Discrete and one dimensional extended Mn(III) Schiff base complexes with pseudohalides: Synthesis, structure and magnetic studies

• Published in: Inorganica Chimica Acta 2019-09, Vol.495, p.118997, Article 118997
• Main Authors: Pandey, Priyanka, Tripathi, Shalini, Shanmugam, Maheswaran, Butcher, R.J., Sunkari, Sailaja S.
• Format: Article
• Language: English
• Subjects: 1-D polymer; Antiferromagnetism; Azide/dicyanamide; Bonding strength; Chloroform; Hydrogen bonding; Imines; Ligands; Magnetic study; Mn(III); Schiff base
• ISSN: 0020-1693; 1873-3255
• DOI: 10.1016/j.ica.2019.118997

[Display omitted] •Three Mn(III) Schiff base complexes with pseudohalides (azide/dicyanamide), viz., [MnIII(L1)(N3)(H2O)]∙DMSO (1), [MnIII(L1)N(CN)2]n·H2O]n (2) and [MnIII(L2)N(CN)2(CH3OH)]∙CHCl3 (3) have been isolated and characterized structurally and magnetically.•Variations in the ring size and linker length show profound effect on the structures formed. While complexes 1 and 3 are monomeric, 2 shows 1-dimensional extended structure, with weak antiferromagntic coupling between the metal centers.•The presence of more than one d-d band in the solid state absorption spectra reveals the distorted octahedral geometry around Mn(III) ion due to Jahn-Teller distortion and existence in high spin state. This is well corroborated with dc magnetic susceptibility data.•The χMT = f(T) plot evidently signifies an overall weak anti-ferromagnetic coupling (J1 = −0.49 cm−1) between the Mn(III) centers in 2.•Overall, subtle differences in the starting components led us to isolate three different Mn(III) Schiff base complexes with distinct supramolecular interactions.•This is a particularly useful strategy for synthetic chemists to reveal new generation of SMMs or SCMs with improved magnetic properties. Slight variations in the Schiff base ligand and the linker length, led to the isolation of three different Mn(III) complexes under similar synthetic conditions that were characterized structurally and magnetically. [MnIII(L1)(N3)(H2O)]∙DMSO (1) and [MnIII(L2)N(CN)2(CH3OH)]∙CHCl3 (3) are azide and dicyanamide based monomers of Mn(III) with salophen and naphthophen as ligands respectively while [MnIII(L1)N(CN)2]n·H2O (2) is a dicyanamide based 1D-extended structure of Mn(III) with salophen ligand. Magnetic studies on 2 reveal antiferromagnetic interactions between the magnetic centers (J1 = −0.49 cm−1). All the three complexes have strong hydrogen bonding interactions connecting the monomeric units or polymeric chains into 2-D assemblies. The presence of supramolecular interactions within 1–3 was analyzed using Hirshfeld method.