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

摘要

Synthesis, X-ray crystal structure and IR spectrum of {[Mn-II(Im)(6)]center dot 2(2-IC)center dot 2(NC)center dot 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 pi-pi 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. (c) 2006 Elsevier B.V. All rights reserved.