Synthesis and characterization of two manganese(II) complexes containing di(4-pyridyl)sulfide (4-DPS) ligand: The effects of the counter ion and of the weak non-covalent interactions in the crystal structures of [Mn(4-DPS)4(H2O)2](ClO4)2·H2O and {[Mn(4-DP

From the reaction between the metallic precursor Mn(ClO4)2·6H2O and the flexible ligand di(4-pyridyl)sulfide (4-DPS) a mononuclear complex [Mn(4-DPS)4(H2O)2](ClO4)2·H2O (1) was obtained, while the reaction of MnCl2·4H2O with 4-DPS and KSCN afforded a neutral 1-D coordination polymer namely {[Mn(4-DPS)2(NCS)2]·2H2O}n (2). Compounds (1) and (2) were characterized by means of elemental analysis, thermal analysis (TG/DTA), vibrational (IR and Raman) and electron paramagnetic resonance (EPR) spectroscopies. Additionally, single-crystal X-ray diffraction analysis shows that in (1) the 4-DPS ligand acts in the monodentate coordination mode while in (2) it exhibits bridging coordination mode. The crystal structure of both compounds shows that each Mn2+ adopts a distorted octahedral geometry in which the equatorial planes contain four nitrogen atoms from different 4-DPS ligands. In (1), the axial positions are occupied by two oxygen atoms from two water molecules and in (2) by two other nitrogen atoms from two isothiocyanate groups. The supramolecular array observed in (1) was achieved through hydrogen-bonding and π–π interactions and in (2) the 1-D doubled stranded polymeric chain is extended by metal–ligand interaction. EPR spectra for both compounds are consistent with the X-ray structures containing isolated Mn2+ ions in distorted octahedral arrangements with very weak anti-ferromagnetic coupling.