| Abstract
| - The hydrido σ-dihydrogen complex RuClH(η2-H2)(PCy3)2 (2) reacts with the chlorosilanes HSiMe3-nCln(n = 1−3) to form the corresponding silyl σ-dihydrogen complexes RuCl(SiMe3-nCln)(η2-H2)(PCy3)2(3Me3-nCln). These complexes display a 16-electron configuration, as shown by NMR, by X-ray data inthe case of 3MeCl2, and by theoretical calculations. The σ-H2 ligand in 3MeCl2 has been located byX-ray diffraction, and the H−H distance of 1.05(3) Å compares well with the value obtained by DFT/B3PW91 (1.073 Å) as well as with the value of 1.08 ± 0.01 Å derived from the measurement of the JHDcoupling constant of 17.5 Hz for the deuterated isotopomer RuCl(SiMeCl2)(η2-HD)(PCy3)2. The seriesof model complexes RuCl(SiMe3-nCln)(η2-H2)(PMe3)2 (S3Me3-nCln) was investigated by DFT at theB3PW91 level. The most stable isomers have a structure that resembles the X-ray structure of 3MeCl2: i.e., a silyl σ-dihydrogen formulation. In the case of S3Me2Cl and S3MeCl2 a second minimum veryclose in energy was optimized and formulated as a hydrido σ-silane species. The influence of the numberof Cl substituents on Si and their location have been analyzed. The difference between 3Me2Cl on oneside and 3MeCl2 and 3Cl3 on the other side is highlighted both by NMR and DFT data and by theirreactivity toward ethylene. No reaction was observed for the latter complexes, whereas reaction with3Me2Cl produces the hydrido η2-ethylene complex RuClH(C2H4)(PCy3)2 (4). In the case of styrene, thearene complex RuCl(SiMe2Cl)(η6-C8H10)(PCy3) (5) was isolated.
- The hydrido σ-dihydrogen complex RuClH(η2-H2)(PCy3)2 reacts with the chlorosilanes HSiMe3-nCln (n = 1−3) to form the corresponding silyl σ-dihydrogen complexes RuCl(SiMe3-nCln)(η2−H2)(PCy3)2. NMR, X-ray, and DFT data are analyzed to evaluate how the number of chlorine atoms influences the silane activation and dihydrogen coordination.
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