The blood‐red plutonocene complex Pu(1,3‐COT′′)(1,4‐COT′′) (4; COT′′=η8‐bis(trimethylsilyl)cyclooctatetraenyl) has been synthesized by oxidation of the anionic sandwich complex Li[Pu(1,4‐COT′′)2] (3) with anhydrous cobalt(II) chloride. The first crystal structure determination of an organoplutonium(IV) complex revealed an asymmetric sandwich structure for 4 where one COT′′ ring is 1,3‐substituted while the other retains the original 1,4‐substitution pattern. The electronic structure of 4 has been elucidated by a computational study, revealing a probable cause for the unexpected silyl group migration.
The blood‐red plutonocene complex Pu(1,3‐COT′′)(1,4‐COT′′) (4; COT′′=η8‐bis(trimethylsilyl)cyclooctatetraenyl) has been synthesized by oxidation of the anionic sandwich complex Li[Pu(1,4‐COT′′)2] (3) with anhydrous cobalt(II) chloride. The first crystal structure determination of an organoplutonium(IV) complex revealed an asymmetric sandwich structure for 4 where one COT′′ ring is 1,3‐substituted while the other retains the original 1,4‐substitution pattern. The electronic structure of 4 has been elucidated by a computational study, revealing a probable cause for the unexpected silyl group migration.
18 February 2010 in The Journal of Chemical Physics
The adsorbate structure of the first layer acetylene on the NaCl(100) single-crystal surface is investigated using polarization infrared spectroscopy in combination with low-energy electron diffraction (LEED) experiments, and potential calculations on the basis of pair potentials. In agreement with a previous study, a triplet of infrared absorptions in the region of the asymmetric stretch vibration of was observed and assigned to an adsorbate phase with translational symmetry determined in the LEED experiment. The polarization dependence of the infrared spectra is consistent with a parallel orientation of the molecules with respect to the surface. The number of molecules per unit cell is four to six as determined by photometric considerations. Total energy minimizations support a new structure model which contains five inequivalent molecules per unit cell in a herringbone arrangement. The application of a vibrational exciton approach demonstrates that this new structure model can reproduce the triplet spectrum observed in the infrared experiments.
22 July 2024 in Physical Chemistry Chemical Physics
The structure of the system NaCl(100)/( 3√2 × √2)R45°-C2H2 was investigated experimentally by means of quantitative LEED I(V) analysis and computationally using dispersion corrected density functional theory (DFT-D). Three different structure models with four, five, and six molecules were considered. The lowest reliability factors and thus best agreement of measured and calculated I(V) curves was found for the structure model containing five molecules per surface unit cell. Essential features of the experimental best-fit adlayer structure are supported by DFT. A slight inclination and lateral shift of twofold coordinated molecules away from the on-top position over Na+ adsorption sites is interpreted as compensation of strain between substrate and adlayer.