced by the presence of zero-field splitting (ZFS, D = -2.03 cm(-1)) at very low temperature and possibly also by antiferromagnetic interaction between dimers (zJ = -0.06 cm(-1)). In order to investigate the single-molecule magnet (SMM) nature of the complex, alternating current (ac) magnetic measurements were carried out from 2 to 7 K under a 3.5 Oe ac field between 1 and 1000 Hz. (C) 2019 Elsevier Ltd. All rights reserved.