Tetranuclear manganese(II) complexes of hydrazone and carbohydrazone ligands: Synthesis, crystal structures, magnetic properties, Hirshfeld surface analysis and DFT calculations.

The complexes [Mn 4 (L1) 4 (N 3 ) 4 ] ( 1 ), [Mn 4 (L2) 4 (μ-N 3 ) 2 (N 3 ) 2 (OCH 3 ) 2 ] ( 2 ) and [Mn 4 (μ-L3) 4 (NCS) 4 ]·6CH 3 OH ( 3 ) [ L1 = N -1-(pyridin-2-yl)ethylidenepicolinohydrazonate, L2 = N -phenyl(pyridin-2-yl)methylenepicolino hydrazonate, and L3 = ((phenyl(pyridin-2-yl)methylene)hydrazinyl)((Z)-2-(phenyl(pyridin-2-yl)methylene)hydrazinyl)methanolate] have been synthesized, and their structures characterized. The structures of 1 and 3 can be described as tetranuclear and are formed from four Mn(II) ions bridged by four ligands. Complex 2 exhibits a centrosymmetric tetranuclear structure with two types of Mn(II) centers with double end-on (EO) azido bridges. All the complexes have similar magnetic behavior and exhibit weak intramolecular antiferromagnetic coupling, which is consistent with the oxygen-bridged square structures with large Mn–O–Mn bridge angles. Theoretically obtained J values of −1.7 cm −1 (for 1 ), −0.7 cm −1 (for 2 ) and −3.3 cm −1 (for 3 ) corroborate well the experimental results. Moreover, a Hirshfeld surface (HS) analysis was employed to gain additional insight into interactions responsible for packing of complexes 1 – 3 (with d norm and shape-index functions). Quantitative examination of 2D fingerprint plots revealed, amongst others, the dominating participation of H⋯H and H⋯C interactions in the molecular packing. [ABSTRACT FROM AUTHOR]