Synthesis, crystal structure, spectral properties and catalytic activity of hexakis(imidazole)manganese(II) bisindole-2-carboxylato bisneocuproine bisdimethyl sulfoxide solvates {[MnII(Im)6] · 2(2-IC) · 2(NC) · 2(DMSO)}

Synthesis, X-ray crystal structure and IR spectrum of {[MnII(Im)6] · 2(2-IC) · 2(NC) · 2(DMSO)} (Im = imidazole, 2-HIC = indole-2-carboxylic acid, NC = 2,9-dimethyl-1,10-phenanthroline, DMSO = dimethyl sulfoxide) are reported. The manganese(II) ion has octahedral geometry with a MnN6 core. The crystal structure is completed by two NC, two 2-IC− and two DMSO solvate molecules. The individual cations are linked into chains running parallel to the a axis by four intermolecular hydrogen bonding involving two 2-IC−solvate. Moreover, these chains are connected by π–π stacking interactions which occur between neocuproine molecules related through inversion center. In IR spectroscopy, the compound spectrum is roughly similar to the imidazole one: (i) above 1800 cm−1, the bands are broad, but when focussing on some of them a doublet structure can be found; (ii) below 1800 cm−1, the bands are sharp and it is then possible to point out the modification of S–O band when this later is involved in bifurcated hydrogen bonding to a second solvate 2-IC−. The compound catalyses the disproportionation of H2O2; moreover an additional quantity of imidazole increases the reaction rate.