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

Assembly of MnIII ions into di-, tetra-, deca-nuclear coordination complexes, zero- to three-dimensional molecular frameworks: molecular spin flop to and short-range bulk magnetic spin flop ordering

“…axis arrangement forces d x 2− y 2 to be HOMO and mediates exchange via the μ-O methoxy bridges, which largely depends on the ∠Mn–O–Mn bond angle and average Mn–O (bridging) bond distances. 19–24…”

“…This J.-T. axis arrangement forces d x2−y2 to be HOMO and mediates exchange via the μ-O methoxy bridges, which largely depends on the ∠Mn-O-Mn bond angle and average Mn-O (bridging) bond distances. [19][20][21][22][23][24] The computed spin density on the Mn(III) center is 3.742 a.u., showing a highly delocalized nature, while the sizable spin density on the bridging O atoms (0.038 each O atom) reflects a spin-delocalized mechanism that is operative through the bridges. Due to the large ∠Mn-O-Mn bond angle in 2 (∼99.4°), the orbital orthogonality decreases, and subsequently, the ferromagnetic contribution to the J value.…”

“…[16][17][18] The exchange interactions such as superexchange and double exchange can be best understood in the phenoxo-bridged metal complexes. [19][20][21] Earlier reports suggest that the magnetic properties of the phenoxo-bridged Mn III complexes depend on various structural parameters, like the coordination geometry of the Mn ion, Mn-O-Mn bond angles, Mn-O bond lengths and Mn-Mn bond distances. [19][20][21] For instance, the exchange coupling constant (J) of some of these complexes decreases on increasing the Mn-O bond distance.…”

“…[19][20][21] Earlier reports suggest that the magnetic properties of the phenoxo-bridged Mn III complexes depend on various structural parameters, like the coordination geometry of the Mn ion, Mn-O-Mn bond angles, Mn-O bond lengths and Mn-Mn bond distances. [19][20][21] For instance, the exchange coupling constant (J) of some of these complexes decreases on increasing the Mn-O bond distance. 11 The anti-ferromagnetic interactions have been observed between the Mn III centers of doubly phenoxo-bridged dimeric complexes.…”