The Role of Hydrogen Bonds in Facilitating Planar Alignment of Mn(II) Halide 2,6-Bis(benzimidazole)pyridine-Based Complexes

Abstract

A series of Mn(II) halide complexes has been synthesized with 2,6-bis(benzimidazole)-pyridine (BBP), 2,6-bis(N-methyl-benzimidazole)pyridine (MBBP), and 2,6-bis(benzathiazole)-pyridine (BBTP) ligands in solvents capable of acting as hydrogen bonding donors and/or acceptors, resulting in Mn(BBP)(EtOH)X2 (X = Cl, Br), Mn(BBP)Br2·DMF, Mn(BBP)Br2·MeCN, Mn(MBBP)X2 (X = Cl, Br), [Mn(MBBP)(Br)(MeOH)2][Br] and Mn(BBTP)X2 (X = Cl, Br). The crystal structures of these materials were analyzed for the degree of planar packing of the anisotropic ligands. The exchange of hydrogen bonding donor and acceptor solvents (ethanol) for solvents only capable of accepting hydrogen bonds (DMF, acetonitrile) decreased the role of the solvent in the hydrogen bonding networks and also capped the NH groups of BBP, reducing the effectiveness of the BBP to form extended networks. Replacing NH groups in BBP with N-methyl groups (MBBP) and sulfur (BBTP) reduced the number of strong interactions between complexes, leading to a greater te...