Electronic and Geometric Structure of the Cluster Compound Au-55 P(C6H5)(3) (12)Cl-6. A Computational Study

Relativistic density functional calculations have been carried out on the model cluster Au-55(PH3)(12)Cl-6 assuming a cuboctahedral or an icosahedral Au-55 metal core to model the experimentally suggested cluster compound assigned as Au-55[P(C6H5)(3)](12)Cl-6. Besides the overall shape of the metal core, the study focused on the unresolved issue at which sites the chlorine ligands are attached. The calculations reproduce characteristic interatomic distances within similar to 2 pm, with the exception of the Au-Cl bonds. Chlorine ligands were calculated to prefer higher coordinated sites whereas the previously postulated on-top coordination at the center of the Au (100) facets of a cuboctahedron was found to be unstable. In fact, the present model results suggest an ensemble of several higher coordinated sites. The often assumed cuboctahedral shape of the metal cluster core was determined to be slightly less stable than an approximately icosahedral shape. The calculations allow a rationalization of the difficulties faced in experiments that attempted to discriminate cluster isomers.     «

Relativistic density functional calculations have been carried out on the model cluster Au-55(PH3)(12)Cl-6 assuming a cuboctahedral or an icosahedral Au-55 metal core to model the experimentally suggested cluster compound assigned as Au-55[P(C6H5)(3)](12)Cl-6. Besides the overall shape of the metal core, the study focused on the unresolved issue at which sites the chlorine ligands are attached. The calculations reproduce characteristic interatomic distances within similar to 2 pm, with the excep...     »

ISI Document Delivery No.: 545DO Times Cited: 1 Cited Reference Count: 73 Genest, Alexander Krueger, Sven Roesch, Notker Fonds der Chemischen Industrie Over the years, N. R. and S. K. enjoyed numerous stimulating discussions with Prof. Hubert Schmidbaur, in particular on gold cluster compounds. The dedication of this paper to Prof. Schmidbaur on the occasion of his 75^th birthday is but a modest sign of gratitude for these fruitful interactions. In fact, the desire to calculate the electronic structure of a carbon-centered hexa-gold cluster compound, synthesized by Prof. Schmidbaur and his co-workers, ultimately lead N. R. and his group to develop a very efficient procedure for solving the relativistic Kohn-Sham equation of density functional theory. The present work also employed that approach, based on the Douglas-Kroll-Hess method. We also would like to thank Alena Kremleva for carrying out the slab-model calculations on the adsorption of chlorine atoms at gold surfaces. Computer time provided by the Leibniz Rechenzentrum Munchen is gratefully acknowledged. This work was supported by the Fonds der Chemischen Industrie. 1 Verlag z naturforsch Tubingen     «

ISI Document Delivery No.: 545DO Times Cited: 1 Cited Reference Count: 73 Genest, Alexander Krueger, Sven Roesch, Notker Fonds der Chemischen Industrie Over the years, N. R. and S. K. enjoyed numerous stimulating discussions with Prof. Hubert Schmidbaur, in particular on gold cluster compounds. The dedication of this paper to Prof. Schmidbaur on the occasion of his 75^th birthday is but a modest sign of gratitude for these fruitful interactions. In fact, the desire to calculate the electronic str...     »