Tuning the structures of manganese(III) (Schiff base) complexes: Syntheses, crystal structures and magnetic properties

•New coordination fashion of dinuclear entity derived from Mn(III) (Schiff base) and [FeIII(qcq)(CN)3]−.•Using same reaction precursors, different structure fashions could be obtained.•Field induced metamagnetic like behaviors were observed for these complexes.

Four new coordination complexes, [MnIII(3-EtO-salpn)(H2O)(CH3OH)]ClO4 (1), [MnIII(3-EtO-salpn)(H2O)2]·H2O·ClO4 (2), {[MnIII(3-EtO-salpn)(H2O)][FeIII(qcq)(CN)3]}·3H2O·CH3OH·CH3CN (3) and {[MnIII(3-EtO-salpn)(H2O)][FeIII(qcq)(CN)3]}·3H2O·CH3CN (4) (salpn = N,N′-1,2-propylenebis(salicylideneiminato)dianion; qcq = 8-(2-quinoline-2-carboxamido)quinoline anion) were synthesized and characterized both structurally and magnetically. The results reveal that complexes 1 and 2 are mononuclear MnIII structures crystallizing in different space groups, while 3 and 4 are dinuclear MnIII–NC–FeIII entities with different local arrangement of the subunits. Interestingly, the structures of these complexes are highly dependent on the reaction conditions though the reaction precursors are the same. Magnetic investigation indicates that intra- and/or intermolecular antiferromagnetic interactions are presented in complexes 1–4. Notably, these weak antiferromagnetic interactions could be overcome by high direct-current magnetic field, showing the field induced metamagnetic behaviors.

Graphical abstractFour new 0-D magnetic complexes constructed by manganese(III) (Schiff base) and/or the building block of [FeIII(qcq)(CN)3]− have been synthesized and characterized both structurally and magnetically. The result reveals the structural styles of 1 and 2 or 3 and 4 are interesting because they differs with each other in very subtle ways though they share the same reaction precursors. Field induced metamagnetic like behaviors were observed for these complexes.Figure optionsDownload full-size imageDownload as PowerPoint slide