NMR shielding constants and chemical shifts in linear 199Hg compounds: comparison of three relativistic computational methods

V. ARCISAUSKAITE; MELO, J.I; S.P.A. SAUER; L.B.S. HEMMINGSENA

Thessaloniki, Greece

Conferencia; EUROBIC10 (10 th European Biological Inorganic Chemistry Conference); 2010

Aristotle University of Thessaloniki,

Since mercury ion Hg(II) can easily substitute native metal ions in metalloproteins and modify its’ coordination sphere leading to toxicological issues, it is important to investigate the coordination chemistry of Hg(II). 199Hg NMR spectroscopic technique has become a powerful tool in this study due to 199Hg NMR shielding constants and chemical shifts being very sensitive to the primary coordination sphere of Hg(II) [1]. From NMR parameters computational point of view, relativistic effects play an important role for systems containing heavy elements, such as mercury. Consequently, we employ fullyrelativistic four-component method within Dirac program [2] and less expensive two component methods: Linear Response Elimination of Small Component (LR-ESC) [3] and Zero Order Regular Approximation (ZORA) [4] within ADF [5] to calculate 199Hg NMR shielding constants and chemical shifts in model linear HgX (X=Cl2, Br2, I2, Me2) complexes. The aim of this study is to consider a method to study larger, more biologically relevant compounds containing Hg(II) and to investigate how different parameters like basis sets,nuclear models, gauge origin influence the outcome of the calculations.References :[1] M. Luczkowski, M. Stachura, V. Schirf, B. Demeler, L.Hemmingsen, V.L. Pecoraro, Inorg. Chem. 2008,  47, 10875.[2] DIRAC, a relativistic ab initio electronic structure program, Release DIRAC08 (2008), written by L.Visscher, H. J. Aa. Jensen, and T. Saue, with new contributions from R. Bast, S. Dubillard, K. G. Dyall, U.Ekström, E. Eliav, T. Fleig, A. S. P. Gomes, T. U. Helgaker, J. Henriksson, M. Iliaš, Ch. R. Jacob, S. Knecht, P.Norman, J. Olsen, M. Pernpointner, K. Ruud, P. Sałek, and J. Sikkema (see http://dirac.chem.sdu.dk).[3] J.I. Melo, M.C. Ruiz de Azua, C.G. Giribet, G.A. Aucar, P.F. Provasi, J. Chem. Phys. (2004), 121, 6798.[4] S.K. Wolff, T. Ziegler, E. van Lenthe, E.J. Baerends, J. Chem. Phys. (1999), 110, 7689.[5] Amsterdam Density Functional ADF, Release ADF 2009.01 (2009), written by E. J. Baerends, B. te Velde and collaborators (Amsterdam) and A. Rauk, T. Ziegler and collaborators (Calgary).(see http://www.scm.com).