title: Evaluation of (95)Mo Nuclear Shielding and Chemical Shift of [Mo6X14](2-) Clusters in the Liquid Phase.
abstract: [Mo6X14](2-) octahedral molybdenum clusters are the main building blocks of a large range of materials. Although (95)Mo nuclear magnetic resonance was proposed to be a powerful tool to characterize their structural and dynamical properties in solution, these measurements have never been complemented by theoretical studies which can limit their interpretation for complex systems. In this Article, we use quantum chemical calculations to evaluate the (95)Mo chemical shift of three clusters: [Mo6Cl14](2-), [Mo6Br14](2-), and [Mo6I14](2-). In particular, we test various computational parameters influencing the quality of the results: size of the basis set, treatment of relativistic and solvent effects. Furthermore, to provide quantum chemical calculations that are directly comparable with experimental data, we evaluate for the first time the (95)Mo nuclear magnetic shielding of the experimental reference, namely, MoO4(2-) in aqueous solution. This is achieved by combining ab initio molecular dynamics simulations with a periodic approach to evaluate the (95)Mo nuclear shieldings. The results demonstrate that, despite the difficulty to obtain accurate (95)Mo chemical shifts, relative values for a cluster series can be fairly well-reproduced by DFT calculations. We also show that performing an explicit solvent treatment for the reference compound improves by ∼50 ppm the agreement between theory and experiment. Finally, the standard deviation of ∼70 ppm that we calculate for the (95)Mo nuclear shielding of the reference provides an estimation of the accuracy we can achieve for the calculation of the (95)Mo chemical shifts using a static approach. These results demonstrate the growing ability of quantum chemical calculations to complement and interpret complex experimental measurements.
authors.affiliation: †Institut des Sciences Chimiques de Rennes, UMR 6226 CNRS-Université de Rennes 1-Ecole Nationale Supérieure de Chimie de Rennes, 11 Allée de Beaulieu, 35708 Rennes, France.
authors.forename: Thi Thuong
authors.initials: TT
authors.lastname: Nguyen
authors.affiliation: †Institut des Sciences Chimiques de Rennes, UMR 6226 CNRS-Université de Rennes 1-Ecole Nationale Supérieure de Chimie de Rennes, 11 Allée de Beaulieu, 35708 Rennes, France.
authors.forename: Julie
authors.initials: J
authors.lastname: Jung
authors.affiliation: ‡Unité de Glycobiologie Structurale et Fonctionnelle, UMR 8576 CNRS-Université Lille 1, IFR 147, Cité Scientifique Bâtiment C9, 59655 Villeneuve d'Ascq, France.
authors.forename: Xavier
authors.initials: X
authors.lastname: Trivelli
authors.affiliation: §Unité de Catalyse et Chimie du Solide, UMR 8181 CNRS-Université de Lille 1, 59655 Villeneuve d'Ascq, France.
authors.forename: Julien
authors.initials: J
authors.lastname: Trébosc
authors.affiliation: †Institut des Sciences Chimiques de Rennes, UMR 6226 CNRS-Université de Rennes 1-Ecole Nationale Supérieure de Chimie de Rennes, 11 Allée de Beaulieu, 35708 Rennes, France.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Cordier
authors.affiliation: †Institut des Sciences Chimiques de Rennes, UMR 6226 CNRS-Université de Rennes 1-Ecole Nationale Supérieure de Chimie de Rennes, 11 Allée de Beaulieu, 35708 Rennes, France.
authors.forename: Yann
authors.initials: Y
authors.lastname: Molard
authors.affiliation: †Institut des Sciences Chimiques de Rennes, UMR 6226 CNRS-Université de Rennes 1-Ecole Nationale Supérieure de Chimie de Rennes, 11 Allée de Beaulieu, 35708 Rennes, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Le Pollès
authors.affiliation: ∥Department of Physics and Astronomy, University College London, Gower Street, London WC1E6BT, United Kingdom.
authors.forename: Chris J
authors.initials: CJ
authors.lastname: Pickard
authors.affiliation: ⊥Laboratoire de Chimie et Physique Quantiques (LCPQ), Université de Toulouse III [UPS] and CNRS, 118 Route de Narbonne, F-31062 Toulouse, France.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Cuny
authors.affiliation: †Institut des Sciences Chimiques de Rennes, UMR 6226 CNRS-Université de Rennes 1-Ecole Nationale Supérieure de Chimie de Rennes, 11 Allée de Beaulieu, 35708 Rennes, France.
authors.forename: Régis
authors.initials: R
authors.lastname: Gautier
mesh_terms: D007554:Isotopes; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D056004:Molecular Dynamics Simulation; D008982:Molybdenum / Q000737:chemistry*; D011789:Quantum Theory; D012997:Solvents / Q000737:chemistry
chemical_list: D007554:Isotopes; D012997:Solvents; D008982:Molybdenum