Geometrical variations of two manganese(II) complexes with closely related quinoline-based tripodal ligands.

Structural analyses of the compounds di-μ-acetato-κ :'-bis-{[2-meth-oxy-,-bis-(quinolin-2-ylmeth-yl)ethanamine-κ ,','',]manganese(II)} bis-(tetra-phen-yl-borate) di-chloro-methane 1.45-solvate, [Mn(CO)(CHNO)](CHB)·1.45CHCl or [Mn(DQMEA)(μ-OAc)Mn(DQMEA)](BPh)·1.45CHCl or (BPh)·1.45CHCl, and (acetato-κ)[2-hy-droxy-,-bis(quinolin-2-ylmeth-yl)ethanamine-κ ,','',](methanol-κ)manganese(II) tetra-phenyl-borate methanol monosolvate, [Mn(CHCOO)(CHNO)(CHOH)](CHB)·CHOH or [Mn(DQEA)(OAc)(CHOH)]BPh·CHOH or BPh·CHOH, by single-crystal X-ray diffraction reveal distinct differences in the geometry of coordination of the tripodal DQEA and DQMEA ligands to Mn ions. In the asymmetric unit, compound (BPh)·(CHCl) crystallizes as a dimer in which each manganese(II) center is coordinated by the central amine nitro-gen, the nitro-gen atom of each quinoline group, and the meth-oxy-oxygen of the tetra-dentate DQMEA ligand, and two bridging-acetate oxygen atoms. The symmetric Mn centers have a distorted, octa-hedral geometry in which the quinoline nitro-gen atoms are to each other resulting in co-planarity of the quinoline rings. For each Mn center, a coordinated acetate oxygen participates in C-H⋯O hydrogen-bonding inter-actions with the two quinolyl moieties, further stabilizing the structure. Within the crystal, weak - stacking inter-actions and inter-molecular cation-anion inter-actions stabilize the crystal packing. In the asymmetric unit, compound BPh·CHOH crystallizes as a monomer in which the manganese(II) ion is coordinated to the central nitro-gen, the nitro-gen atom of each quinoline group, and the alcohol oxygen of the tetra-dentate DQEA ligand, an oxygen atom of OAc, and the oxygen atom of a methanol ligand. The geometry of the Mn center in BPh·CHOH is also a distorted octa-hedron, but the quinoline nitro-gen atoms are to each other in this structure. Hydrogen bonding between the acetate oxygen atoms and hydroxyl (O-H⋯O) and quinolyl (C-H⋯O and N-H⋯O) moieties of the DQEA ligand stabilize the complex in this configuration. Within the crystal, dimerization of complexes occurs by the formation of a pair of inter-molecular O3-H3⋯O2 hydrogen bonds between the coordinated hydroxyl oxygen of the DQEA ligand of one complex and an acetate oxygen of another. Additional hydrogen-bonding and inter-molecular cation-anion inter-actions contribute to the crystal packing.