Synthesis, crystal structure and Hirshfeld surface analysis of Mn(II) coordination compounds with ONO-donor ligands derived from ampyrone

Abstract

Four manganese(II) coordination compounds, [Mn2(L1)2(NCS)2(MeOH)2] (1) [Mn(HL2)2(NCS)2(MeOH)2] (2) [Mn2(L3)2(NCS)2(MeOH)2] (3) and [Mn(HL3)2(NCS)2(MeOH)2] (4) have been synthesized from the reaction of MnCl2·4H2O, KSCN and Schiff base ligands derived from 4-aminoantipyrine (HL1= (E)-4-((2-hydroxybenzylidene)amino)-1,5-dimethyl-2-phenyl-1,2-dihydro-3H-pyrazol-3-one; HL2 = (E)-4-((2-hydroxy-3-methoxybenzylidene)amino)-1,5-dimethyl-2-phenyl-1,2-dihydro-3H-pyrazol-3-one and HL3 = (E)-4-((5-bromo-2-hydroxybenzylidene)amino)-1,5-dimethyl-2-phenyl-1,2-dihydro-3H-pyrazol-3-one) in methanol and the products have been characterized with single crystal X-ray diffraction (SC-XRD). The detailed studies involve the synthesis, crystal structure, FT-IR spectroscopy, UV–Vis spectroscopy, bond sum valence calculations, elemental and Hirshfeld surface analyses. In the case of 1 and 3, the phenolate bridged dinuclear MnII complexes are formed by chelating two Schiff base ligands, two thiocyanates and two methanol molecules and two crystallographically equivalent MnII ions are connected together by phenolate oxygen with the Mn···Mn distance of 3.1618(4) (in 1) and 3.1910(6) Å (in 3). In the case of 2 and 4, the octahedral coordination geometry of the MnII center in these mononuclear species is formed by chelating two Schiff base ligands, two thiocyanates and two methanol molecules. The presence of intermolecular hydrogen bond in 2 leads to the formation of molecular chains within the layers. Also, the presence of efficient π···π interactions between pyrazolone and phenyl rings and intermolecular hydrogen bonding in 4 lead to the formation of molecular chains within the layers. All of the intermolecular and intramolecular interactions have been studied by Hirshfeld surface analyses.