Molecular structure of the molybdenum oxo-diperoxo compound MoO(O-2)(2)(OPy)(H2O): A computational and X-ray study

We have carded out a combined experimental and theoretical study of the mol ecular structure of the-MoO(O-2)(2)- (OPy)(H2O) coordination compound using X-ray crystallography and DFT-B3LYP computational method, respectively. Th e MoO(O-2)(2)(OPY)(H2O) Complex crystallizes in the orthorhombic space grou p Pmna with Z = 4, a = 6.9001(9) Angstrom, b =8.0471(1) Angstrom, c = 16.22 7(2) Angstrom, V = 901.0(2) Angstrom (3), and the X-ray data analysis yield s a bipyramidal-pentagonal coordination polyhedron for the Mo atom. The pyr idine N-oxide (OPy) ligand occupies the equatorial position, with the oxyge n atom of this ligand being located in the same plane as the four peroxo ox ygen atoms. The H2O ligand is situated trans to the oxo group, forming inte rmolecular hydrogen bonds with peroxo groups belonging,to two adjacent comp lexes. In our theoretical approach these intermolecular interactions were t aken into account by including two methanol molecules which form hydrogen b onds with the water ligand leading to a good agreement between the calculat ed and the experimental geometry. Our results suggest that it is necessary to take into account the presence of these interactions in order to reconci le the theoretical results to the experimental data, in particular the dist ance between Mo and the oxygen of water ligand. These results seem,to be a general feature for analogous bis-peroxo complexes that have been reported in the literature.